Ok i am confused.... before i never had temps get above 205... my needle sat comfortably RIGHT on the center line...

after doing a mild rebuild on my engine and adding a few performance parts, now i find my temps ALWAYS above 200.. usually 210-220 or so. And i installed a 180 thermostat... so i am confused...

why are my temps UP after a colder stat?

has the air in youre coolant system been fully removed?.

really all depends, test your thermostat by boiling water and check the temp of the water and put your thermostat in it on a coat hanger until it opens as your watching the temp. maybe the thermostat is bad or a aftermarket part you put on isnt on correctly?

The lower temperature thermostat only means it's opening sooner. It doesn't necessarily mean the engine is going to run cooler. If you've got some different internals from stock, maybe bumped the compression, or different cams or injector timing then the engine is going to react different to heat. Higher compression=higher heat. Higher RPM=higher heat. Different ignition maps=higher heat (sometimes). The reverse is also true. Longer injector duration=lower heat. Longer cam durations=lower heat. ETC. I would think you should try a few things first.

1. As was said before, make sure the thermostat isn't defective. No matter what the vehicle, I've found STANT makes the best thermostats and caps. Don't bother with that expensive stuff or "race only" stuff. Many vehicles, many motors, always STANT. Autozone, Pep Boys, Strauss. Don't buy that NAPA crap. It's Chinese.

2. Check the radiator or pressure tank cap. Make sure it's in good shape. A new one isn't more than a few bucks.

3. Check the coolant. I know a lot of people that shortcut the coolant mixture. 50/50 coolant and water. It gives you the maximum boiling point and lowest freezing point. There aren't many over the counter coolants that are premixed so check the bottle. If you run straight antifreeze, you may actually be doing damage to the radiator and water pump due to the increased viscosity of the coolant. Coolant needs water to react properly.

4.. Make sure the fan is coming on. If the electric fan is coming on too late or not at all that could contribute to the increased temp. I had an '85 Camaro that ran really hot after a motor swap. I hot wired the electric fan to come on with ignition. After a few months on the motor, I invested in a heavy duty radiator which dropped the temps more than 30 degrees. If you have the cash, I suggest looking into a high rate radiator. Don't look at the core number. Look at the heat transfer rates. Modine makes a lot of heavy duty 3 and 4 core radiators which are great but you can't beat a Griffin 2 core aluminum because of the increased heat transfer.

My radiator cap was slighly loose, and my fluid was down a bit.... i topped it off and screwed it down....

I am running straight DEX-COOL as that is what the engine says... says not to dilute it and run only "dex-cool" so that is what i did....

havent had much time to test it since all this...

the fan seems to be fine.... and alot of the heat is during freeway speeds too... so fans wouldnt matter much.

Ummmm Dexcool has to be mixed with water. 50/50 mix is ideal. If you run straight Dexcool your asking for problems.

mitdr774 wrote:Ummmm Dexcool has to be mixed with water. 50/50 mix is ideal. If you run straight Dexcool your asking for problems.

exactly. ALL antifreeze must be diluted. whether you buy it diluted, or you dilute it yourself, you need it to be diluted. chances are, you just found your problem. honestly, i'm not a fan of dexcool and as soon as i got my car running, i switched to peak. no issues, no leaks, and the temp is perfect.



Edited 1 time(s). Last edited Wednesday, April 09, 2008 7:48 PM


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Agreed about the Dex-cool and it needing to be diluted. Another thing about your radiator/overflow cap, it's not the original is it?

I have been tracing a overheat problem since my new headgasket. Well, the other day I had the reservoir cap off and noticed the spring inside was rusted....replaced it an now everything is perfect.

Start with the basics though and work your way up as suggested by others.

Did you test the thermostat before you installed it? I always test them, pot and boiling water.


-Chris

Also you did not install a cooler stat. Stock is 180. Also as said if you had installed a cooler stat it would only open sooner.



FU Tuning

You have to pay attention when purchasing coolant.

Alot of places will sell Dexcool pre-diluted. Or you can purchase where it needs to be mixed 50/50.

If I actually purchase coolant- I will purchase the one that you have to dilute yourself. I found that they are usually around the same price- but when you dilute it, you get twice as much for the same price !!!

Its a no brainer.