Help! oil & coolant temp

[hotshotzny]

what is the acceptable oild and coolant temp at normal operating.... tonight while watching some racoons with my co-pilot for about 15 - 20 minutes the coolant temp shot up to about 250+ and the light came on.... within seconds of moving again the temp went back down to where the light went off and never heated back up.... my only worry is it was pretty cool out and in the land of highway construction that is never finished sitting for 10 - 15 minutes on a hot summer day isnt out of the ordinary...

 

[tonybabb]

what is the acceptable oild and coolant temp at normal operating.... tonight while watching some racoons with my co-pilot for about 15 - 20 minutes the coolant temp shot up to about 250+ and the light came on.... within seconds of moving again the temp went back down to where the light went off and never heated back up.... my only worry is it was pretty cool out and in the land of highway construction that is never finished sitting for 10 - 15 minutes on a hot summer day isnt out of the ordinary...

On my 89 coupe the temperature rises in a few minutes of sitting but when it gets to 225 the electric cooling fan kicks in and reduces the temperature down to around 215 witin a couple of minutes. You can hear when the fan kicks in, did yours start?

 

[hotshotzny]

On my 89 coupe the temperature rises in a few minutes of sitting but when it gets to 225 the electric cooling fan kicks in and reduces the temperature down to around 215 witin a couple of minutes. You can hear when the fan kicks in, did yours start?

honestly i wasnt paying attention at the time and it caught me off gaurd.. but i do know the fan does work or atleast has in the past

 

[ken mohr]

That is not normal.

Next you are dirving it when you get home let it set and idle. Watch for the fan. If it doesn't turn on by 235* drive it enough to cool it and start checking fans.

 

[G Winter]

I installed a switch to the relay grounds so I can turn on both fans anytime I feel extra cooling would be a good idea.
This gives me a little jump on the temp in traffic. You could have bad temp switch in the head or bad relay.

Glenn

 

[Tuna]

I have seen coolant temps reach 235-239 in stop and go traffic in the Houston area on late C4's with LT1 or LT4 engines but never higher and LT1/4 engines generally have higher coolant temps than L98 cars. So, 250+ with warning lights sound like problems exist and need to be checked out.

Btw, at the times I saw these high temps on the LT1/4 cars, the A/C was off and the windows were down. Turning on the A/C allowed the second fan to stay on and cool the cars down more.

 

[redvett]

Have you recently cleaned the radiator? Trash collects between the rad. & A/C condenser and will seriously block air from passing through the radiator.

 

[hotshotzny]

ends up its a bad sensor... pulled it off and grounded it out and the fan works..ordered a new one today

 

[ken mohr]

Glad it wasn’t anything serious

 

[hotshotzny]

Glad it wasn’t anything serious

yea me too.. thanks.. good thng is its pretty cool out so i can drive it if i need to

 

[Jeff]

Glad it wasn’t anything serious

...or CAUSED anything serious.

My '91 L98 fan kicks on at 226 (operating temperature) and off at 206. Of course, the coolant temperature doesn't drop the very second the fan kicks on (actually, continues to rise a few more degrees), so around 235 +/- is normal. Although this high operating temperature is normal by design, it's certainly annoying and seeing the gauge touch that little shaded area is at the very least, discomforting. hnoes

Anyway, 250 and a warning light is a sign that something is definately wrong. Glad you got it fixed.

 

[CorvetteArchives]

ends up its a bad sensor... pulled it off and grounded it out and the fan works..ordered a new one today

Whew! Dodged a bullet on that one!
Last time mine went up that high the thermostat had stuck. I replaced with low temp 160 degree one and replaced the fan switch with a 185 and NEVER had problems for 10+ years.
BTW, also did the cooling fan relay upgrade as added insurance...sold by other vendors too
Corvette Cooling Fan Control Relay & Wiring Harness Repair Kit, Upgrade, 1984-1994