Engine Operating Temperature? What is safe?
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Joined: Jul 2008
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Engine Operating Temperature? What is safe?
Hey everyone,
I have a 1989 Corvette Convertible. While driving (Midwest) during warm days, my temperature gage readout gets up to 225 easily. I have been told by other car junkies that that temperature is way too high and that if it ever gets that high I should immediately pull off the road and turn the engine off. My question is what is the drop dead temperature that I need to concern myself with? Like i said the temperature gage easily goes up in stop and go traffic to 225-230 in a no time and I just want to know where the "red line" or "warning" line would be on a non-digital dash.
Coolant was replaced last summer and this did not change any of the operating temperatures.
Thanks in advance.
I have a 1989 Corvette Convertible. While driving (Midwest) during warm days, my temperature gage readout gets up to 225 easily. I have been told by other car junkies that that temperature is way too high and that if it ever gets that high I should immediately pull off the road and turn the engine off. My question is what is the drop dead temperature that I need to concern myself with? Like i said the temperature gage easily goes up in stop and go traffic to 225-230 in a no time and I just want to know where the "red line" or "warning" line would be on a non-digital dash.
Coolant was replaced last summer and this did not change any of the operating temperatures.
Thanks in advance.
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Your temps are normal. GM designed them to run this temp for meeting emissions standards.
Team Owner
Joined: Mar 2001
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From: Cincinnati, Oh USA
225 will harm nothing in your engine. Your main fan comes on at 228 F and the auxilliary fan comes on at 238 F. GM says to shut the engine off at 260 F and let it cool down. I am sure they say this because 50% antifreeze at 15 psi boils at 265 F and boiling coolant doesn't transfer much heat and your heads will get too high temp. Actually, if you have the 195 thermostat in your engine, 225 while underway is too high a temp (but not harmful). C4's pull air in from the bottom and all kinds of road debris plugs the bottom portion of the radiator. You should get the bottom fins cleaned out and you should experience coolant temp very close to your opening temperature of your stock thermostat when you are under way (over 30 mph). Don't bother installing a lower opening temp thermostat, it won't do anything to your operating temperature, use the stock thermostat.
People that told you 225 is too hot don't know anything about automobile cooling systems.
People that told you 225 is too hot don't know anything about automobile cooling systems.
Advanced
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I've been in my vette ALL freggin day long today, and my engine didn't go over 216 degrees once. And it's hot as ***** here in FL right now. I don't like running hot, but like people were saying.. it's designed like that.. so I guess I'm running with it.
Safety Car
Joined: Jan 2004
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Since alot of these threads have been getting posted lately. How long does it take for say the Plenum to cool off after shut down? I noticed I had shut the car off in the evening and came back out around 4-5 hours later to check on something. And noticed the Plenum was still hot to where you couldn't leave your hand on it. I figured after 4-5 hours it would have cooled off by then.
Slingshot
Joined: Dec 2001
Posts: 3,817
Likes: 24
From: Charlotte NC
225 will harm nothing in your engine. Your main fan comes on at 228 F and the auxilliary fan comes on at 238 F. GM says to shut the engine off at 260 F and let it cool down. I am sure they say this because 50% antifreeze at 15 psi boils at 265 F and boiling coolant doesn't transfer much heat and your heads will get too high temp. Actually, if you have the 195 thermostat in your engine, 225 while underway is too high a temp (but not harmful). C4's pull air in from the bottom and all kinds of road debris plugs the bottom portion of the radiator. You should get the bottom fins cleaned out and you should experience coolant temp very close to your opening temperature of your stock thermostat when you are under way (over 30 mph). Don't bother installing a lower opening temp thermostat, it won't do anything to your operating temperature, use the stock thermostat.
People that told you 225 is too hot don't know anything about automobile cooling systems.
People that told you 225 is too hot don't know anything about automobile cooling systems.
Normal operating temp for an L98 engine is targeted at 195 degrees. Base fan goes on at approximately 225 degrees and off at 212 degrees. Auxiliary fan (if you have heavy duty cooling) goes on at approximately 236 degrees. On the open road or the highway, your engine should run around 195 degrees. If you are running warm most of the time, you might have a faulty thermostat or, as previously mentioned, radiator blockage. Attached is a good write-up on how to clean the debris from between your radiator and the A/C condenser. Cleaning this debris out and changing your thermostat should solve your problem.
Let us know how you make out.
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Drifting
Joined: Sep 2002
Posts: 1,642
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From: Suwanee,Ga
Hey everyone,
I have a 1989 Corvette Convertible. While driving (Midwest) during warm days, my temperature gage readout gets up to 225 easily. I have been told by other car junkies that that temperature is way too high and that if it ever gets that high I should immediately pull off the road and turn the engine off. My question is what is the drop dead temperature that I need to concern myself with? Like i said the temperature gage easily goes up in stop and go traffic to 225-230 in a no time and I just want to know where the "red line" or "warning" line would be on a non-digital dash.
Coolant was replaced last summer and this did not change any of the operating temperatures.
Thanks in advance.
I have a 1989 Corvette Convertible. While driving (Midwest) during warm days, my temperature gage readout gets up to 225 easily. I have been told by other car junkies that that temperature is way too high and that if it ever gets that high I should immediately pull off the road and turn the engine off. My question is what is the drop dead temperature that I need to concern myself with? Like i said the temperature gage easily goes up in stop and go traffic to 225-230 in a no time and I just want to know where the "red line" or "warning" line would be on a non-digital dash.
Coolant was replaced last summer and this did not change any of the operating temperatures.
Thanks in advance.
All the above is accurate.
My 89 runs hot as that [ automatic]. But even after driving around Road Atlanta in 95 degree heat this weekend we never saw anything over 250 degrees [ which is hot, granted].
The ratio of coolant:water will affect the temperature.
This will sound contrary, but reduce the amount of Anti freeze to say 25% antifreeze use DISTILLED water! and but some "Water Wetter" .
Water will transfer the heat better than Anti Freeze. Just remember to get it back up in the winter months.
TJM
Drifting
Joined: Sep 2002
Posts: 1,642
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From: Suwanee,Ga
Since alot of these threads have been getting posted lately. How long does it take for say the Plenum to cool off after shut down? I noticed I had shut the car off in the evening and came back out around 4-5 hours later to check on something. And noticed the Plenum was still hot to where you couldn't leave your hand on it. I figured after 4-5 hours it would have cooled off by then.
That's weird? I was laying my hand on the plenum 15 minutes after taking laps, this weeked?
We discontented the Throttle body heater on the '89. Easy to do, and might have a lot to do with heating the Plenum, but 5 Hours?
Unless your parked in Hell that seems a long time?
TJM
☠☣☢ Semper Ebrius ☢☣☠
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From: Virginia
Cruise-In IV-V-VI-VII Veteran
St. Jude's Donor '06
My bike gets up into the 300s.On any modern (as in, since the 1970s) water-cooled engine, 220 or so isn't going to damage anything.
Safety Car
Joined: Jan 2004
Posts: 3,759
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That's weird? I was laying my hand on the plenum 15 minutes after taking laps, this weeked?
We discontented the Throttle body heater on the '89. Easy to do, and might have a lot to do with heating the Plenum, but 5 Hours?
Unless your parked in Hell that seems a long time?
TJM
We discontented the Throttle body heater on the '89. Easy to do, and might have a lot to do with heating the Plenum, but 5 Hours?
Unless your parked in Hell that seems a long time?
TJM
I know the plenum will be too hot to touch just with the car sitting outside in 80+ degree weather with the sun out.
Thread Starter
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Joined: Jul 2008
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I was figuring that it could have not been that bad. Thanks for all of the information. I only have 59,000 on it so i am not sure i really want to disassembly the radiator quite yet. I am not even sure I could handle it..........
Once again thanks to corvetteforum.com and everyone!!!!
Once again thanks to corvetteforum.com and everyone!!!!
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Joined: Apr 2014
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From: hacienda heights ca
