The other day, I noticed a small pool on the driveway that would have come from the center toward the front side of the block. Giving it the finger test, it looked like coolant so I checked the reservoir and sure enough, it was down a bit.

I put it up on ramps last night to have a look and it was dripping from the exhaust down pipe. I wasn't able to see where it was originating from because of all the heat shields and what not. It appears that it leaks while the engine is running as I checked the coolant level after it cooled several hours after parking and then again in the morning. It was at a similar level in the morning and since I parked it in a different spot than when I put it on ramps, there was not a pool like there had been previously.

I looked at the Bentley manual cooling section and there was no diagram to give me any indication where this would be coming from. I checked all the hoses, the water pump and the transmission housing below the thermostat and saw no indications of leaking.

Any idea where this may be coming from?

Thanks.

 

You need new seals on the combined oil cooler/oil filter assembly on the front of the engine. A major PITA of a job!


Realoem diagram for a 2007 is: http://www.realoem.com/bmw/enUS/show...diagId=11_3930


Go to the home page and enter the last seven of your VIN to get the diagram for your car. You need items 5 and 6.


Do this repair ASAP!

 

Ugh... bad time for this to go. Graduations, traveling, etc.

Are there any recalls or TSB's on this issue? Any DIY write ups to give me an idea what I'd be facing?

Thanks.

 

first check the coolant feed line to the turbo (goes from oil cooler area up to the turbo). It may be leaking where it's attached to the turbo cooling water pump.

 

One of the toughest coolant leaks to track down is from the oil cooler. We have found coolant and oil leaks in the front of the engine stemming from the oil cooler and oil filter-housing seals. I posted 2 DIY's below for you that will come in handy so that you can confirm if it's in deed your oil cooler. Let me know if you have any questions.

Oil cooler DIY: http://www.pelicanparts.com/techarti..._Replacing.htm
Coolant system leak test DIY: http://www.pelicanparts.com/techarti..._Leak_Test.htm
Parts if needed: http://www.pelicanparts.com/catalog/...pg4.htm#item12

 

^^^ above

 

Thanks for the DIY's, Pelican. Those have been very helpful to get an understanding of what is hidden behind the turbo/heat shields/etc.

From what I've seen, the possible sources of the leaks would require the same parts removed to get access in order to swap whatever component may be causing the leak, is this correct?

 

Happy to help, David. I'm a bit confused by what you're asking. Can you clarify a bit for me? If the cause of the leak is in deed the oil cooler you can just replace the seals. If you do just the seals you can get away doing it without removing the turbocharger. However, you may want to check the condition of the oil cooler because if it is pitted then replacing just the seals wont work. You will need to replace the complete oil cooler. Look at figure 2 in the article for an example.

 

Pelican,

From looking at the DIY's, it seems that all the parts that are the probable culprits are all mounted onto the oil filter housing, ie the oil cooler seals, the oil cooler itself and the aux water pump. It seems to me that you have to take off the same components to get access to whichever one is causing the leak. Is this correct?

Or, if it is, say, coming from the aux water pump, would accessing this not require removing parts that would need to be taken off to get access to the oil cooler?

How would having to replace the cooler require taking off the turbo while just replacing the seals wouldn't?

I just remembered I have a USB inspection camera buried in my garage. I will dig that out and see if I can get a better look with that.

 

1. Not necessarily. The aux water pump can be removed separately. When replacing the heat exchanger, you will be replacing the seals at the filter housing as well. Likely done together.

2. The aux water pump can be removed separately. Without removing turbo, only by placing front end in service position.

3. The turbo blocks access.

 

I got an estimate from the dealership and an indy shop for getting the seals on the oil cooler replaced. The indy came in $400 cheaper than the dealership and will be doing the filter housing seals as well as replacing the turbo oil feed line with an upgraded version. I'm going to let the indy shop take care of it.

I wasn't able to get a really good look with my inspection camera as it had a somewhat floppy cable. I could have rigged something to help it a bit, but time factors made me decide to punt it to the indy.

Thanks for all your help and advice.