Losing coolant

[PatrickinWA]

1997 Bravada 4.3 ~ Dexcool-3 Me-0
My coolant looked like mud when I first got the truck a year ago. Flushed her out 3 times myself before I took it to the mechanic who charged me $90.00 and told me I needed a new radiator and water pump, $692.98 was the quote. I replaced radiator, pump, upper/lower hose, heater core hoses, and thermostat. Only took about three hours and total cost was under $200.00. Truck ran great for about two months. Since it has gotten cold here in WA, I have a new problems. Here is my list of symptoms:
1) Coolant Loss - About a gallon per week, nothing under the truck.
2) A slight mist of coolant,(like you would see if you had a pin hole in a hose) appears from under the hood when I turn off vehicle. Pop the hood and there is nothing, just looks like the windshield above the heater core is steaming.
3) Slight smell of exhaust in the cab
4) slight smell of antifreeze in the cab
5) Small decline in fuel economy
6) Very slight but noticable erradic idle at a stop light, doesnt happen if the truck is in neutral or park.
I am thinking the steam could be coming from the heater core, but I am not getting any other symptoms of it going bad. Carpet is dry, windows arent fogging up, getting great heat. I am wondering if I have gasket issues? If so, which one/ones could they be? There is no coolant or water apparent in my oil, (changed oil 2 days ago and let the old stuff sit in the pan for a while so I could check).

[MT-2500]

Originally Posted by PatrickinWA

1997 Bravada 4.3 ~ Dexcool-3 Me-0
My coolant looked like mud when I first got the truck a year ago. Flushed her out 3 times myself before I took it to the mechanic who charged me $90.00 and told me I needed a new radiator and water pump, $692.98 was the quote. I replaced radiator, pump, upper/lower hose, heater core hoses, and thermostat. Only took about three hours and total cost was under $200.00. Truck ran great for about two months. Since it has gotten cold here in WA, I have a new problems. Here is my list of symptoms:
1) Coolant Loss - About a gallon per week, nothing under the truck.
2) A slight mist of coolant,(like you would see if you had a pin hole in a hose) appears from under the hood when I turn off vehicle. Pop the hood and there is nothing, just looks like the windshield above the heater core is steaming.
3) Slight smell of exhaust in the cab
4) slight smell of antifreeze in the cab
5) Small decline in fuel economy
6) Very slight but noticable erradic idle at a stop light, doesnt happen if the truck is in neutral or park.
I am thinking the steam could be coming from the heater core, but I am not getting any other symptoms of it going bad. Carpet is dry, windows arent fogging up, getting great heat. I am wondering if I have gasket issues? If so, which one/ones could they be? There is no coolant or water apparent in my oil, (changed oil 2 days ago and let the old stuff sit in the pan for a while so I could check).

If there is a mist/spray of coolant there is a leak.
Flollow that spray/mist backwards and it will lead you to the leak.

Somtimes a rad pressure tester will help find te leak and always check cold warm and hot.

PS.
Winter driving and warm ups and winter gas can lead to lower gas mileage in cold weather.

[chobes]

How many miles? I would do a coolant system pressure check. Could be you head gasket as well. if not a head gasket at least you can pressurize the system and it may help you find where your small leak is coming from.

[TooHipCat]

I've heard that if you use a blacklight...when it's dark of course...you can pick up the irradescent color of the coolant. This may help you pinpoint the exact location of the leak.

Good luck!

[MT-2500]

Originally Posted by TooHipCat

I've heard that if you use a blacklight...when it's dark of course...you can pick up the irradescent color of the coolant. This may help you pinpoint the exact location of the leak.

Good luck!

They make leak dye test fluid to add to coolant for the light test.

[Rick Norwood]

Go to Autozone and borrow the radiator pressure tester. It is a small hand held tire pump with a radiator cap and a gauge on it. When your engine is cool and turned off, remove your rad cap, make sure your rad is full, attach the cap from the tester, and pump the pump up to the pressure rating of the cap, usually 15 pounds or so. You should have a flash light handy but your leak should become visible.

This check is fast, easy and FREEEEEEEEEEEEEE.