Overheating and blowing cold air [Archive] - GrandAmGT.com Forum


View Full Version : Overheating and blowing cold air

12-27-2004, 07:59 PM
First off, thanks for taking the time to read (and hopefully respond) to this. I will try to be as informative as I can to ensure the entire situation is outlined.

I have a '99 GA SE2 3.4L. It has ~70k miles on it, and just a few thousand miles ago we had the intake gasket replaced, as well as the water pump, radiator, coolant reservoir cap 2x, and I just replaced the 2 main radiator hoses and tstat yesterday.

Gradually the car began to overheat more often and lose coolant often - thus the replacement of parts one after another hoping to tackle the problems. I did notice just before I began replacing this stuff, back when the LIM was leaking and I had to add coolant, that there was some sludge/gunk in the coolant reservoir - it was oragnish brown. Since I have replaced parts listed above, and obviously filled the system with dexcool again, I haven't really seen any sludge, but I'm afraid that it may be stuck in another part of the cooling system - such as the heater core?

When filling the cooling system, I usually open the valve above the waterpump and wait till coolant/water begins running out of it and then close it. That usally gives me the warm fuzzy that most of the air, if any, is not trapped in there and was "pushed out." Then after the car is warm, and the tstat is open, I turn on the heater full blast and bleed/burp the system again using that same valve above the waterpump. Once I see a solid stream of coolant, I will rev it up a little bit, wait 10-20 seconds, rev it up again, wait 10-20 seconds, open the valve again. If any air came out the last try, repeat.

Things I have done:
-Replaced the LIM gasket
-Replaced the water pump
-Replaced the Tstat
-Replaced the serpentine belt
-Replaced the 2 main radiator hoses
-Checked main system parts for leaks
-Checked the passenger floorboard for leaks/moisture
-Burped the system the best I know how

Things I have not done -
-Properly flush/reverse flush the system with a chemical solution such as prestone (this is next on my list - hoping the heater core is clogged)
-Checked to see if the outside air inlet is working properly (no clue how yet)
-Something else that I am not aware of :)

Things I have noticed most recently (4 trips since I changed the stat):
-After a cold startup, the car will still overheat. I turn it off, wait a few mins, turn it on, and then the tstat will kick in shortly after and the temp will go to normal.
-There is a slight hissing sound coming from the reservoir tank, it could possibly be the cap. So it's on my list to buy another one.
-Burping the system is messy
-Dexcool doesn't taste good

So in summary, even after replacing the above items, and burping the system the best I know how, the car still overheats, and hot air rarely comes out.

Thanks in advance for any help you can provide.

PS: what's the best/cheapest place to buy a new coolant reservoir tank? Someone (possibly me but I 'm usually good with that stuff) crossthreaded the first thread or two pretty bad that it takes me a few times when putting the cap back on to ensure it's not crossthreading again.