Coolant Leak...

null_q

New Member
Aug 6, 2005
15
0
0
Denver, CO
So I am slowly losing coolant, and it has been boiling out of the overflow reservoir as I drive. I cannot figure out what has been causing this. I took it to a mechanic and he replaced the radiator cap, and this worked for a couple of months, but I started losing coolant again recently out of the reservoir.

I also get really bad fogging on the windshield inside the car, and it's very greasy/oily. I keep cleaning it, and the fog keeps appearing. Ocassionally, I can also smell coolant inside the car, and it is very obvious that it is coolant.

I assumed my heater core was leaking so I took it out, but found no major signs of leaking, in or around the heater box.

So I am pretty stuck, any suggestions?
 

johnathan1

Supra =
Aug 19, 2005
5,056
1
36
36
Downey, California, United States
wow, that's weird... Is there still weatherstripping under the hood, at the base of the windshield?

Pressure test the cooling system, and check for leaks, @ 20psi, most leaks become pretty obvious. Also, is there any white smoke coming out of the exhaust?
 

null_q

New Member
Aug 6, 2005
15
0
0
Denver, CO
There is weatherstripping at the base of the windshield, And I do get puffs of smoke on startup after the car has sat for ahwile.

I guessed BHG after it started overflowing again, but I did a block test and found no sign of combustion gasses in the coolant. I'm not sure if that would completely rule out a BHG or not though.

Thanks a lot for your replies.

Oh and the mechanic pressure tested it when he had the car and found no leaks, this was a couple of months ago.
 

supramacist

Banned
Apr 8, 2006
1,501
0
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The Grassy Knole
I was about to say heater core, but I have never had one of those go oily. I had an 89 ford taurus sho that I replaced the HC, it went out again and I bypassed it. It'll still blow warm air in the winter. Well...., warmer than outside, hahahahaha