Around 2 years back when I had a slow coolant leak and after reading about the horror stories about rad failures I decided to change a lot of cooling components. Basically I changed everything(yes everything) except the heater core. I even had a pressure test done and the local indie said I was good to go. But I still have a leak, very slow. Over a period of 6 months or more I see the coolant level go from max to somewhere just above min. My question is am I in for a heater core replacement ? I do remember(2 yrs back) that once or twice I have had this white vapours coming out of the A/C vents. But this has happened only those 2 times. I dont smell anything inside the car and the windows dont mist up. What should I look for ?

Thanks
Naveen 92 940T@135K 00 9-3SE@54K

Hi: I had the exact problem in my 91-940se T wgn. Pressure testing the system it held 17-18 psi for 30 min +. I pumped it to 20 psi to start.


The problem was the heater core. At operating temperature the leak would open enough to cause fogging on the windshield. The heat could be full blast, defrost & the misting was still there. No real smell of antifreeze.

I changed the core (15hrs)& the problem is gone. The old core was very clean w/ very small amount of whiteish deposits (usually seen at a coolant leak site). If the car was only driven by me I would do what Steve suggested )small amt. of leakstop). But it's the wife's so I changed it.

The bonus is I now know how damn near the entire dash comes apart.

ibs740

If you replaced heater hoses to core do not jump to replace core untill you are sure it is bad, and listening to this. I had a leak and coolant in cabin floor but good info here saved me! Seaking core info a brickboarder replyed (wish I could remember his name to thak him) here and told me strange story (I thought) that end up true and saving my ass. What happened to him and myself is when we replaced the heater hoses we damaged the surface of the core nipples with maybe a razor knife (cutting old ones) or screw driver when prying off old(gouge). The new hose was pushed up tight against the fire wall that has a opening around the nipple filled with a rubber porus sponge matterial. Our leaks where from outside surface of the core nipple surface not the core itself! I checked his info and pressure tested my core before pulling it and it held pressure! so I sanded/cleaned nipples and reinstalled hoses properly sealed the second time and my leak/problem was cured one year ago.

Good Luck Buddy,
"Park"

I would ignore it, with one exception: put a small amount of "stop leak" in the reservoir. Yep, you read that right. Many auto manufacturers do that to eliminate warranty claims and loss-of-coolant situations. It does work to seal small leaks and keep you on the road. Don't use a whole bottle: just about a third to a half works well and won't promote corrosion.
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