loosing coolant somewhere.

[scott540]

week and a half ago the coolant message came on. I topped it off with about a quart of coolant. Today the message came on again when I shut the car off after driving about 25 miles. Total driving was about 50 miles from when I topped it off. No drips in the garage and I cant find anything wet or dried spots. Any ideas?

[632 Regal]

look behind the intake, and or under where the coolant tubes connect under the intake. hidden...out of site out of mind.

[andyman32]

Haha... yeah, Scott, there are lots of great places on our cars where coolant can leak without being seen. I just replaced my water pump and radiator hoses, but I accidentally unseated one of the coolant tubes that runs under the intake. I sorta "felt" it back in at the rear, not wanting to remove the intake, but now I still have a slow coolant leak - and I know EXACTLY where it is. It's at the back end of that pipe.

Here's the ETK diagrams of the cooling system:

http://rust.mine.nu/bmw/partgrp.do?model=HE63&mospid=45173&prod=19931000&hg=17&fg=05

http://rust.mine.nu/bmw/partgrp.do?model=HE63&mospid=45173&prod=19931000&hg=11&fg=35

On this 2nd page, the pipes we're referring to are #4 and #6 on the "Cooling System Pipe" diagram.

[tim]

You might want to check out this thread wherein Jeff spotted my problem. Since you have a manual tranny, you wont have the exact issue, but the heater core inlet and outlet pipes are in the same location and just as prone to leaking. Prehaps the reason why you're not leaving puddles is that anything that drips from here lands on the header pipes and burns/evaporates.

http://www.bimmer.info/forum/showthread.php?t=7276

The other issue I've had that sounds similar is that the rad can get a fine crack, that only loses coolant under pressure.