Expansion Tank Busted
 

Ive searched the threads and I havent found any complaints of a coolant tank cracking. My 4.8is expansion tank just cracked and all the antifreeze came out. Anyone ever had this problem? Is it worth getting a oem or a aftermarket. Should I replace all the hoses while im at it?

OEM replacement is the way to go.

Expansion tanks failing is a very, very common thing for most BMW's.

Your mileage will indicate what you should do as far as hoses are concerned. However, from personal experience and everything I read, once you start replacing components on your cooling system it stresses the old components you don't change and they start breaking as well. Probably best to replace the entire cooling system if you have anywhere near about 90k miles or so. I would use OE parts, but that is up to you.

Can someone please explain to me how replacing a cracked expansion tank will "Stress" the other components to failure? I am really interested because mine is leaking and I don't see how replacing this will cause my other components to fail.
Maybe a new water pump will affect old hoses and such, but a new expansion tank won't have any effect on your other components.. Unless I'm wrong

I am not sure if "stress" was the best word I could have chosen in the above post, but for one reason or another it always seems that at higher mileage, when you start to have components of the cooling system fail, many others are quick to follow.

Not in all cases. I replaced the waterpump, exp tank and upper hose ass'y at 105k miles. System is fine at over 150k miles.

I replaced my tank this Friday. I also replaced 5 of the 6 cooling hoses and new fluid. So far so good.

I too can't see it stressing the other components. People get failures of other items because it is time for them to fail. When you replace the tank, which was losing pressure, and leaking, you basically close the weak point in the system. What happens then, is the hoses and other stuff have to start working again at full pressure.

I think the component failure is when those people neglect the leaking tanks, and replace them when they leak like the Hoover Dam. Like all the fluid emptied out. The hoses are old, and now they are relaxed, because of the low pressure, rubber does have memory. Then all of a sudden, new tank, the cooling system is at full pressure, and this shocks the other components.

Replace your dripping tank right away, and I think you should be fine. Replace the expansion tank fill cap as well. Only reason I replaced the hoses, is because I am insane, and do preventative maintenance way ahead of time.

Correct. Never said in all cases. However, if you have any of the original cooling system parts at 150,000 miles, you are running on borrowed time. I feel your particular case should be taken as the exception and not the norm.

I agree it's the exception. Gone this far and I am going to ride it out to the failure, let AAA membership pick up the tow $s.

Currently in Dallas/Ft Worth TX area, 110 deg heat and done two tows of 6k lbs, sitting in stop and go construction traffic I have see the outside temp reading up to 122 deg. Suprised it's not failed something thus far!

lol. Yours must have been made out of unobtainium and not the plastic the rest of us got.

Hahaha! The fail is first thing on my mind sitting in traffic, I watch the temp gage and for the telltale steam plume!

Expansion tank failure is all to common on bimmers, HERE is a link to the expansion tank for your 4.8is, personally I prefer the genuine BMW tanks.

Inspect the hoses, if the tank cracked most likely the upper and lower radiator hoses are also pretty worn.

And here's the DIY

http://www.xoutpost.com/miscellaneou...ement-diy.html

I replace the expansion tank in all of my bimmers between 80 and 100k as preventative maintenance. When the tanks go, at least in the e46, it dumps all of the coolant in a matter of seconds.. a lot of people have cooked their engines because of this. BMW aluminum block and heads are very sensitive to overheating...
The e53 expansion tank was by far the easiest I've done in a BMW so far...

Did you guys pay for the repair to the expansion tank? or DYI ?
Mine busted today. See my post..

Depending on mileage. It might be a good idea to replace all hoses, tstat, and check other components. New coolant as well.

I replaced my tank due to a small leak a few thousand miles ago. I was being cheap, and instead of ordering the OEM tank for $80, I ordered an aftermarket one that ECS sells, for nearly half the price. I don't normally go this route...But I took the risk because I noticed there are 2 companies that seem to make a lot of the parts for BMW's (MTC, and URO).

I know that in some cases there are aftermarket companies that actually make OEM products for manufactures. For instance, my friend has a Ford Mustang. His fan assembly went out, and when we pulled it out of the car it had "Ford" stamped on it, but it also had the actual maker of the fan assembly as well. He looked up the maker of the assembly and they actually sell the fan assembly for his car, for about half the price. Same exact fan, just doesn't say "FORD" on it. Now, I'm not saying this is the case for anything BMW related, but for $40 instead of $80...I took the risk this one time.

When I recieved the aftermarket tank it looked almost exactly the same. Like surprisingly so. So, I installed it without changing any hoses (which I should've), and started the X up. All three hoses were leaking, and the connections going into the tank. Of course at this point, I'm kicking myself for being cheap, lol. Oh well, I'll just have to order a OEM one. I left it in, b/c the leaks weren't much worse than the original problem, and I work literally 10 miles from the house, so I can just check the coolant level before driving it every time, like I was already doing. After driving it to work and back the next day, I checked the level and it was fine. Hmm....So I started the X, and looked at the tank. NO leaks. I haven't had to add coolant, and the leaks never came back. I'm guessing the old plastic connections had to get hot, and sort of form to the exact shape of the new tank. I'm just guessing though. Either way, it's worked perfectly ever since.

So there's my long story.

Pressure seals the o-rings on the hoses. It's not unusual for those type of fittings to leak a little at first. Silicone grease can be used to help seat/seal the o-rings...

Sent from my iPhone

Um OEM is what you bought. If you want original, it is called OE. I know a lot of people mess that up, adding to more interwebz confusion. My tank lasted 7 years before it cracked. $78 for a new OE one, hopefully another 7 years, 80k miles. Worth it.

Nothing at all leaked on any of my OE hoses and tank when I replaced them all. I did not add any grease.

Did you see post #13?

So you're saying URO is a OEM?

I understand the difference between Original Equipment and Original Equipment Manufacture. That is almost irrelevant unless you're saying URO manufactures parts for BMW.

URO is not a supplier to BMW, they just make the part for the general public. But people interchange it as OEM. SO the way Slick worded it, is right. The part may be build be OE specification, but not quite BMW. I prefer not to use URO. It is a cheap parts manufacturer in CHINA. Their parts don't last very long. You get what you pay for. Just like URO also makes the Power Steering Resevior. It sucks. ZF is the OEM supplier. OE is the ZF housing with a BMW stamp on it.

Well that's what I thought. But if URO is an aftermarket Chinese company, then that's not OEM. It's not original. It's aftermarket made to copy a OE product. How do people "interchange it as OEM"? Either it's OE built by the original manufacturer of the parts, or it isn't.

OEM designates a replacement part made by the manufacturer of the original part.

So no, with respect, the information slick and yourself provided is incorrect.

Well I underatand what you are saying, and you are right. They should not be OEM. But it is used/interchanged all the time. Suppliers like URO, Karlyn, Arnett Beckley, etc are AFTERMARKET suppliers and should not be labeled as OEM. But they do. ECS does it occasionally or they call it a OES (Original Equipment Supplier.) AutohausAZ does it as well. And on the flip side, people call ZF/Lemforder an aftermarket part. But they are a OEM supplier aren't they???? So why call it aftermarket. People just have different wording for things. So what they call OEM, I ask them if its from OEM suppliers. If they mention anyone else, I'll just say, "Ok" for sake of time I don't have time explaining to the 4 or 5 posts a day that ask the same question.

SO I agree, it should not be labeled as OEM, but frequently does. I'd rather not battle it out with those who buy parts and then get lost in wording. I'll recommend to get parts from a dealer and get OE or find who manufactured the part and get it direct from them.

But I agree, URO is Aftermarket.

I agree sir. :thumbup:

I also agree that OE parts (including from the dealer) are the way I would recommend people to go as well.

Yea whatever. I don't keep a list of OE parts, vs OEM, vs aftermarket. Mostly because I don't care to waste my time with what might be an inferior part. I rather spend a bit extra, do it once, use OE, and never worry about it again. My tank failed. I replaced all my hoses, tstat, coolant and all the sensors in the cooling system. It's all about piece of mind for me. If URO is AM, I wouldn't know, all my stuff has the BMW logo.

Yeah it does!!! Lol. My 01 is slowly loosing all of its BMW badging lol. The dealer parts counters by me all price gouge. I have a specialty shop by me and they typically stock all ZF, Mann, Lemforder etc and they have awesome prices. Hell picked up a Mann air filter from then for $12. Dealer wanted $75 lol. Then you found Craig. Now I get all the parts from him for the 4.8. It's 5% more through him on avg but worth the peace of mind IMHO.

Yeah slick, nobody is arguing that buying OE BMW parts isn't the best route. Just remember that your tank, along with countless others, have failed, blew up, etc. You know...the original BMW part.

I'm not following??? It's a wear item with 80k on the clock on it. It's a plastic piece that is subjected to alot of hot and cold cycles. I think that pretty good for a plastic part. If it was a Behr or ZF tank (not sure who makes that) it probably
Would have done the same. Actually he's lucky he got 80 out of it. The 4.4 only got 50 on average. I replaced it twice since I've owned it with 10k on the clock.

Are you trying to say if it was a URo it would last about the same or any aftermarket part?

The only aftermarket on my 4.4 is my front suspension. I went with meyle and my alternator from Pepboys. I went with a Pepboys alt because it gave a lifetime warranty and I couldn't justify paying $800 for a BMW part when I can get one for less with a lifetime warranty.

Oh no, I just meant that even OE parts wear out, fail, break. Quite a bit on the E53 IMO. I have no idea if the quality of this URO will prove to be equal to an OE tank. I guess I'll be the test subject for that. So far at 2k miles, it's been holding on strong, lol.

That's the thing, the part already leaked on assembly for you. I actually would worry about a weak seal when cold. At the same time, the OE didn't leak a drop when I put it on. Also 80k miles later, that ain't bad. Hopefully it passed some BMW standard and that's the quality difference. It's not that OEM or AM won't work, but when something isn't quite right what do you diagnose. Like for example your connections leaked. Is it the old hoses, the brand new tank, or the fact that tank doesn't like the size of the OE hoses? When your hose starts leaking, will you replace hose, or tank? Right, I hope that by choosing OE, I eliminate that guess. Not knocking you, just my logic.

Ttgtr, Twinspappa found Craig. He deserves all the credit. But Craig is great. I mean my OE cost just a bit more then OEM. So no point even considering OEM, let alone aftermarket.

I agree with ya bud!!! I mean you know I changed the front suspension with karlyn and URo only to replace it 4 months later. So yeah they suck. Ended up going meyle and Lemforder. Your
Logic on the tank makes sense as well. You wouldn't know. Am manufactures aren't tight on tolerances. So if the od on the ports are off a few .01 then it
Is going to leak. By the time you fit a new Oe tank, the job would have cost ~$130 instead of $90.

OEM is the way to go on everything on a BMW. Add some "Red Line" to your coolant too, it helps reduce temps, etc. It will take some stress off plastic cooling parts throughout.

Here it is OEM from my key parts source. BMW X5 Coolant Expansion Tank 4.4L,4.6L & 4.8L

Slick, your OE didn't leak a drop, but didn't you replace the hoses at the same time? I wanted to replace my cooling system after reading about it so much on this forum, but this X5 is new to me, and needs a lot. I'm trying to do a little at a time, and also in order of priority.

For the most part, I agree with your logic on the diagnosing of a problem when using an AM tank. Like I was saying in my other post, I was immediately kicking myself for not ordering the OE part. But after 10 miles of driving, I check again and it's not leaking anymore. And hasn't leaked since. So then was it simply the old hoses with "a" new tank? Regardless of the origin of the tank? Seems that way to me. Regardless, I won't be taking the chance on other parts.

I think we're all on the same page, as far as the best choice is going to be OE.


Duke, that is the aftermarket tank that I bought, made by URO. ECSTuning has it for about $45.

And anything you put in there is not going to reduce your temps. The thermostat and DME control coolant temps...

+1. Common misconception. On top of that, water cools better than water with antifreeze. You just can't run it year round, or in a BMW because it needs the special blue sauce.

Either way, nothing will help in these cars. Sensor will say, your temp is too low, lets close the Tstat, and warm this biotch up. Don't waste your money on coolant additives. They are about as useful as nitrogen filled tires.

Yep, that's not a genuine BMW tank it's a Uro LINK

http://c1552172.r72.cf0.rackcdn.com/277538_x300.jpg

Help Me Understand Please
 

About 1 year and a half ago I replaced my ruptured tank with a BMW dealer supplied tank (DIY install). That was at a mere 40 something thousand miles. Just about 10k miles later I'm at it again, but for a slightly different reason. I was checking fluids after changing my oil and noticed the float level was at a wierd angle. Discovered it was broken. Called dealer, "it is still under warranty, so bring it in and we will evaluate and replace if found defective". What I discovered was that the "... bring it in..." meant the vehicle to the service dept. I removed it and brought it in to the parts counter only to be told only the service dept can determine warranty claims. To top it all off, they need to see it in the car? What?

So 2 premature, IMHO, failures of the same OEM item doesnt seem to demonstrate any better quality than aftertermarket. Am I misssing something? Thanks guys.

Bad luck? I donno.

The first failure wasn't due to mileage, it was due to time. May be a hotter ambient that you were running in, perhaps the vehicle didn't always have the proper coolant (just water), don't know. But yes, these tanks can fail. The second failure wasn't the same, it appears to have been a defective assembly, or rough handling. That is what they wanted to see. The OE part had a two year warranty (usually only if the dealer installs it, not for just a parts sale), the aftermarket part wouldn't typically have that warranty. If you want to claim parts warranty, though, you do have to go through the service department as they administer it.

Thanks JCL. I think I would have felt better if I was told it was out of the warranty period. I was actually surprized when they said 2 years. Never seen where the service dept got involved in a parts dept sales ticket.

Is there something to look for to see if the tank or hoses are getting near end of life?

All of my hoses look and feel fine. No cracking, not hard same with the tank. It looks fine. Replacing everything is well over 300 bucks and if needed I'll do it but I'd like to know it is necessary.

Thanks for all the great info here and all over the site.

A hose that is soft is on its way out.

Trouble is, that is a one way test. A soft hose should be replaced, but one that appears fine may go just as quickly.

If you have a slow coolant leak, it is worth tracking it down as it is likely to get worse, not better. Do it at a time and place you choose.

Those that are replacing all hoses and the expansion tank as a preventative maintenance step aren't really doing it because of the hose, per se. It is the same work to do it before or after failure. They are doing it because after a hose goes, if you don't pay attention and know about the potentially expensive consequences of overheating a BMW engine, you can be in for $$$. I haven't replaced my hoses or expansion tank based on time. But I also know that if I run out of coolant, I won't be driving it to the next town to get it fixed the next day. I will be pulling over because I don't want to worry about a warped cylinder head.

When I said not hard I meant as in when they get old and harder than when new like when they get hard and start cracking.

As I have no idea how old they are I am leaning towards peace of mind replacements but I would like to pick my battles and replace the things that make sense.

On a risk vs reward basis this seems like something to do because potentially destroying the motor is $$$$.

Something else to watch for is when those nice black plastic (nylon?) hose ends/quick connects start looking less black and look more brown. My experience has been that the plastic hose ends age faster than the rubber hose itself and become brittle and crumbly, self-destructing on a whim.

But maybe aftermarket hoses have better plastic, and the rubber dies before the ends do? I only have experience with OE. 10 years/100k is what I expect from the hoses, anything longer than that is a bonus, but pushing your luck.

I replaced the radiator this past fall at 130k, planned on replacing all the hoses this spring, but while bleeding out the system, the upper hose disintegrated at the radiator fitting. I replaced the other hoses along with that one.

Couple weeks ago, noticed the expansion tank is starting to form some vapor deposits along the seams...

Coolant Leak, Looks like expansion tank!
 

Hello folks! About a year ago I replaced my expansion tank. It wasn't OE, it was one of the other ones ECS sells. I don't think I got the cheapest one, I am trying to check my order history now. Nonetheless, I have a coolant leak now and based off this pic it looks like the expansion tank. (Should have got Genuine BMW)

http://s15.postimg.org/aau1flisn/coolant.jpg

I added coolant this morning with the heat on 90 deg F, fan low, and bleed screw open. What puzzled me was that nothing came out of the bleed screw. Last time I recall seeing a stream circulate in the expansion tank with the heat on and I would fill until some came out of bleed screw. I added about a quarter gallon and the float was at the max level. I probably added more than I should but nothing came out of the bleed screw! Why is this?

Actually it might have been OE! I ordered it from getbmwparts.com and there is only one option for the reservoir. It was purchased on Aug 2012 for $78.
Does not mention any brand.

getbmwparts is a dealer. BMW of Silver Spring | New BMW dealership in Silver Spring, MD 20904

nothing coming out the bleed screw means there is still air coming out the bleed screw. either park on an incline with the nose uphill while filling, or drive it and check it again after it has cooled down.

I'd contact them about it. Isn't there a 2 year warranty on all factory parts? Also, they have a few parts that if you get them installed at the dealer they have a lifetime warranty...BMW Service : Warranties

I installed it myself. So I don't know about the lifetime warranty. If I do find physical damage, maybe they can replace it.

I checked the coolant again and the float was a little bit lower. But I did see the stream circulating the coolant in the reservoir. I loosened the bleed screw and saw coolant come out. So either a: There was a good bit leaking since 10 AM this morning or b: There was an air pocket that got out, which required more coolant.

I'll check again tomorrow morning. Correct me if I'm wrong, but aren't you supposed to check the coolant when engine is cold i.e. first thing in the morning when engine hasn't been on since the previous day? The second time I checked it was after it cooled down for only 2 hours..

That's usually the best method to make sure it's right. Outside during the winter, 2 hours should be enough (assuming below freezing) though. If allowed to get low, air bubbles do become a nuisance though, and either the incline filling method or driving for a day or two are what's needed to get the last little air pockets out. Or a combo of both.

OP, I feel your pain. I found out 1 week after buying mine hat the tank was leaking. Stealer of course didn't want to fix. $500. :P Will do the thermostat and hoses in the spring, though conventional wisdom says do it all when the tank fails.

Well mine just broke - my son was going to judge a debate meet on Sat. and told me "the check coolant light is on". After he was done I told him to pour some water in the radiator and sure enough, it all ran out. Had it flatbeded to the BMW dealer where he was in South Bend and $596 later, I have a new expansion tank and some sort of trans thermostat that they said usually breaks and needs replacing. No skin off their nose, but another $124 our of my pocket.
I think I might pull a switch and have him drive my 2007 Pontiac Torrent, while I keep the X5 here. I can't fix it if it isn't in my gagage, and the Torrent is scads more reliable than the X.
Bill