QuestionQUESTION: Hi Todd
I have a 1990 Grand Prix LE with a 3.1 L engine.The problem is very little or no heat at all. The radiator fluid is full, checked it within a 2 week period to check for any variation. The thermostat has been replaced twice, second time with fail safe thermostat,still no change. The temperature gauge tends to move up and down when I turn the blower from slow to max.with heat on high still luke warm to no heat.I hope this gives you enough information. We just had a major snow storm and I need heat. Hope you can help me.
.........................................Thanks Mike
ANSWER: Hey Mike.
A few ideas. the heater core could be bound up woth an air pocket. Let the engine get hot and see if the hoses get warm. if so you have flow through the core. if not then the core is plugged or it's bound up with air. If they get warm or hot then you have an air delivery issue inside the car maybe the temp door is stuck or binding up not allowing air to flow past the heater core. Good luck :)
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QUESTION: Hi Todd
Thanks for the advice. Top hose is hot, bottom hose warm. How do I properly bleed the air out of the coolant system. I found the bleeder screw. Do I have the coolant at operating temperature, car running then open bleeder? For how long? ....Thanks Mike
ANSWER: Hi mike:
If you have one hose hot and one warm you more than likely don't have an air pocket the difference in temps is because the heater core was disipating the heat into the heater box much like the radaitor does for the engine. You could have a restriction in the core take off both hoses and run a garden hose in both directions through the core and take note if any crud comes out of the core. put them back on and run the car open the bleeder up when the engine is hot and only untill it expels any air if you get a steady streem of coolant then you got the air out. If that doesn't help then you have some sort of an air flow/door issue inside the HVAC box in the car.
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QUESTION: Hi Todd
Merry Christmas! I have flushed out the heater core, still no difference. But I did have a small exhaust leak in a pipe,so I put car up on ramps, repaired the small hole. I decided to bleed the cooling system one more time, I kept checking the temp. gauge and the engine rose to operating temp. which it wasn't doing before and stayed there until I pulled the car off the ramps and let car run then,temp. gauge came down and cool air started coming out again with heat on high. Rad cap has also been replaced. Do you think it could be a leaking head gasket as I believe it is leaking because little oil is on engine block. My oil level also goes down but not rad fluid.If it is the head gasket do you recommend Thermaweld or Steelseal for leaking head gaskets.The car is in good shape and I don't want to scrap it.It has been a good comuter with 156 000 KM.
..........................Thank Mike
AnswerI really do suspect a head gasket on this but you don't know unless you do both a coolant pressure test and a cyclinder leak down test and I'm sure you don't have either of these special tools. You may want to try one of those products It's a crap shoot as to wether they work or not. Bars all has one to and there is one other product on the market but the name escapes me it's a guarnateed head gasket or cracked block fix product. I don't recomend using any of these but id money is tight and at the holidays it is or if the car has a lot of miles like this one does it may be worth a try. Just follor the directions to the "T" no short cuts if it says the car has to sit 12-24 hours after adding the product do it. Good luck.
