cjmatt

iTrader: (4)

hey guys, ive got a 98 trans am that running between the middle andred zone, im guessing 235 degrees. i know its hotter then normal, and it also takes a while to warm up, but once its warm, itll stay at 210 for a while then creep up as i drive. what do you think could be causing it? i checked the coolant and it is at a good level also

98sskidd

iTrader: (1)

stuck thermostat possibly. change it and see if that helps.

BLKWS.6

^ +1

That is where I would start.

RPM WS6

iTrader: (3)

Good possibility.

But first verify that the fans are cutting on.

cjmatt

iTrader: (4)

also, when i was topping off th radiator, i ran it with the cap off and restarted it around 160 im guessing at which point the coolant was dead still in the radiator. at one point it all started pouring out so i shut the car off and it was just over 210. ive just never seen the coolant overflow like that, im guessing it probably puked out 2 liters worth

Emerald Phoenix

iTrader: (2)

Coolant still expands with heat. I don't know how much, but it doesn't sound unusual. Add another vote for the thermostat.

angel71rs

I had something similar happen to my SS once. Warmed up normally, but then the temp kept climbing till it was getting near the red zone. Turned out it had hoovered up a piece of plastic somewhere and it was blocking off part of my radiator.

98sskidd

iTrader: (1)

Since ur already gunna replace the thermostat might as well flush out the system too. Make shure everything that in there gets out. Prestone makes that coolant flush, ive used it and it actually didnt do to bad in there. My 98 ss actually ran a little bit cooler after i flushed it.

ls1_doc

iTrader: (6)

I dont think its a stuck thermostat. A bad thermostat generally causes you to overheat very quickly. More than likely with the symptoms you have its either a plugged radiator or a water pump starting to fail. Worse case scenerio is a combustion leak such as a blown head gasket. But maybe a thermostat will help. Its really hard to diagnose without actually seeing the car.

cjmatt

iTrader: (4)

i dont think its a combustion leak as it doesnt burn any coolant and there is no blowby at all, the car runs rally strong. ill check the radiator for debris, i cant believe i never thought of that

cjmatt

iTrader: (4)

well i just got under it and the radiator is free of any debris, so i guess im gonna start with a thermostat, then a waterpump if that doesnt work. is there a draincock on the radiator? id look but weve got an inch of snow on the ground

WS6 Rampage

iTrader: (3)

I'd say thermostat but your say'n that it stays at 210 for awhile THEN jumps up a short time later. You might wanna check your fans bro and see if they're take'n a **** on you!

Try romp'n on the throttle once she's warmed up. When the temp creeps up pop the hood. Check out the fans,.....see if they're work'n properly! I dunno,....my thoughts are that one of your fans might be take'n a crap when the temps get high enough. What does everyone else think?....

'Trust'

iTrader: (24)

Draincock is at the bottom on the passenger side of the radiator, you can't miss it. I'd try running your car without the cap on again and make sure there are no bubbles in the coolant, then check fans, then check the thermo.

ls1_doc

iTrader: (6)

No no I think your radiator is plugged inside. The syptoms you are having point to that or possibly a waterpump. I really doubt its heads either.

RPM WS6

iTrader: (3)

As I mentioned above, before you start replacing parts, make sure the fans are cutting on.

cjmatt

iTrader: (4)

well the thing is that it runs hot on the freeway too when im going like 80 which is like 2800 rpms with my 3.73s and auto. but 80 mph should be planty to keep it cool

ls1_doc

iTrader: (6)

Yeah the fans should not be a real issue here. Although make sure you have the plastic air dam on the bottom of the car.

MontyinArlingtonVirg

Had the same problem with my 1998 z28. One day began running hotter than normal, but not overheating. I did not suspect my thermostat because they usually fail either dead open or dead closed. But, wtf, I put in a new one, and problem solved.

Monty

Ntimid8r7

iTrader: (9)

One other thing that hasnt been mentioned, you might want to start cheap and replace the radiator cap. If it doesnt keep the proper pressure it could cause it to run hot as well. I had this problem a few months ago and spent $6, no heating issues.