[sweety59]

Hey Guys. My Coolant Expansion Tank just cracked on my 07 335I. The dealer quoted me a ridiculous price of $178 for the tank alone. I was hoping to find an aftermarket one online, to save some money. After all, it's just a Coolant Reservoir Tank, right? I did hear that they were pressurized. Either way, I don't wanna half-ass the job. But if an aftermarket tank for the fraction of the cost will work just as well, I'd much rather do that.

Thoughts and opinions? Car is currently down, since it won't hold much coolant. Need to get one ordered ASAP!

Found this one online. Thoughts?

http://www.partsgeek.com/catalog/200...sion_tank.html

[cahme]

I just replaced mine today after the old one started leaking at the seam Wednesday. I ended up getting one at a local dealer (who had 8 in stock) for $125 so I could fix it this weekend. When I bought this car 6 mo ago, I accepted that the parts would be high and the online places didn't offer much of a discount.

If I'd have ordered it, I'd have gone with FCP Euro as they have a lifetime warranty on all the parts they sell and this seems to be a common problem. Mine failed at just shy of 6 years old and 120k miles.


Edited to add .. sorry, I didn't check your link before. If your going to order anyway, I'd be fine with the Bilstien one. For my '11, there is no options other than BMW from my quick search.

[Rickygst]

Look at ECS Tuning, they have several options. I think I got a behr and you should be fine with a OEM unit

[Rocko123]

Id just worry about aftermarket parts fitment and build quality but if your getting the part from a reputable place that backs up their parts with that good of warranty id assume its good to go..

[sweety59]

Thanks for the input guys!

I think I'm gonna pull the trigger on the Bilstein one, which is actually Febi. It's $60 shipped, with a 1-year warranty. Beats the $125 the dealer wants to charge me. I'll let you guys know how the quality and fitment are when I receive it! Should be a pretty straight forward swap.

[fatjoez]

BMW Expansion Tank - Behr 17137640514
https://www.fcpeuro.com/products/bmw...nk-17137640514

Also had this replaced last year due to crack

[sweety59]

Originally Posted by fatjoez

BMW Expansion Tank - Behr 17137640514
https://www.fcpeuro.com/products/bmw...nk-17137640514

Also had this replaced last year due to crack

Thanks for the link! $10 bucks cheaper than what I've found! I'm assuming cracking is a common problem with these things?

[BashShah]

Originally Posted by sweety59

Thanks for the link! $10 bucks cheaper than what I've found! I'm assuming cracking is a common problem with these things?

BEHR, with a Hamman Level Sensor $44 eBay.

[BruceJ]

Originally Posted by sweety59

Thanks for the link! $10 bucks cheaper than what I've found! I'm assuming cracking is a common problem with these things?

Cracking expansion tank is like a BMW engineering must have. It's been a known and obviously an accepted/ignored flaw in their cooling design since mid nineties. I think they keep it so they can point out the inherent engineered planned obsolescence to new engineers! Their next and not so effective stab was the electronic dipstick. BMW engineering is a love have thing. They are always increasing the odds that the high performing, truly innovative engine designs will prematurely destruct for the most absurd reasons!
Rant over
I love the car for its performance, looks, and the envelope pushing but the stupid stuff makes me crazy. LOL

[Efthreeoh]

Originally Posted by BruceJ

Cracking expansion tank is like a BMW engineering must have. It's been a known and obviously an accepted/ignored flaw in their cooling design since mid nineties. I think they keep it so they can point out the inherent engineered planned obsolescence to new engineers! Their next and not so effective stab was the electronic dipstick. BMW engineering is a love have thing. They are always increasing the odds that the high performing, truly innovative engine designs will prematurely destruct for the most absurd reasons!
Rant over
I love the car for its performance, looks, and the envelope pushing but the stupid stuff makes me crazy. LOL

I'd go with the design being okay. The issue is more a manufacturing defect where the tank halves are not properly sonicly welded correctly. Perhaps it is BMW supply chain that beats on it's suppliers for less and less expensive parts.

And it really isn't an expansion tank, but rather a coolant reservoir and part of the radiator, which is why it is pressurized. This design allows BMW to fit various radiator designs applicable to the various different engines/tranmissions used in the E9X chassis while keeping the reservoir tank design constant through out the E9X 3-series. It lowers the cost of the radiators and lowers the cost of the tank.

Nonetheless, it should be a lifetime part.

[BruceJ]

Originally Posted by Efthreeoh

I'd go with the design being okay. The issue is more a manufacturing defect where the tank halves are not properly sonicly welded correctly.

while I have the same love for the car that many of us do I have to respectfully disagree. This has been a problem across car lines and the lack of a fix makes it a $50 part that can take out a $12-15K engine. Ignoring this type of vulnerability is a matter of policy controlled by the mfr.

Other examples include:
Electronic dipstick - Since the N52 and pretty much in all current engines- surprise, there are now reports of the sensor failing. So why would a mfr deliberately put in a part that replaces a failsafe indicator when what it indicates is so critical?

N54 serpentine belt/pulley- No other car mfr has a serpentine belt where failure can literally destroy an engine. Its not a timing belt here and its an external belt. See post #6 in the link below
http://www.bimmerfest.com/forums/sho...d.php?t=709943

So why is it that its failure, taking out the engine has not been remedied? At some point BMW should take responsibility for its mistakes - They cant, because its a culture of ego instead of responsibility. Oh, the BMW fix is buy a new car with a N55 engine. What surprises will it bring?

[Efthreeoh]

Originally Posted by BruceJ

while I have the same love for the car that many of us do I have to respectfully disagree. This has been a problem across car lines and the lack of a fix makes it a $50 part that can take out a $12-15K engine. Ignoring this type of vulnerability is a matter of policy controlled by the mfr.

Other examples include:
Electronic dipstick - Since the N52 and pretty much in all current engines- surprise, there are now reports of the sensor failing. So why would a mfr deliberately put in a part that replaces a failsafe indicator when what it indicates is so critical?

N54 serpentine belt/pulley- No other car mfr has a serpentine belt where failure can literally destroy an engine. Its not a timing belt here and its an external belt. See post #6 in the link below
http://www.bimmerfest.com/forums/sho...d.php?t=709943

So why is it that its failure, taking out the engine has not been remedied? At some point BMW should take responsibility for its mistakes - They cant, because its a culture of ego instead of responsibility. Oh, the BMW fix is buy a new car with a N55 engine. What surprises will it bring?

While I'd prefer having a mechanical dipstick on the N52, I've managed to somehow get to almost 300,000 miles without one. The issue people around here have is they think by pulling a dipstick and checking the oil level makes them a car enthusiast, so their ego is a bit dented when they can't on the N52. The issue with a mechanical dipstick is the operator HAS TO USE IT, so it's not really fail safe at all. In fact having a low oil level warning is more fail safe than a mechanical dipstick because it is a non-participating sensor. The majority of BMW owners don't even know what a dipstick is or how to properly use it, so a warning notification is actually better for today's car owner.

I don't see how a failing coolant tank can cause an engine failure. It appears the tank develops a leak, that gets first noticed as a low coolant notification. So an attentive operator, not ignoring the notification, has time to get the vehicle repaired.

With the belt, the rare occasion one fails and possibly gets into the front crank seal, is really not the level of a recall as the airbag issue is.