[Cuda021312]

Any input would be greatly appreciated. I purchased a Vemo thermostat from ECS Tuning and installed it with no problems. I replaced the original due to the valve not opening and closing properly. I had zero leaks with the original but now both push connectors that attach to the thermostat are leaking coolant. I then replaced the o rings in the connectors in hopes that they were the culprits but still leaking. I then replaced both hoses thinking that the connectors on the original hoses would no longer hold a true seal but still leaking. I made certain the connectors were on correctly. Is it possible that the new Vemo thermostat is the problem? Has anyone had a similar problem with a brand new replacement thermostat? I'm going to reinstall the old thermostat to see if the leaks persist. Thx

[BKV122]

Very possible it is the new thermostat. Especially afyer trying new hoses and O rings.

[Cuda021312]

Originally Posted by BKV122

Very possible it is the new thermostat. Especially afyer trying new hoses and O rings.

UPDATE...

The new Vemo thermostat was the culprit. I installed the old genuine thermostat and no leaks whatsoever. I may have found the cause of the valve not opening and closing properly. At some point a piece of hose had broken off somewhere and made its way inside the thermostat. It lodged against the valve, completely disabling it. It appears to have been in there for quite sometime as it has badly deteriorated.

[Ozzie335i]

Not a knock, but why didn't you proactively replace the water pump while you were at it?

[Cuda021312]

Originally Posted by Ozzie335i

Not a knock, but why didn't you proactively replace the water pump while you were at it?

Not a knock at all and thanks for the feedback! I had already replaced the water pump last summer. Upon doing so, I found a quick and painless way of removing the thermostat without having to remove the fan shroud so I wasn't worried about having to do the thermostat when need be.

[TenOx]

Originally Posted by Cuda021312

Not a knock at all and thanks for the feedback! I had already replaced the water pump last summer. Upon doing so, I found a quick and painless way of removing the thermostat without having to remove the fan shroud so I wasn't worried about having to do the thermostat when need be.

Would you mind sharing the quick and painless way of replacing the thermostat?

I was looking at the job and the one series of steps I see requires removing the cooling fan and housing, intercooler, dropping a tube or two (P/S cooling hoses +/or cross-compartment radiator tube)
and some directions specify dropping a stabilizer bar.

That is a lot to just access and replace only the thermostat in 2007 E90 (335i) N54-motor Bimmer sedan! It would be great to find a quick and painless way.

Thanks.

[mweisdorfer]

Originally Posted by TenOx

Would you mind sharing the quick and painless way of replacing the thermostat?

I was looking at the job and the one series of steps I see requires removing the cooling fan and housing, intercooler, dropping a tube or two (P/S cooling hoses +/or cross-compartment radiator tube)
and some directions specify dropping a stabilizer bar.

That is a lot to just access and replace only the thermostat in 2007 E90 (335i) N54-motor Bimmer sedan! It would be great to find a quick and painless way.

Thanks.

You will need to take the fan out, drop the FMIC & move the steering rack out of the way, in order to get to the thermostat.

Typically speaking, the water pump & thermostat are replaced at the same time along with the U shaped pipe that connects the two, about every 75,000 miles, if you are being proactive.

Otherwise, it is best to have at least a $100.00 bill stored in your glove box for the tow truck and then accept paying premium prices on both parts plus overnight shipping costs....