Gator Angler

Same thing happened here in my 05 545i at 80k. My wife never drives my car and it happened while she was driving. She of course keeps driving after the the coolant tank busts until the car turns on full heat (this was in June in Florida) wife keeps driving and eventually it shut itself down. About 6 weeks later as part of a regular service BMW replaced every hose in the car -- I believe as a result of how hot it got when the coolant tank blew.

Dutch 530i

I just got my car back today after some mysterious coolant leaks and it was the thermostat leaking and the expansion tank too!, plus I replaced the whole network of hoses to make doubly sure it shouldn't do it again.
Not great for such an expensive brand.

Howitzer

What is the cost to pre-emptively replace the expansion tank? I mean, if this is BOUND TO HAPPEN, I might as well just do it now and save myself the grief of being stranded.

luigi524td

Cooling system plastic part failures have been a BMW pain point for more than a decade. Some SA's have gone so far as to say that preventative maintenance should include replacement of all plastic cooling system components should be scheduled every 50K miles.

No doubt BMW is aware of the weak points - all they have to do is study the replacement parts reports.

About 10 years ago [after replacing the THIRD coolant recovery tank on my e32 740i] I quizzed a BMWNA rep about the predictable failure rate ... the response was that increased use of plastics and light metals is to reduce vehicle weight .

I suggested they consider sourcing the parts from Nissan

porsche911targa

Expansion tanks should be the weakest point in the E60. I will replace mine preemptively at 60K. The radiator should be OK now that it's aluminum.

kpatter

I have been researching prices for expansion tanks today. I drove to BMW of Dallas and was quoted 110.00 but found them on-line for 80.00. They look fairly simple to replace and would love to see a DIY. I have a 2004 with 52K, I have replaced my thermostat and waterpump as preventative maintenance in the last month or so. I am nervous about the expansion tank blowing.

vlad_b

"Expansion tanks should be the weakest point in the E60. I will replace mine preemptively at 60K. The radiator should be OK now that it's aluminum"

hope so. most of the time after one thing goes down (expansion tank) other cooling parts follow. hope the radiator is ok, since i stopped right after this breakdown occurred

tallers

My expansion tank was replaced last week, 04 545i with 120K miles. I took it in to BMW when I noticed a coolant leak and they first replaced a coolant vent pipe and a coolant temperature sensor at the tune of $900, which included a coolant flush and replace. I noticed a coolant leak afterwards and brought the car back and stated I was NOT happy. They then discovered the expansion tank leak and replaced it, no fee.

vlad_b

good that you discovered leak soon. and it's nice to see a 545i that has 120K. How is it, any major issues apart from this one?

pinguhk

sorry to hear this
this is common.
In HK we have members change this too.
I think the plastic that they made them out off is not 100% up to the heat.