Nick90vetteguy
Well-known member
SO my vette is overheating agian, could it be because my ceramic headders give off more heat than stock? did a coolant flush, fans turn on, could it be my gauge be wrong?
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How Hot is Hot?~??:confusedSO my vette is overheating agian, could it be because my ceramic headders give off more heat than stock? did a coolant flush, fans turn on, could it be my gauge be wrong?
1) 250-260 is in the danger zone. If you are seeing those ECTs regularly and have been seeing them for a while, engine damage is possible. I'd stop driving the car and start some cooling system diagnosis.
2) The problem is not your ceramic-coated headers. They will reduce heat radiated from the exhaust but will not affect ECT enough to put it to 250-260.
3) For the engine to run that hot because of lean AFR, it would have to be really, really lean and that would turn on the check engine light and set a code for lean exhaust.
Has the light been on? If so, what code(s) were set?
4) Whether the coolant is "traditional" antifreeze or Dexcool is not an issue, here. Also, Dexcool was not used in a 90.
With respect to the very high ECT, first I'd remove the top of the cooling stack and inspect the area ahead of the radiator and the space between the hvac condenser and the radiator for debris. If you see any, remove it.
Next, I'd verify the cooling fan(s) work using the information in the Factory Service Manual.
After that, I've make sure your aftermarket thermostat is not faulty
Check to make sure the radiator is not restricted.
Let us know what you find.
Dexacool thats what i meant thanks haha, ok well no codes have came up, SES light hasnt been on at all this year, nothing comes up when I poke it with the paperclip, where should I look to find any debris between the fans and radiator?
Yes. L98 really likes to trap air after any type of coolant maintenance that requires you to drop coolant levels. Procedure provided is very similar to the FSM. I improved my success rate to 100% by reving the engine and holding it just enough that lowers coolant levels an inch or so, then topping it off quickly and install the cap. Until the next coolant maintenance, I never need to remove the radiator cap. I monitor levels in the overflow tank.