When I'm driving In my car it rides at about 170/180, but when I am idling it rises fast, almost to 260, to the 3/4 mark.

What's the deal?? Do I need a new thermostat? Should I get a 160 degree stat? I'm afraid it's going to everheat. Any ideas?


Thanks

MaVeN

 

Are your radiator fans kicking on?

 

do you have thermostat in your car?

 

Sorry dint read the update, replace thermostat before anything elses. Then check compression of the radiator.

 

flush out with water a couple times too, get the junk out.

 

Mine was doing the samething. Fans weren't coming on. I ended up running a manual fan switch so I could cut the fans on when the temp started to rise.

 

First off you should have a 195º Thermostat in the engine. IT should run around 210 ish all day long, maybe a little higher with the A/C on and or in traffic.

IF you are getting really high temp then a fast drop you prolly have air in the system that is causing a vapor lock type of situation. What happens is the steam pressure holds the water in the bock and does not allow it to flow into the radiator, and thus overheats. Follow the purge proceedures for your engine.

If it is the 3.8L you are to run the engine to operating temp, keep the radiator full as the engine heats up. Once the engine is full hot open the purge valve on the upper hose fitting. This will cause the air in the bock to escape and the fluid in the radiator to drop. GM says rinse and repeat this step 5 times. I do it as many as it takes to get everything stable. Make sure you refill the radiator between purges.

Massey

 

sht i just keep the cap off run the car and it will burp when it heats up put more fluid in and your all set thats how ive always done it on all my cars (im 22 and have owned like 50 cars 45 of which were lot cars tho not street legal)

 

I think the 3.4L can be purged like that but dont quote me I have not yet owned the 3.4L The 3.8 has the water outlet higher than the radiator so you have to use the purge valve or you will get air trapped up there. I know this from experience!

Trapped air is the only thing I can think of that would cause your issue.

Massey

 

didnt know that and ive owned a couple 3.8 but the only time ive had to put fluid in one of those is when i hit a tree and put a branch thru the rad (lot car)