N62 4.8 Oil Thermostat Gasket Leak (2007 X5)
 

Started off as a very slow oil leak (about a quart a month for 2 months) from an unknown location. Saturday it let loose and I had oil spewing from the drivers side front of the engine area. Local shop said he didn't want to touch it, dealer said between $2000 - $3000 job if it was indeed the gasket. So I tackled it myself. First off, I have been working on my own cars for 24 years and this was the most difficult job yet. Rate it a 8 out of 10 in difficulty for an experienced DIYer. Everything I found online was for the N62 or E70 WITHOUT the oil cooler thermostat. At least what I found gave me a general idea. I didn't have the time or patience to do a step by step but in short, here's what I did.

DISCONNECT BATTERY
1. Remove intake ducting and various snap off plastic parts.
2. Remove electric fan.
3. Drain power steering system, cooling and oil system.
4. Remove coolant expansion tank.
5. Remove alternator
6. Loosen Power steering pump and move to the side but leave hoses connected. This was horrible. Had to raise engine a few inches to make room to get it out.
7. May not be necessary but I removed water pump (which means you have to remove harmonic balancer and all belts) to make more room.
8. Disconnect two oil cooler quick disconnect lines top drivers side of engine compartment.
9. Remove drivers side front wheel and front half of wheel well cover.
10. Remove oil cooler thermostat. (2) Etorx E-10 bolts and (1) E-12 bolt. This was the worst. No room in there even if you get a ratchet setup on there. I suggest seeing if they sell Etorx box end wrenches. Would have come in handy.
11. Replace crappy $6 dollar seal, put it all back together, replace all the drained fluids and pray it all works ok.

Mine worked and spent about 21 hours of labor with my Dad helping. One hitch, I have a small vibration coming from the engine I can feel in the steering wheel and changes with RPM. I suspect the reuse and improper torque of the 8 torx bolts when I reinstalled the harmonic balancer. More to follow on that but open to suggestions from anyone that may sound familiar to.

That sounds like my worst nightmare. I would have torched the whole thing and hoped for an insurance pay out.

Did you use any high-temp sealant or silicone gasket maker on your new gasket? I've read other DIYs where they used a silicone gasket maker in addition to replacing the crummy seal since it is made of BUNA-N and is only rated to ~250 degrees F. VITON or some other high-temp gasket material would have been a better choice for BMW's reputation IMO. This is not a job I want to do twice.

No I didn't use any sealer. I thought about it but this one lasted 110,000 miles and I don't plan on keeping this one nearly that long. And hell no you don't want to do this job twice!

all that really?
 

I had a post reply from somebody that said it was a 10 hour job if you didn't have a oil cooler so it was a alternator bracket gasket and a 3 hour job if you have a oil cooler?
So I found the removal list and 21 hours here for the oil cooler gasket scary.
I wonder is it really necessary to remove the balancer?
Ok so now I will go find that other post to me

Have any more of you done this job since? Any word on how necessary it is to remove the water pump/harmonic balancer? Was lifting the engine a few inches needed? Dropping the subframe?

Seen mixed reviews about everything needed, just want to streamline this job as much as possible once I start ripping everything apart.

It will come down to the last two bolts on the oil cooler thermostat. I couldn't get them out with the tools I had, including quarter inch drive torx bits, which somebody said those worked for them.

This job is not a 3 hour job as it was also claimed before. More like 10 hours if you take your time (and you should). I didn't have to remove the water pump or the harmonic balancer when I attempted mine, then again I couldn't finish the job. So take my advice with a grain of salt.

If I had to do it again, I'd see if it was possible to access those two bolts through the wheel well. In fact I'd suggest you remove the fender liner and see if you have a good view of the sucker before doing anything else (please post pictures lol). I got this idea when I removed the passenger side fender liner to replace my washer pumps. Due to symmetry, I would expect to see the oil cooler thermostat clearly from that angle.

If there is still not enough clearance, I'd raise the engine couple of inches, which should be more than enough to get those bolts out.

I thought all X5 4.8 have oil cooler?

this job was the worst I've done in a very long time.

I had to use a small mirror to see the block. second guessing..... it might have been easier to remove wheel well liner.

I would not use any silicone,rtv, etc on the seal.

the most difficult part is replacing the alternator due to the power cable. the weight of the alternator and angle of attack makes impossible.


my back was so sore I let a shop do the valve cover gasket afterwards. :-(

I did this job a few weeks ago. Vehicle went from a few drips to spewing oil in about a week. Forum diy's and discussions and pictures of the thermostat housing were invaluable.

I didn't drop the subframe, or raise the engine, or go in through the wheel well. I removed the fan, alternator, tensioner, idler, and crank pulley (needed to get the alternator out). I laid on top of the engine, and worked blind. It is very tight in there, and I mostly had to use a 1/4" ratchet and sockets. What worked for me was to hold the ratchet in the palm of my hand, feel for the head of the bolt with my finger, then swing the ratchet into place. I took my time and was very careful to ensure the socket was properly seated on a bolt before cracking it loose - I didn't want to strip a bolt head. Took quite a while (maybe 12 hours over a few days), but got it done.

The old gasket was completely compression set (flat) and brittle. Replaced the gasket plus the two o-rings on the oil lines leading to the thermostat housing for about CAD $40.00. BMW charges $11 for each effing o-ring, the thieves.

No more leaks! Well, from there, at least - I think my valve cover gaskets are weeping :-(

Didn't think to take any pics, but would be happy to answer any questions.

that damn seal is just like all the e90 oil filter base. except it is on front top of the engine. 3 bolts and 45 min and you are done.

this will be our last bmw V8......

If you can get this job done in 45 minutes, even after disassembling everything to get in there, you are my hero. I'm pretty sure I took 1/2 hour per bolt.

Hey guys, thanks so much for all your help. Comparing everyone's info really helped get this job done today.

Removing the wheel liner didn't help much. There's too much in the way to accomplish anything from in there, except for got a small side view of the actual oil thermostat and it's bolts.

I removed the alternator, unbolted the power steering pump and moved it out of the way, leaving all hoses attached to it. Disconnected the hose from the bottom of the reservoir tho after sucking out the fluid.

I didn't need to lift the motor at all, or drop the subframe.

I disconnected the oil cooler lines from the oil thermostat, they were held on with a torn screw. Removed the oil thermostat blind from on top using E10 and E12 sockets with a 2-3 inch extension and ratchet.

That's about it, didn't end up being as terrible as I expected. The gasket was completely flat and felt like hard plastic, quite obviously just pumping out right out of it.

Put everything back together and she's running great and no more oil leak. Dripping coolant now tho, so to hunt down that is next...

I hope this info helps the next guy to do this job. Didn't have to remove the water pump. Lining up the power steering pump and alternator was probably the biggest pain next to getting those three E torx bolts out blind.

Any questions feel free to ask.

^ what options do you have on your X5? There was just not enough clearance to get those last two bolts out on mine.

Not sure what you mean by options, it's a pretty base model. No comfort access, no nav, no rear climate. Regular oil cooler.

The bottom bolts (E10) that you had the most trouble with? I had the most grief from the E12 on the top.

Congrats - glad to hear it went well. Did dropping the PS pump give you any more room?

My 2008 X5 is in the garage on jacks now. Oil leaks are what I am chasing. Pass valve cover replaced, drivers side valve cover is off, doing both upper timing cover gaskets and all O-rings I find along the way and there are several.
I plan to do the oil cooler gaskets and o rings before I assemble the valve cover again.
I'm hoping the timing cover will be easier with the alternator off the engine.
My drivers side valve cover was a major issue, there was not enough room to remove the number 8 coil. I ended up using a truckers 2" strap with ratchet to pull the rear of the engine a little towards the pass side to gain clearance after several hours lost.
There is no easy job when working on the BMW V8!
I appreciate the help offered here, it does make a difficult job much easier.

X5 e70, 2007, 4.8
Completed a week ago. Leak was so bad that I could fill in a glass in less thn 5 mins. No leaks since.

With the plastic protection and a left wheel removed, 2 of 3 bolts on a thermostat are easily accessible from the side with a couple of extensions. IMPORTANT: Wheel should be turned RIGHT. The last one is accessible from the upfront and it has more room for a hand with a ratchet.

Nothing was drained, radiator was covered with a towel from inside - it's a must(!). As an addition to the towel, I put a sheet of cardboard while removing the alternator as it's a massive beast.

Android-Iphone remote camera from Home Depot for ~$70 is a saver!

Did it for the first time in my life. With a good set of tools and absolutely no experience it took me approx 9 hrs to disassemble and 8 hrs to put everything back together.

Well I noticed a puddle of oil on my driveway after leaving for work the other morning. The oil level is still spot on, but I think the thermostat gasket spewed some oil. The leak seems intermittent (probably leaks out when the oil is thick and oil pressure is high).

Parts are en route. I don't know why I put up with the third-world build quality of BMW's engines. The engine will be nearly brand new via repairs by the time it hits 100k.

Don't wait for too long. Mine was leaking for a year - approx a quart/mo. A week ago it deteriorated to a glass/min. Luckily it had happened next to home. Don't even want to think what would I do in the middle of highway.

Entropy, take off the protection and check where the leak comes from. If you can't see the location and it's on the left side - welcome to the club.

Definitely the oil cooler thermostat gasket. Did you also do the oil line o-rings that attach to the thermostat (P/N 17227800958)?

I chose to replace these o-rings, rather than risk having to do this job again. The dealer charged me $11 each :mad: for the o-rings. The old ones looked fine - not flat, hard, and brittle like the thermostat gasket.

I replaced the o-rings as well. As said above they're $11 each, but I wouldn't forgive myself if I could but didn't and it started to leak

I installed new O Rings for sure, would not do the job without that addition. Way to much work to come back for a future leak.
Grinding down the Torx bit early would have saved me an hour or more. I fought it first before grinding down my tool, the tool is less than $10 to replace with one not ground down.

My first response disappeared. Anyways, had a slow oil leak since October. When in for unrelated work (and before I even noticed a leak), dealer diagnosed leaking valve cover and timing cover gaskets. When parking the car noticed a significant puddle of oil under it Sunday. Had it towed to an indy, and they've diagnosed the massive leak so far as front left area of engine but we're not sure....so I think I'm in this club as well. Unfortunately I really really don't have time to do this myself, and from some of the responses, I don't think I'd want to either (not really useable garage, would be on jack stands in ~20 deg weather.

Car had been leaking a quart every 2 months, not sure if that was the valve covers, this, or a combo. Really hoping just the oil cooler, and this will fix it.

I have had to do this before. Hopefully the one I have that is already ground down is the right size for this job. I'll be tackling it next weekend... in the cold, as my E46 is taking up the garage.

Mine is running with no leaks, now I find the AC unit is growling, could only hear it while in the garage with hood open. Another 2 days and $850. Grrrrrrr.

The mechanical build quality on BMWs is pretty sad. I will probably look outside of BMW once I am done with my E70. I'm sure reliability is one reason BMW was passed up by MB in 2016.

I feel ya.. I've had an E36, E46 and now my E70.. my 3 series were both great and I drove the piss out of them up to nearly 200k miles with only typical repairs for any vehicle with that kind of mileage. My X is a bit "special". I must say however that all of the woes I have experienced thus far have been with the motor. I've had a couple other issues with it that were "self-inflicted" (me being careless). And a few strange occurrences that only happened once and seemed to have fixed themselves. My door tweeter speaker BLARED static one day while the car was just sitting turned off in my garage. A couple minutes later it just randomly stopped and hasn't happened since. These cars seem to have their own personalities. I LOVE my X but sometimes feel like I'm driving a fancy, expensive, pretty, piece of shit with a luxurious interior and aesthetically pleasing exterior. And some of the engineering designs leave me scratching my head...

I've owned it less than a year though so we will see how things turn out in the long run...

Yep my E46 made it to 150k with routine maintenance. Your comment about the X being a shiny turd rings pretty true here (primarily only powertrain issues), but I couldn't imagine daily-ing a car without BMW interior anytime soon.

I think the quality is good but you have to know the German Government mandates they use recycled Plastic which affects a lot of our parts as they age.

I just replaced the seal in my vehicle . Right hand drive E70 2008. it took me about 1.5 hours from jack up to jack down.

1. passenger side wheel off
2. remove the little plastic bit where the drive shaft is
3. remove the thermostat housing .

I can imagine the difficulty for LHD vehicles

Xor, thank you for this. Just to clarify your steps (please correct me if I'm wrong):

1. Park vehicle with wheel turned right.
2. Remove wheel and plastic wheelwell liner.
3. Remove serpentine belt.
4. Remove alternator (was this done from above in the engine bay or from the wheelwell?)
5. Remove oil cooler lines from thermostat (do this while thermostat is still bolted to engine?)
6. Remove the 2 accessible thermostat bolts from the wheelwell.
7. Remove the last bolt (from above in the engine bay?)

Am I missing anything? Also, when you talk about protecting the radiator, do you mean the oil cooler radiator or the main coolant radiator? Thank you!

1. Park vehicle with wheel turned right.
Yes, but I was able to turn mine when the car was lifted (had a car on 2 stands).

2. Remove wheel and plastic wheelwell liner.
Correct

2.5 Remove the electrical fan to have enough room to work with an alternator
Take a picture of all metal and plastic clamps for all wires and hoses :thumbup:

3. Remove serpentine belt.
Correct, label the belt orientation

4. Remove alternator (was this done from above in the engine bay or from the wheelwell?)
Correct, done from above with MAIN radiator covered as you don't want to damage that fragile part. Alterator is very heavy.
- Undo all hose clamps and move all lines away.
- Remove the serpantine tensioner (will give you more room to work).
- Remove the belt pulley from the alternator (it's a must, the last boly is right under).
- Undo and remove 3 long bolts on the alternator
- Push the unit a bit down, twist a touch and slowly pull forward.
- When cables are accessible undo the electrical cables on its back. Some youtube videos are telling to remove the cables first (before pulling the alternator), but it's not about E70.

Before alternator re-installation make sure you tighten the nut (on the engine block itself) that guides the top alternator bolt, in my case it was yellowish. The outer thread on that nut is left-threaded (opposite from normal). This will save you a lot of time when you'll try to align that beast during re-installation.

5. Remove oil cooler lines from thermostat (do this while thermostat is still bolted to engine?)
No, I removed mine when the thermostat was out as there is one extra bolt to undo. Make sure you unplug the metal cooler lines from the radiator rubber lines first. And of course lines were bolted back to thermostat before the installation.

Find a good thermostat picture to see the bolts location. Most manuals are showing only 2 bolts, which is wrong in our case! Better find an actual product picture.

6. Remove the 2 accessible thermostat bolts from the wheelwell.
Correct, with several socket bar extensions, when the wheel is turned right, top left and bottom left bolts are accessible (both different T or E socket sizes.).

7. Remove the last bolt (from above in the engine bay?)
Correct. From above. Squeeze your hand inbetween all those hydraulic and coolant lines. Buy or "rent" a tiny camera in Home Depot to see what you're doing, have enough light. No rush, take your time, all is aluminum and fragile!!!

Am I missing anything? Also, when you talk about protecting the radiator, do you mean the oil cooler radiator or the main coolant radiator? Thank you!
Cover the main coolant radiator. You'll do a lot of hardwork from the engine bay.

I wiped everything I could. Make sure nothing gets into the thermostat opening when the unit is out as it's actually the engine.

This is great. Thank you! Wish me luck this weekend.

Well, I was successful. 7.5 hours. Not a fun job. No draining of cooling or P/S system.

To pull my fans out on our 2008 4.8L X5 I had to remove the top radiator hose , slip the fans up and out then reconnect, spilled less than a cup of coolant but I could not slip it out with the hose installed. Is there a way to do this without pulling the top hose off the radiator?
Congrats on doing the oil cooler in ONLY 7.5 hour. Much better than the 13 or more it took prior to this post.

The fan should just pull straight up. There is a tab on each side that holds it in. On the driver side, the tab on the fan housing that secures it to the radiator is actually hinged so it folds back onto itself so it can slip past the hose.

Thanks for that tip, I am replacing my AC compressor and need to install the fans again.
This is after Oil Cooler lines, coolant tube under manifold, valve ant timing covers and all fluids and hoses. I am ready for this project to end. Many tips here have helped.

Jealous here, so fast! Good job! :thumbup:

Any issues? Anything was done different? Tips for society? :popcorn:

No issues, other than I forgot to DISCONNECT THE BATTERY before taking the alternator out!... Doh! It arced on to a hose crimp fitting as I was rotating it. Luckily no damage done... just an oh-$hit moment.

I will add to the steps-list we already have going:

1. Park and jack up front of vehicle.

2. Remove left front wheel.

2.5. Disconnect the negative terminal cable from the battery.

3. Remove the front-half of the plastic wheelwell liner (it's split into two pieces) and lower plastic pieces as well. You will have to knock out the plastic rivets that hold the fender flare on. This can be done with a punch and a hammer. Hammer the center of the rivet in, which allows the rivets to be pulled out. Remove the fender flare and then remove the front-half of the wheelwell liner.

4. Remove the intake components, support beam above the radiator, electric fan (note that the driver-side tab is hinged, allowing it to fold back onto itself so it can slip past the upper radiator hose).

5. Remove serpentine belt, idler pulley, and tensioner.

6. Remove alternator (I also removed the two bolts holding the P/S pump, giving me a bit more room).

7. Take note of the position of the alternator guide nut. You will want to install the alternator with that nut in the same position.

8. Remove oil cooler lines from thermostat assembly (this can be done with long extensions from the wheelwell)

9. Remove the three bolts holding the thermostat to the block. I was able to remove the top bolt and forward-most bolt from the wheelwell. The rear-lower bolt I had to do from the engine bay.

10. Take out the thermostat assembly, clean it, replace gasket. Also replace the O-rings on the oil cooler lines. I used a pick-tool to get all of the old gaskets and O-rings off.

Whatever you do, be extremely careful with the torx-head bolts BMW uses. There is very little socket engagement and they can round-off easily. I purchased new bolts for re-installation (not necessary, but advised). Note that I didn't touch any power-steering or engine coolant lines... no draining necessary.

This would also be a good time to do the front differential fluid, since it is exposed.

Nice write up, will help many. I did this job with the fender cover in place. Took a lot longer. Make sure you order in the new plastic rivets to re install the fender cover. The old ones are a one time use part. A riveting tool can be used to install the new fender plastic rivets.

Hello everybody,
I just wanted to share my experience as I have repaired 2 this week . both 2007 4.8 but with MAJOR differences. first one went supper smooth no more then 4 hours total. did it from top of motor . removed fans ,top brace , alt and power steering pump. used android camera to help but not necessary. 2nd was a different story took more than 15 hours . the difference between the two . the 2nd has active steering the servotronic torque convertor is in the way and adaptive drive which uses a much larger power steering pump and alot more hyraulic lines, check the link to compare the differances . makes it much harder to access i did second one from the top as well but in hindsight probably would have been easier if i loosened PS rack and moved it a bit to left. RealOEM.com - Online BMW Parts Catalog

^ that explains my failure trying to do it from the top lol.

I still managed to do it from the top I used ratcheting etorx wrenchs and left the oil lines attached removed thermostat and lines as complete assembly(couldnt access center torx bolt holding lines too close to servotronic torque sensor) . but i really believe that loosening the 4 rack bolts and moving the rack over will make a world of difference. (not necessary with regular P/S)

I found the same interference with the steering rack components and left pipes installed on oil thermostat. Combination of accessing the bolts from the front and wheel well worked best for me. I replaced the female torx bolt holding the oil pipe to the thermostat with a conventional bolt...just because that torx bolt made me mad.

Seems I get to do this again on my sons E60 N62 for the second time. Yessir, one lucky dude.

It's much less room to work in E60. I was watching some youtube videos, and if it's nearly close to 7-series, you may need to drop a subframe :(

I done it before and just need to lift engine and cuss a little. No need to drop subframe.

Just about to button up this job. 2008 with active steering. It actually sounds worse than it is. Step one: clean and dry the entire area thoroughly before doing anything else. Adds a lot of visibility, that's half the battle. After removing fan & alternator I tightly strapped the PS pump to the lifting lug to keep it well out of the way without having to disconnect anything.
The bottom two bolts of the stat are easy enough to get at. I found that with the wheel off this was the clearest shot at the top bolt: https://uploads.tapatalk-cdn.com/201...aecb23850d.jpg
It takes a very long 1/4 extension plus UJ to get at but it works.
I've not tried pulling it out with the hoses attached, doesn't sound like a bad idea tho. I removed the retaining torx bolt for the oil lines with a torx bit and a small ratchet spanner:
https://uploads.tapatalk-cdn.com/201...00c4d42f14.jpg
You'll have to just loosen it and do the rest by hand since eventually you'll be jamming the bit against the active steering stuff that's in the way.

All in all a hoist really helped making small work of it but it could probably be done on jack stands. I'd say about 6ish hours for someone who's done it before, plus obviously however long it takes to clean the muck away first.

Just a follow up on our 2008 X5 4.8L. Since replacing the oil cooler Orings, Coolant tube, Intake manifold gaskets, water pump o'rings, all heater and radiator hoses, valve cover gaskets, timing cover gaskets, many O'rings and seals, changed out all fluids, tranny 2 times, front differential 3 times, for some reason it kept coming out dirty but I had the fluid tested and it tested perfect so no worry's installed a new AC compressor and condenser a new front drive shaft and last a new drivers side front wheel bearing. Now a few thousand miles of leak proof road time I am starting to like and appreciate our X5 again. From Thanksgiving till February I was hating this car and the people that made it. I put $2,500 in parts and an enormous amount of labor into these projects but now the car seems like brand new. Runs perfect. Last trip, 1,100 miles it got 20 MPG and we ran hard, 75-85 mph almost all the time with the car loaded heavy, 3 people and a lot of gear. Should a car need all these repairs at 100,000 miles. I say Hell No, a Toyota or Honda would not have needed this, heck my Ford Fusion did not need any of this done but this is a really nice driving car now that it is fixed. I hope to run it another 100,000.
If all these jobs were done in a shop I think it would approach $10,000 rather than my parts only cost of $2,500.
My last fear with this car is that the coolant gasket at the rear of the engine behind the transmission bell housing will start leaking some day. I did not pull the tranny to replace this last gasket.

Now 8 mos since all the repairs. The X5 is still totally clean. I do not miss the old oil mess underneath. I did use about 3/4 quart of oil in 5,000 miles but I am OK with that. When I get bored I will pull off the valve cover vent hose and look for oil in the tubes. It should be dry but you never know. Now at 106,000 miles.

We're at 9 months, but less than 5k miles since the repair. But from checking the oil level, I think we're on pace for a quart in 5k miles. I think it's normal consumption for these engines.

I'm about 8 months from the repair and no leaks. However, I consume a quart every 2k miles. No smoke, though.

You might check the crankcase ventilation tubes where they come from the valve covers and plug into the intake at the throttle body.
Those tubes should be clean inside. If they are coated or dripping oil you have your oil leak. If they have oil in them there is an air leak somewhere in the upper engine. Could be as simple as your dip stick O ring or the Valve cover cap where you add oil. These engines need to be sealed tight or they start sucking oil into the intake.

Glad you guys are having similar luck with a dry engine.
This week it looks like my AC idler pulley is failing and my wife has the car 500 miles away! I hope it makes it home ok.

I'll check again. I replaced the diaphragms about a year ago. Good call on the dip stick o-ring.

Also, it's possible that the bearing that's going bad for you is actually the A/C compressor pulley bearing. I just replaced mine. $15 fix. https://youtu.be/5qd0e-vVxQA?list=FL...47Ua4QMSSZxMww

I just installed a new AC compressor in January. I hope it is still good. It was blowing cold when she left.

Update
 

I did do it with a friend which does help. The customers car is a 2007 BMW X5 4.8i. This one had the oil cooler. It took us about an hour and a half to take it out, and I'm estimating 2 hours to put it in. We are currently waiting for the parts.

It wasn't that hard. Removed fan, belt, alternator, slid out ps pump, removed upper radiator hose, removed the 2 oil cooler lines, and then removed oil cooler thermostat. We removed the e torx bolts by removing driver side wheel, using an extension and a u joint.

We plan on replacing the seal as well as 4 oil line o rings. I'll update to see if it works

Update

Yep. No signs of oil leak. Definitely wouldn't have wanted to attempt the one with no oil cooler. That looks like a pain in the butt. Valve cover gasket job also big pain in the butt. If I had to do it again, I'd definitely remove intake manifold and fuel rails. It was just so much harder to maneuver and make sure the gasket was seated properly. This car was poorly designed.

100% agreed.

it looks like I might have this dreaded leak on my 2007 4.8i again. I checked my service records and BMW replaced my oil cooler thermostat and gasket at 74,000 miles when I still had an extended warranty. I'm at 140,000 miles now.

Those that had this leak, at what mileage did it start?

I'm wondering if the gasket only last 70k ??

I'd have to check my records but our leak was somewhere around 135k. We've only owned it from 120k or so. I have dealer records but there's no record of any of the common oil leak repairs but I have to imagine it leaked and was fixed before we got it. So yeah, wouldn't surprise me if they only last 70k or so.

Which is great because that probably means other things are about to go since we're at 147k now.

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Mine started around 75k. I'd say you're due for a replacement. How is it so hard for BMW to develop a gasket material that doesn't turn to stone after 75k miles? Seems even the cheapest car manufacturers figured this out 20 years ago. 100% planned obsolescence on BMW's part. My wife's Mini had a spark plug well (engine has a BMW head/valvetrain) full of oil at 40k miles. Gaskets were already turning hard. Unbelievable.

Now of course I can't find any record of it, but I could've sworn I had read that BMW uses recycled materials for their gaskets to be environmentally friendly. But really no idea if that's true

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It's a disgrace. Have you ever heard of a Toyota V8 leaking oil? The X5 V8 has at least 6 spots that are guaranteed to leak oil, and many are fairly major jobs.

This really pisses me off. What kind of cheap ass materials are BMW using for their gaskets. We gotta do all this work every 75k just to replace a $6 gasket? I'll gladly pay for a gasket costing 3x more if it will last 2x as long.

truly unbelievable.

Mine was replace at 77,997 miles. Probably started leaking a couple of thousand miles earlier. Right on the money.

I think the fact that our engines run hotter than most V8's is a contributing factor to why these gaskets harden up over time. I swapped my thermostat with a lower temperature one in the hopes of preventing this. Not counting on it though.

Our engines don't run any hotter than other modern engines. In fact, I'd say with the oil coolers that most BMW engines have, they run cooler than other engines.

If by modern you mean newer turbo BMW engines, you're right. But you will find stock thermostat temperatures in the 160-210 range for the V8 LS engines from the same era as the E70, similar to Toyota V8s from the same era. Our stock thermostat is rated at 221 degrees, and I was constantly getting 230 with that thermostat (110 C). Oil temperature is probably higher. I wouldn't call that a cool running engine.

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The 4.8 seems to run cooler than my E46 M3. If I'm to just go off the oil temp needle.
Which kind of surprised me considering it's a large V8.


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E70 doesn't have an oil temp needle? Also it's beyond me how a 105 degree thermostat on the 4.8 runs cooler than an S54 with a 80 degree thermostat. I'd be interested in actual numbers read over OBD port.

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The 4.8iS has a oil temp gauge. Same range as the E46 M3 and it consistently sits lower and rises slower.
Didn't think about the coolant temp tho.



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Has anyone done this job on a E53 4.8 with the oil cooler.

Mine has a very very slow leak (not losing any measurable amount of oil, just some drops) but I want to tackle this before the gasket let’s go on the way back home after I’ve been snowboarding all day.

Here’s a pic: https://xoutpost.com/1114744-post25.html

This is a right hand drive vehicle without “servotronic” steering and it doesn’t have the fancy water cooled alternator neither.

Been there done that on my '08 4.8i. Yes, very difficult...there were moments when I thought I would never get the last bolt out. But, persistence and tool creativity paid off in the end. Just something all of us V8 owners know we have to do sooner or later.



FWIW, it was difficult on my E60 545i as well due to having active steering components blocking access.

I need to replace the oil cooler thermostat gasket in my 2007 e70 4.8l. Also while I am there I would like to get the valve cover and upper timing cover gaskets replaced as well. Does it make the thermostat gasket job easier to have the valve cover removed? Thank you.

No, it doesn’t because the alternator bracket is accesssd from below the car or through the wheel well and requires removal of the alternator. It hasn’t anything to do with the top of the engine.

I see. Thanks for your reply. My car has adaptive drive. Will this make it harder to reach the thermostat bolts? And in this case what's the best angle of attack, top, bottom or wheel well?
Thanks.

Were you able to do this? How was it?

So this is my problem. The PS pump can't be pulled out since the bar in the bottom is in the way. Did anyone remove the high pressure line going to the PS pump (yellow arrow)? I know the instructions on this thread had no mention of it unless I missed it. Any tips are appreciated.

https://www.dropbox.com/s/9ug73e0ur0...image.png?dl=0

I ended up taking this to an indy BMW mechanic. It was $850 for part and labor.

Same here. It was a real bitch of a job and I couldn’t easily reach the bolts. And I was under time pressure.

Shop said they dropped the subframe. Don’t have the tools / jacks etc to do that at home easily.

Shop did it in less than 7 hours. They didnt say how they did it but it was done same day. Dropped it off at 9 am they called me at 4 pm to pick up the car. I was surprised but hey whatever :)

ok so oil cooler thermostat gasket was replaced, valve cover and upper timing chain cover gaskets were replaced as well. I am still seeing oil collecting at the bottom of the diff. where the heck is it coming from? :) .. it's like a drop of oil hanging and ready to fall on my garage floor .. so not a heavy leak but oil is leaking from somewhere. any idea? much appreciated!

Is it clean fresh oil or dark nasty stuff that could be from the previous leak?

Spray it off with some degreaser and wait and see if it comes back. It is hard to get all of the oil off from an engine when there has been a leak so it could be a remnant....

Hopefully it isn't the oil pan... That would require a full front frame drop and removal of the front axles to fix ~$50 in gaskets...

-Rich

I did clean the old oil very well. Everything looked nice and dry. I also changed oil so the oil on the diff looks new oil (golden color). Would an oil pan gasket leak collect at the bottom of the front diff?

It could. Oil tends to run down things and collect at a low point. I would double check the VC gaskets by wiping along the edge with a clean paper towel to look for leaks.

I just did an engine swap and redid all of the gaskets on my 4.8i so it is somewhat fresh in my mind... :)

Is it definitely engine oil or could it be power steering fluid? Genuine CH11s is green when new but Febi and some others is not very green and the green seems to fade over time. Power steering leaks can come from the lines or potentially from the rack (although that was more of an issue on my e46s).

If you changed the diff oil then the process is to add it until it overflows much like the transmission so it could be just spill over that is just running downward.

Do you have any other spots or oil run lines on the belly pan?

If everything is clean and dry then you should be able to track it down (not that there is any room to see anything in a 4.8i e70).

-Rich

I changed the engine oil. But thanks for the tips. I will take a closer look.

Anyone have a parts list for this repair?

N62 4.8 Oil Thermostat Gasket Leak (2007 X5)
 

It’s just the alternator bracket gasket. It is good to replace the two o-rings on the oil cooler line as well while you are down there. Takes a few minutes. I had no problem reusing the bolts. Some replace the bolts with a hex bolt rather than the original torx bolts.

https://www.fcpeuro.com/products/bmw...yABEgI-2vD_BwE

https://www.fcpeuro.com/products/bmw...-17227800958oe



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Thank you for the info

Got it all buttoned up. Overall not too bad of a job. Took me approx 6 hrs. The only thing that I would add to the parts list is plastic rivets for the fender flares. I got to 3 of the bolts thru the wheel well so I had to drill out the rivets

Good job. From above it’s blind so it sounds like you got a good look. This job could probably be done in 3-4 hours if you ever have to do it again.


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just wondering if people actually just purchased the gasket or the actual new unit.

but i wonder if the unit is just a metal part (no component to break)

gasket only cost less than $20 and the part is over $100

You can replace just the gasket, I haven't heard of the termostat being a failure point.

The Mahle gasket is a Fluoroelastomer(viton) gasket which is better than the stock/oem material so I recommend that... The E70 part number for the one with the oil cooler is: B32856

I bought one from rockauto for under $4. The job is a pain but it is doable on an e70 4.8i without dropping the subframe. It is an easier job than the valve cover gaskets...

-Rich

Word to the wise about thermostat removal
 

For anyone planning to replace the oil thermostat gasket, don't do what I did. I removed two of the three bolts holding the thermostat to the block (the top bolt and the lower/front bolt). Then I removed the T45 bolt holding the oil lines to the thermostat. When I tried to pull the lines out of the thermostat, the thermostat cracked around the third bolt (lower/rear). So if you plan to remove the lines from the thermostat, do it while all 3 bolts are still holding the thermostat to the block. That aluminum casting around the lower/rear bolt is pretty fragile apparently. So now I am buying a good, used thermostat. As if the job wasn't a pain enough, lol.
James

I am doing the alternator thermostat gasket as a preventive maintenance. Took the E12 bolt and one of the E10. Fighting with the 2nd E10. Ordered an 1/4" swivel E10 socket from amazon for the 2nd E10 bolt. Will post the results with the swivel bolt when I get it

Any advise on how to tighten the bolts after the gasket replacement? A torque wrench is out of the question. Snug tight and a quarter turn will do it?

Use a torque wrench on another bolt to get a feel for how tight it is when using the wrench you are forced to use in the tight space available to you. Torque a bolt to spec, use your actual wrench to see what it feels like at that torque. ON install of the actual bolts try to match what you felt in the test. That is all you can do. When I did mine I removed the inner fender liner and the driver side front tire. I was able to go in with a long extension from the wheel area for some of the bolts. I was also doing the high pressure oil cooler line seals and I do not remember which bolts I accessed through the fender. It has been 5 or 6 years now and I forget.

Westlotorn, Thank you so much for the reply. Although I completed this job a month ago, I am sure it will help someone else in the future

In my case, I didn't torque it, but just went by feel and I did the tightening through the alternator opening and you cannot put too much pressure to over-tighten it anyway.

As for the bolt removal, I finally had to do just what you described. removed the driver side wheel and was able to see and access the bolt directly from there.

I think the key is to use the right tool from the beginning, a.k.a, E10 with 1/4" drive. If you try with an E10 3/4 drive, not only that it won't fit right , but the angle will cause it to slip and bruise the torx head, then loosening that bolt from the alternator opening is impossible since you can not apply pressure from there

When the bolt was handled from the wheel well side, I could put all the pressure I wanted to it so the socket doesn't slip on the Torx head

I will post some pictures I took when I did this job.

Glad you got it fixed, the hard to reach bolts make me mad at the engineers. They did not even consider the repair person when building this car. They drive top notch but not easy to fix.

The E10 socket in the picture is a 1/4" swivel E10 socket I bought from Amazon and modified it a bit, so it swivels , but not too much

Hope this helps

Did anyone torque the E12 and E10 bolts?

For ease of removal on the E10 bolts, I used an 8mm 12 point gear wrench.
It fits perfectly on the heads. I actually had to add an additional wrench to it for leverage and the bolts cracked out great. I'm in the rust belt in Ontario Canada, but the bolt heads were in good shape. I used the same method for installation. I used my right hand to hold the wrench onto the bolt head and my left hand for swinging the wrench up and down. Nothing helps your ribcage doing this job though

For the record, I do own Etorx sockets, but I dropped my good one trying to get the rearmost lower bolt out, and it has yet to be found. After some trial and error using 6 point sockets on the one I did get out, I stuck the 12 point 8mm wrench on it and couldn't believe how well it fit. :thumbup:

I'm in the middle of this job right now and FUCK!!! I just want to give up. Can't get any leverage on the E10 bolts at all. First I tried from going in blind from up top and then from the wheel well. I can see the oil cooler and bolts, but can't fucking break it free. I tried using about 4 extensions almost 18 inches long too. I'm scared I will round off on the bolts. This have got to be one of the worse jobs i've done. I've done valve covers, uppper timing covers, valley pan, transfer pipe, etc... I never had this level of frustration until now.

I just reached down from the top. I am sure I sacrificed some skin but no auto repair job goes well until you give a little blood to the car gods.

IIRC I just used an e-torx on a regular 3/8 ratchet directly. I did it by feel but e-torx is good for that and doesn't strip out as easily as a hex head as long as you get the right size on it...

After I removed the belts and alternator it wasn't that bad. I am not a huge guy with big forearms though. :)

I don't think i did any of the work from the bottom but it has been a while now.

Make sure you get the viton version of the gasket so you don't need to do it again. It is better than the OE gasket!

-Rich

I think whoever replaced the gasket the last time kinda mangled the head a bit, because I can't seem to push that e-torx all the way in, it's just kinda grabbing the tips.

It's not leaking right now, but since I had to replace the alternator, I thought i would go ahead and replace the gasket while I'm at it. Didn't think I would have this much trouble.

I don't have time to mess with it anymore so I gave up on the gasket replacement and just put everything back for now.

I'm sure I will have to tackle this job again in the future.

One downside of etorx is that many people don't have the right tools and mess them up...

The next size up etorx will often work on the bolt but will mangle it. Some also use spline or even a 5/16 socket on them which can work but isn't right.

Normally I would hammer the right size socket on them to straighten it out and then replace the bolt. That isn't a great option given the clearances of the oil filter housing.

You could try a spline socket if all else fails.

-Rich