Coolant Leak - I'm Lost!
 

Hello all!
My R55 finally threw its first fit with me, I initially thought my water pump went out as I've been having a slow leak lately. My friend and I replaced it today, everything buttoned up nice and tightly. We go to fill it with coolant, and it still drips!! :confused:

What else could be causing the leak? It is coming from the left side of the car (from a top-down view) for sure. Thank you all in advance!

The thermostat housing is plastic and a common failure. It cracks along a seam. Here is a picture of one off of the car and a picture of where mine cracked. It was a slow leak that dripped down on top of the transmission. Check all of the coolant lines connected to the housing. There are several. Check the coolant lines in and out of the oil filter housing mounted on the front of the block behind the turbo. You may need to look from underneath.

I will most certainly check that out, I have to get it off anywho, I have a hunch that the water pipe could be the culprit. But it can't hurt to look at the thermostat while its off. Thank you!

Yes, the thermostat can be a problem unfortunately. They tend to get a hairline crack and so it can sometimes be hard to see. We have thermostats here in stock and ready to go if needed. Yes, check out the water pipe as it is also plastic and has been known to leak. Here if needed. When disconnecting, be sure to remove the clip on the thermostat side, #3 below.

https://cimg1.ibsrv.net/gimg/www.nor...13e2f30982.png

Yep most of the time its the thermostat housing dripping on the transmission and pooling. Here is a link to the DIY and other parts to check and replace while you have the cooling system open. Let me know if you need anything because I did all the work myself and know more of the tricks an tips. :thumbsup:

https://www.northamericanmotoring.co...8-no-heat.html

11537534521 KT


https://cimg8.ibsrv.net/gimg/www.nor...f13c193b70.jpg

I did mine too and ECS sent me one of their Thermostat housings for a little cash.

Thanks :)

Update! Haha good and bad!

Turned out to be the water pipe, the end connecting to the block had disintegrated (shoutout to BMW for making pipes out of plastic!).

Everything seemed to be ok until this morning, and now a new drip has formed! This time is seems to be on the side closest to the thermostat. Its not alarming, but enough to cause concern.

I'll do a tear down this evening when I get off work and report back!

Thanks for all your comments so far!

You are welcome. :thumbsup:

Let me know if you need anything. Make sure the connection from the thermostat to the water pipe is secure and the gasket on the thermostat to the pipe is all the way in and the clip is in.

What'd you find out?