Question about 1991 GMC K1500

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Temp gauge always reading high

My temp gauge always reads very high close to 260 degrees before it cools down. i changed water pump thermostat coolant temp sensor and radiator. only pegs out when engine is very cool and does it once then the gauge does not seem to go as high had computer hooked to it while it ran and computer only shows 88 to 96 degrees celcius. any ideas what it could be.check engine lite works but does not come on only the check gauges lite comes on when this happens. truck heats good and never blows cool air like a head gasket indicator no antifreeze in oil or other way around. i'm thinking bad wire or bad gauge.

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Posted on Jan 02, 2017

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JMMARRERO59
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SOURCE: 1998 Dodge Durango no heat when using heater.

BLEND DOOR STUCK OR BROKEN. NEEDS TO REMOVE DASH AND HEATER/EVAP CORE BOS TO REPAIR REPLACE.

Posted on Jan 08, 2009

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SOURCE: Temp gauge went to 260 & stayed there. What could be the problem?

The only real way to answer your questions is for you to open the hood and look it over. Once it has cooled down, re-fill the cooling system (use water...it's cheaper and to do repair you will need to repalce it anyhow...Once full carefully look everything over to find where the leak is.Also make sure that the drivebelt is there. (from what you said, likely it is) If it's water pump, you will see coolant running out from under the pulley. Once you have looked everything over, if you have not found leak, start engine and close the cap...look again...as pressure builds, small leaks will become more obvious. If you don't find leak, remove the thermostat and change it.
After changing stat, if problem persists, it's likely that you have either a plugged radiator or an internal engine gasket problem. If you have any auxiliary electric cooling fans, make sure they are working and also check the fan clutch on the mechanical fan (it should not excessively freewheel when hot). Whole testing, any time you replace the radiator cap you must allow engine to cool down before removing it again. Watch temp gauge while testing...don't allow engine to overheat.

Posted on Apr 03, 2009

  • 14 Answers

SOURCE: my temp reads 195, after the car warms up and the

there is a sensor in the resivor bottle that malfunctions alot and all engines used in that vehichle make a ticking sound under load that is a rod knock nothing to worry about but to be safe check you fluid level.

Posted on Apr 07, 2009

  • 146 Answers

SOURCE: temp gauge often reads too hot, engine normal.

It sounds like your cooling fans are not comming on by themselves, but when you turn on the ac it forces them to turn on. Make sure relay is good, then replace coolant temp sensor, this may have failed no telling pcm to turn on cooling fans. Thanks

Posted on Jun 08, 2009

  • 1071 Answers

SOURCE: GMC Sonoma SLE 4.3L 1991- Coolant Temp Gauge Not reading

there are 2 coolant sensors one for gauge and one for ecm

Posted on Jul 23, 2009

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1 Answer

Changed out water pump and thermostat and vehicle runs high temperature what could be issue?


Reasons the Temperature Gauge Reads High

If the temperature gauge reads high, it could mean your engine is overheating. Another reason your reading might be high is you could be losing coolant. A small leak or evaporation may cause your radiator to slowly lose coolant. A third reason your temperature gauge reads high could be because the thermostat is broken. If this is the case, you may need a coolant temperature switch replacement. The last reason the temperature gauge could read high is because of a water pump, or water pump gasket failure. If the water pump is malfunctioning, it may need to be replaced by a professional.

What to Do If Your Temperature Gauge is High

If your temperature gauge is reading high, it means your car is overheating. This is a very serious matter and you should never drive an overheating car. If your car starts to overheat, shut off the air conditioner and open the windows immediately. If this does not reduce the overheating, turn on the heater as high as it can go. If this still doesn't work, pull over on the side of the road, turn off the engine, open the hood carefully, and wait until the vehicle cools down. Never open the radiator cap while the engine is hot - coolant can spray and burn you. Once the vehicle has cooled, take the car to a mechanic right away so they can diagnose the problem. Cars are especially susceptible to overheating in hot climates, like what's common in cities like Los Angeles, Phoenix, Las Vegas, or Atlanta.
The temperature gauge is an important tool in your vehicle that shows the temperature of your engine's coolant. Contact YourMechanic and have your car inspected for overheating if it reads too high, as this can cause serious problems...

Reasons the Temperature Gauge Reads Cold

On most vehicles, the temperature gauge reads cold until the engine has run for a few minutes. If the temperature gauge still reads cold after the engine has warmed up, the gauge may simply be broken. Another reason the temperature gauge could read cold is if the thermostat in the vehicle stays open. With the thermostat stuck open, the engine can be overcooled, causing a low temperature reading. If this is the case, the thermostat may need to be replaced.

Oct 28, 2017 | Cars & Trucks

1 Answer

2004 Impala ls temperature dash gauge


fans came late on those car,like 212 and second fan comes on at 224,you reprogram it to come a lot sooner,,other thing is there might be gunk inside the block,and coolant has hard time to pass through,and staying longer than enough in block temp goes high,even tough the radiator is doing it's job,it is just coming out block lot hotter than it suppose to be,and gauge read the block not the radiator

Apr 18, 2017 | 2004 Chevrolet Impala

1 Answer

1991 Chevrolet cavalier 2.2 auto Changed radiator, temperature switch, coolant sensor, thermostat, thermostat outlet housing adapter, gaskets. Gauge still shows running hot.. Max at 260-redline, But no...


The first hing I would do is confirm the engine temp with a scan tool. If the scan tool is reading a normal temp, 200 to 220 degrees with the fan coming on at around 220 degreese, and the gauge us reading much higher than the gauge is most likely bad. If the fans are not coming on than you need to look into that. Fuses, relays, wiring, fan motors would be the basic things to check. If you need more help with figuring out the fans let me know. If the fans are coming on, the temp gauge is reading the same as the scan tool data that there are a couple of possibilities. Either the system has air in it from nepot being properly bled or the headgket is bad forcing air into the system. Air will cause the cooling system to lock up. If you are try ing seeing the temp gauge spike to 260 degreese the head gasket is likely to have or will fail soon. Like I said if you have any further questions let me know and I'll be happy to help.

Sep 30, 2011 | 1991 Chevrolet Cavalier

1 Answer

Coolent leak temp gage 260


260 is too high, find that leak, if it is indeed leaking. Temperature should read 210 for normal operation. If your coolant level is normal, replace your thermostat as it is probably stuck closed. Could also, be a faulty water pump, so if it is leaking, this may be your problem too. Anyway, some things to check.

Jan 22, 2011 | 2004 GMC Envoy

1 Answer

Engine temp gage spikes to 260 degree when


are you sure the cooling fans are working?
Is the coolant temp gauge telling the truth?
have you lifted the hood and heard the coolant bubbling into the overflow?
Or heard the tinging sound of a red hot engine?
If he did a liquid test with the dye,and it changed colors it should have changed very fast,
Another thing to think about if he was to take the fan belt off,and pull the thermostat housing off,and removed the thermostat,Now pour coolant into the thermostat hole to almost the top,Now start the car and see which side the bubbles come from,left or right,that will be the gasket that is leaking not both.

Jan 23, 2010 | 1997 Chevrolet Monte Carlo

1 Answer

98 cherokee had gunky cooling system, got it flushed and temp gauge was reading low afterwards. diagnostic computer said the cooling system circuit had high input so i replaced one of the temp sensors. now...


STOP DRIVING.

Go to a shop and ask for a cooling system pressure test.

After they pump up the coolant system,they will point out is there any INTERNAL or EXTERNAL leak(s).


Internal leak is the first sign of blowing head gasket. (NOT GOOD)

External leak can just a small hose.


Start monitor cooling loss.

Start monitor the oil level

Change the thermostat and gasket.

The temp sensor is cheap. Change it at the same time.

Use 60/40 coolant mix is you has high odometer reading like 160,000+ miles


DO NOT ALLOW the coolant and oil cross mix.

As soon as it mix,you are ready for a majot head gasket repair.


Good luck.

Jul 15, 2009 | 1999 Jeep Grand Cherokee

1 Answer

Temp gauge often reads too hot, engine normal.


It sounds like your cooling fans are not comming on by themselves, but when you turn on the ac it forces them to turn on. Make sure relay is good, then replace coolant temp sensor, this may have failed no telling pcm to turn on cooling fans. Thanks

Jun 08, 2009 | 2002 GMC Safari

1 Answer

Temp gauge went to 260 & stayed there. What could be the problem?


The only real way to answer your questions is for you to open the hood and look it over. Once it has cooled down, re-fill the cooling system (use water...it's cheaper and to do repair you will need to repalce it anyhow...Once full carefully look everything over to find where the leak is.Also make sure that the drivebelt is there. (from what you said, likely it is) If it's water pump, you will see coolant running out from under the pulley. Once you have looked everything over, if you have not found leak, start engine and close the cap...look again...as pressure builds, small leaks will become more obvious. If you don't find leak, remove the thermostat and change it.
After changing stat, if problem persists, it's likely that you have either a plugged radiator or an internal engine gasket problem. If you have any auxiliary electric cooling fans, make sure they are working and also check the fan clutch on the mechanical fan (it should not excessively freewheel when hot). Whole testing, any time you replace the radiator cap you must allow engine to cool down before removing it again. Watch temp gauge while testing...don't allow engine to overheat.

Apr 03, 2009 | 1995 GMC Yukon

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