I have a 2000 Monte Carlo that I recently purchased, The car seems to take forever to warm up when parked and idling , and when i drive it drops to about 140- 150 degrees I do have heat but doesnt seem like its as hot as it should be. I opened the radiator and let it run ( took almost 20 min to get to 195)and it didnt seem to be flowing constantly so i dont think the thermo is stuck open ( though it was sripping out the fill spout a little), I checked the antifreeze and it only tests to +5 degrees, could this be why the car wont warm up properly? or should i just change the thermostat anyways, I have it already but it looks like a pita. thanks

 

Sounds like the thermostat is stuck open like you stated. Time for a new thermostat and new coolant, get rid of that GM crap and your gaskets will thank you!

 

bought from a friend who had his intake gaskets done and i convinced him to get rid of the dex cool ....I have had a few supercharged bonnevilles and have seen the effects of the evil dex-cool on many many intake gaskets. If the thermo was stuck open wouldnt I have seen more constant coolant flow?

 

Its open so it wouldn't stop flowing which is why its not able to heat up to where you want it to

 

I missread your post, the coolant system being pressurized, did you maybe stop the flow when you opened the radiator?

 

i opened the radiator then started car, I will probably just switch it and the fluid out to be safe, any tips on the thermo replacement, i am going to try to get to it without removing tb or crossover

 

Change the T-stat. You're existing one is stuck open OR is not properly rated for your car (such as it may be T-stat that opens at a lower temp).

As for Dex-Cool, current Dex-Cool has nothing to do with nylon intake gaskets going bad, the fact nylon is a crap material is why they go bad. I've changed nylon gaskets twice on my '94 Grand Am, it's ran nothing but the good ol' green stuff and they still went bad.

 

It was a stuck open thermostat...had to go get some obstruction wrenches from harbor freight.....throttle body was a pain in the ....has to be the most time consuming thermostat I have ever done....thanks for the help.

 

I have not done a T-stat yet on a 3400, but since it's based on a 3100, I know what I'm in for. I can do a T-stat on a 3100 in roughly an hour. Annoying how on many other engine designs, it's like a 5 minute task.