N62 4.8 Oil Thermostat Gasket Leak (2007 X5)

[bdcanetti]

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.

[Suge206]

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

[X5bimmer88]

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.

[bdcanetti]

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!

[Ron07x5]

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

[zanderch]

Originally Posted by Ron07x5

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.

[SeanC]

Originally Posted by zanderch

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.

[fast4d]

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. :-(

[LightlyToasted]

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.

[fast4d]

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......