I recently bought a 2002 Blazer that seems to have an issue with engine cooling. I had a 2000 Tahoe that ran at 190 consistently. But this Blazer runs up to 225-230 regularly in traffic, drops right down and sticks at 190 if I am moving. Is this normal or should I flush and fill the coolant and maybe replace the thermostat?

 

If the thermostat was sticking closed it would most likely only get hot on the initial warm up and wouldn't overheat after the stat opened. Its a definite possibility that it could be having poor circulation issues or if it has a clutch fan on it the clutch might be bad on it, had the same problem on my truck. Went to a flex fan and it works great even in traffic now.

 

sounds like a bad fan clutch, but can't hurt to change the thermostat too

 

Where exactally is the thermostat located? Is it under the black metal hose comeing from the middle top of the motor going to the upper radiator hose?

 

yup, thats where it is on a 2nd gen atleast, idk about the 1st gens.

 

Im looking to get my truck running a little bit cooler also. Ive done a 180 to my Jeep and it ran great, and same with my moms Suburban and everythings always ran a little bit cooler but when I did it to my Jeep my heat went after that, It sucked anyway but maybe a freak accident im not sure. The suburban never did that just ran cooler and better. Would a 180 thermostat be fine for my 99 4.3 and would it affect my heat at all?

 

use the search function and see what you come up with i know this has been discussed a number of times.

 

Oh alright sorry

 

Quick, simple answer - no. You run the risk of the engine staying in open loop operation and your gas mileage and performance will take a nose dive. Stay with the 195 degree thermostat.
If you have further questions, please start a new thread so we don't hijack this one.

 

Sounds like a defective fan clutch. Also, check to make sure that your fan shroud is in place.