When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have a 2003 base corvette.
mall lf a sudden it started running around 240.
So I took and replaced the thermostat with a 160 rather than the stock 195. I also blew out the Raditor and condenser coil and change the antifreeze.
my issue is. While sitting still I range between 195-205. When it hits 205 fan comes on and brings it back to 195. But while driving not hard just anytime giving it gas or going up a hill the temp will go up to 250. I have never seen a car that got hotter while driving any ideals
I have a 2003 base corvette.
mall lf a sudden it started running around 240.
So I took and replaced the thermostat with a 160 rather than the stock 195. I also blew out the Raditor and condenser coil and change the antifreeze.
my issue is. While sitting still I range between 195-205. When it hits 205 fan comes on and brings it back to 195. But while driving not hard just anytime giving it gas or going up a hill the temp will go up to 250. I have never seen a car that got hotter while driving any ideals
How hot is it out where you live? What are the atmospheric conditions? These cars do run well in the 200s especially if not driving at speed. 250 seems excessive though. .
Browse the forum on how to remove the air from the cooling system. It takes a few tries to get it right. Might solve your problem. Also, are the front air dams still in place?
2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
could also be the surge tank cap... the 160 thermostat isn't going to make any difference unless you have the fan settings adjusted, personally I'm not a fan of them
Last edited by StingrayRebel; May 23, 2021 at 04:42 PM.
You might want to have the antifreeze tested for combustion gases which could indicate a head gasket failure. Also, I would stick with the OEM thermostat. Despite what some folks think, you CAN have too low of coolant temp with the wrong thermostat.
250 while driving above 35 mph is too hot. As others have suggested it is possible that there is still air trapped in the heads. That could have happened when you changed thermostats. There is a specific procedure in the Factory Service Manual for purging air from the heads after changing coolant or dismantling the cooling system in any way because opening the cooling system is likely to cause air to get trapped in the heads. Try this first.
High temperatures at highway speeds can be caused as already mentioned by air trapped in the heads, other causes could be radiator fins clogged with road debris. Fans are not a cause of highway speed high temperatures, as they are switched off once the car exceeds 35 mph.
It is 84 degrees where I live. While idle it runs 194-200. Bit while driving any time above 2000 rpm it will go up to 250 degrees
This happened to me, even with a large DeWitts radiator!! Temps weren't going to 250°, but they were all over the place, 172°-210°+, on the freeway, level ground. 60° ambient temps. 220°+ going uphill. I thought I had a head gasket going out. It wasn't. I was low on coolant!! I was low on coolant because one of the factory spring hose clamps, well, lost its spring, tension, that is! Leaked just enough that nothing was under the car. It would evaporate quickly. I bought a conventional stainless steel band/hose clamp, filled it with coolant, no trouble since. Bad situation, because you're not only losing coolant, but as the internal pressure builds, it can't build enough pressure to raise the coolants boiling point before bleeding off past the bad clamp. A double whammy, so to speak. So check all your clamps, and coolant level!! I was in the process of starting to remove my heads when I grabbed the hose on the water pump that goes to the heater, and before I could get my pliers on it, coolant came out all over around it!!!
Glad you got it fixed. I'd recommend swapping back to a stock temp tstat now. I ran one for ~2 years in, all it's going to do is take your car longer to reach operating temp.
Over heating issues
