I have 96 Sunfire with a 2.2L. My car seems to warm up fine in city driving but as soon as I get on the highway my temp guage goes way down and cold air comes out of the vents. The waterpump and thermostat are brand new. What is wrong?? I need heat as I am freezing. I have heard on this forum that anything other than AC Delco thermostats have a weak spring causing the coolant to flow through and not let the engine warm up at higher speeds, is this true?? Also when it is warmer out my temp guage runs to the upper side of the normal guage (a little further then I would like), is this normal. The thing I am most concerned with is heat. Than you in advance for any advice. I have a Prestone thermostat installed.
As far as ACdelco thermostats, i dont know, i dont have one.
However, the pre 2200 as well as the 2200 engine is known to have odd remp fluctuations. Aything between 185 and 200 degrees is normal.
What fluid are you using? is it dexcool? and when you replaced the thermostat, did you remember to replace the gasket tooo?
http://members.rankmyride.com/djtorello
my mom's 99 cav, 2200 is the exact same way, @!#$ wont heat up inwnter, sugestion for now is use cardboard in front of your rad. im gonna check to see if there is a higher temp thermo stat for this engine too
Check the thermostate first it could be stuck open allowing the water to flow all the time and at highway speeds it would cool it down. Also I'd say check the level in the rad to be safe.
Good Luck
Semper Fi SAINT. May you rest in peace.
I have the same problem. My car started to overheat so i put an aftermarket t stat in it and ran cold. Got sick of that so went to the dealer to pick one up. But my engine kept overheating with the gm t stat in. Cartboard in front of the rad does work, make a couple hole the size of your fist and try that. If it runs to hot make more or bigger holes. I will try to fix this soon because it freeken freezen out. Just gotta wire up and install the furnace in the garage first.
Running hot in warm weather, no heat in cold weather, dude, that's a bad thermostat. I've had new ones that were worthless right out of the box. Go to a different parts store so you don't get another one from the same batch.
Adding cardboard in front is just a band aid, the problem is that your thermostat isn't closing and it's allowing coolant to circulate all the time. That's why it runs hot when it's warm out, too. If the thermostat doesn't close, the fluid in the radiator can't cool off, and the antifreeze just steadily gets hotter and hotter. And when you're on the freeway, the thermostat doesn't close to keep the engine at operating temp.
John Wilken
2002 Cavalier
2.2 Vin code 4
Auto
ide suggest a new stat also, try your local Advance auto or NAPA, stay away from the ZOne, they use cheap inferior parts. from my experience, autozone parts suck. also see abotu fluid levels too.
Fireboy153
Brady Fire Co. - Station 150
Long Live The Sunflower! (yea its not so "cool")
The temperature fluctuation did not start until I changed the thermostat, until then my temp guage always read around the halfway mark. One day after I replaced the waterpump the thermostat stuck so I purchased one from Murray's Auto Parts, a Prestone brand thermostat. That temp guage got to the into the yellow mark when sitting in traffic (back in the summer) then would cool back down to almost to the bottom of the tem guage once the car got going. I thought that I got a bad thermostat from Murray's so I went to Autozone and purchased one of their thermostats. This thermostat does the exact same thing. It is too cold outside so I take my car to the mechanic when it needs work. The mechanicd said my heat was fixed that some vaccum line was leaking causing the blend door not to go to the hot side which was causing my cold air on the highway. Took the car on the highway today and cold air once again and the temp guage dropped almost to the cold mark while driving. Stop and go driving the temp guage goes to the middle and heats up fine. So does everyone here think that a AC Delco thermostat will help?? I can't afford anymore of the mechanic's guesses as to what they think is wrong. Please help and thank you in advance for your advice. I think I will go with AC Delco thermostat....where do I get one??
you can buy a delco thermostat at any gm dealer, also some other stores may carry them aswell
well the delco stat is cheaper at a dealer than alot of aftermarket stats....however in my expirience this problem is a poor flowing radiator
