Temp stuck at 260 - any ideas?
Thread Starter
Race Director
Joined: May 2001
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Temp stuck at 260 - any ideas?
Car's running fine, plenty of coolant, never leaked, etc.
I haven't driven car in many months, went out for a spin and it's pegged at 260.
Got any ideas? Thermostat issue, and if so, got a specific part or part # that would be a good first look?
Many thanks.
I haven't driven car in many months, went out for a spin and it's pegged at 260.
Got any ideas? Thermostat issue, and if so, got a specific part or part # that would be a good first look?
Many thanks.
Thread Starter
Race Director
Joined: May 2001
Posts: 16,106
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Got to 260 in about 15 min. Will check on the hoses to see if coolant and fans running, thanks for the tip. If neither what would that be? Does the C5 Z06 Vette have a "limp" mode (reduced power) that it goes into? My '99 did once when the column lock thing engaged (boy was that not entertaining)...
Melting Slicks
Joined: Jul 2012
Posts: 2,507
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Even if there was a limp home mode, I wouldn't chance it. You can take the thermostat out, read what temp it's suppose to open on it, but it in a pot of water with a thermometer and see if it opens when it's suppose to. If it get that hot that fast should be easy to figure out, hopefully it's not a head or head gasket.
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 302
From: Columbia SC
Really better check out the thermostat. The fans shut off over 35 mph so if it is heating up over that speed the fans should not be the cause.
I would first check the radiator and make sure it did not pick up trash. Not uncommon.
Also could be the temp sensor is bad. Not hard to change.
Please, just DO NOT drive it at that temp in case it is real.
I would first check the radiator and make sure it did not pick up trash. Not uncommon.
Also could be the temp sensor is bad. Not hard to change.
Please, just DO NOT drive it at that temp in case it is real.
Thread Starter
Race Director
Joined: May 2001
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car's in driveway, no issues on driving it anymore. it's never done this before. also, i very quickly hosed off the motor (it was coated with dust) about 30 min before driving it. and i didn't cover the key electrical parts, which i normally do. my mistake. maybe i caused a short somewhere?
p.s. plenty of radiator fluid, it was not bubbling.
p.s. plenty of radiator fluid, it was not bubbling.
Burning Brakes
Joined: Feb 2012
Posts: 901
Likes: 2
From: Palm City Fl
How about trying a handheld temp sensor? Harbor Freight Tools has them fairly cheap, may not be the most accurate but should let you know if you have an actual temp problem.... I would try it out on something else first, that you know the temp of, just to make sure it is working...
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Le Mans Master
Joined: Mar 2004
Posts: 8,700
Likes: 298
From: Ft. Lauderdale Fl
Things to check...when temps spike:
Check radiator cap (needs to hold 16lbs.)
Check for collasped hoses.
Check for a stuck t-stat.
Make sure water pump is circulating coolant.
Check for debris between the radiator and A/C.(plastic bag/old T-shirt).
Check and make sure there is NO air in the coolant system.
Start with the above...good luck.
Check radiator cap (needs to hold 16lbs.)
Check for collasped hoses.
Check for a stuck t-stat.
Make sure water pump is circulating coolant.
Check for debris between the radiator and A/C.(plastic bag/old T-shirt).
Check and make sure there is NO air in the coolant system.
Start with the above...good luck.
Thread Starter
Race Director
Joined: May 2001
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fixed.
of all things i just turned on the fan and a/c.
it probably hasn't turned on since last summer.
pcm re-learning as well since battery was completely dead.
thanks a lot for all the ideas.
of all things i just turned on the fan and a/c.
it probably hasn't turned on since last summer.
pcm re-learning as well since battery was completely dead.
thanks a lot for all the ideas.
Melting Slicks
Joined: Jul 2012
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Race Director
Joined: Mar 2008
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From: Rio Rancho NM
you probably have gunk stuck in the condenser and radiator. You can't just hose it out you need a long air wand that will blow everything out. Way to many threads on this stuff already
Melting Slicks
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Race Director
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From: DFW TX
Thread Starter
Race Director
Joined: May 2001
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could very well have been.
car sat outside in sun for a few hours, took it out for half hour to drive and zero issues, temps, etc.
quirky, i guess. and 3boystoys, yep that's a big swing and i will pay close attention to it.
car sat outside in sun for a few hours, took it out for half hour to drive and zero issues, temps, etc.
quirky, i guess. and 3boystoys, yep that's a big swing and i will pay close attention to it.
Team Owner
Joined: May 2003
Posts: 23,480
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From: East Meadow NY
St. Jude Donor '12
If they are not coming on without the AC, then there is still a problem.
Thread Starter
Race Director
Joined: May 2001
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they're coming on their own now, no issues.
the car sat outside all winter for the most part and hasn't been driven in several months.
the car sat outside all winter for the most part and hasn't been driven in several months.
That is my concern. The OP could have shorted a sensor or has a bad relay. IIRC, turning on the AC forces the high speed fans to turn on. They should come on naturally once the car gets to a set temperature though.
If they are not coming on without the AC, then there is still a problem.
If they are not coming on without the AC, then there is still a problem.
Le Mans Master
Joined: Mar 2011
Posts: 6,835
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From: Columbia SC
Just for input:
Factory temp settings are low speed on at 226 degrees and off at 219 degrees. High speed on at 235 degrees and revert to low speed at 226 degrees. As stated both fans run at low speed and high speed and fans are commanded off by the PCM when the vehicle speed exceeds 35mph.
You can force low speed operation at 185 degrees by turning on the AC. High speed operation with AC on is still 235 degr
Factory temp settings are low speed on at 226 degrees and off at 219 degrees. High speed on at 235 degrees and revert to low speed at 226 degrees. As stated both fans run at low speed and high speed and fans are commanded off by the PCM when the vehicle speed exceeds 35mph.
You can force low speed operation at 185 degrees by turning on the AC. High speed operation with AC on is still 235 degr