difficult find

[JTis]

Originally Posted by flyingmachine

all transmissions need cooler. it's in the same location on 4.4 and 4.6(M62 engine). It's on the driver side on 4.8(N62) which is similar to 3.0 design.

JTis, how did you find the leak from there. It's pretty deceiving location as most people would think radiator is punctured or it leaks from the thermostat right above the heat exchanger.

Sorry---poor phrasing on my part----I was just thinking that the 3.0 and 4.4 didn't have the separate "snap on" exchanger. I got lucky on finding mine....took the undertray off, and after about 5 minutes of looking with a flashlight, noticed the blue crusty buildup around the plastic attachment points. Very easy repair---the hardest part was getting the old o-rings off.

[Weasel]

Originally Posted by 645i

Well after the fluid hits the ground and evaporates it does not leave a ground stain like coolant normally would. so this sounds like a washer fluid like. But I still don't know why my coolant level goes down when i dont have a leak could it be that I did not put enough coolant in when I replaced the resevoir? any suggestions?

I'd check the bottom of the washer pump motor for leaks. It is pretty easy to remove the 1 10mm bolt that holds the bottle in place and pull it up for a better look.

[ahadi]

Hi Guys,

I have same issue with my heat exchanger, it leaks between those 2 O-ring. Do I need to flush the coolant system in order to replace the O-rings?

[flyingmachine]

Originally Posted by ahadi

Hi Guys,

I have same issue with my heat exchanger, it leaks between those 2 O-ring. Do I need to flush the coolant system in order to replace the O-rings?

there is really no flush required. just "drain". yes, you must drain coolant before pulling the heat exchanger off.

it's recommended to drain and refill coolant every 4 years anyways. don't forget the drain plug on engine block.