Faulty temp reading

[quote:d7b6b68e31="ronslay"]My 92 K2500 350 Silverado has an intermittent problem. It will go from normal to redline and remain there for a minute or so. The service engine light will come on. Then it returns to normal.

I have replace the instrument cluster twice, the sending unit and thermostat twice and it has a new OEM radiator.

The Chevy mechanics assure me that it isn't overheating.

I have no intention of getting rid of the truck, but this problem is baffling everyone. Any ideas?[/quote:d7b6b68e31]

Sir
We need the code/s in order to start diagnosis-Are you running the AC when the temp hits the redline?

[quote:9e6eea997d="rasmataz"][quote:9e6eea997d="ronslay"]My 92 K2500 350 Silverado has an intermittent problem. It will go from normal to redline and remain there for a minute or so. The service engine light will come on. Then it returns to normal.

I have replace the instrument cluster twice, the sending unit and thermostat twice and it has a new OEM radiator.

The Chevy mechanics assure me that it isn't overheating.

I have no intention of getting rid of the truck, but this problem is baffling everyone. Any ideas?[/quote:9e6eea997d]

Sir
We need the code/s in order to start diagnosis-Are you running the AC when the temp hits the redline?[/quote:9e6eea997d]

I inadvertently mislead you. I noticed today that it is the "check gages" light which comes on when the temp guage pegs.

Also, the truck is a 1993, not a 1992.

I talked with the mechanic again today and he said that he also replaced the wire between the sending unit and the guage.

Thanks for any light you can shed on this.

[quote:22cba6855b="ronslay"][quote:22cba6855b="rasmataz"][quote:22cba6855b="ronslay"]My 92 K2500 350 Silverado has an intermittent problem. It will go from normal to redline and remain there for a minute or so. The service engine light will come on. Then it returns to normal.

I have replace the instrument cluster twice, the sending unit and thermostat twice and it has a new OEM radiator.

The Chevy mechanics assure me that it isn't overheating.

I have no intention of getting rid of the truck, but this problem is baffling everyone. Any ideas?[/quote:22cba6855b]

Sir
We need the code/s in order to start diagnosis-Are you running the AC when the temp hits the redline?[/quote:22cba6855b]

I inadvertently mislead you. I noticed today that it is the "check gages" light which comes on when the temp guage pegs.

Also, the truck is a 1993, not a 1992.

I talked with the mechanic again today and he said that he also replaced the wire between the sending unit and the guage.

Thanks for any light you can shed on this.[/quote:22cba6855b]

And yes, the AC is running when I have the problem. I'm in FL, so I really haven't noticed whether it does it w/o AC.

I inadvertently mislead you. I noticed today that it is the "check gages" light which comes on when the temp guage pegs. Which ones?

If it has a clutch fan-might want the mechanic to check it-also have him check whether the computer is compensating for the extra load of the AC by increasing the idle.

Have him bleed the cooling system might be still air in it. When push comes to shove get him to perform a block and pressure