1992 Chevy Blazer S-10 temp. gauge

Maybe a problem with the temp sending unit? Air in the system--radiator cap. Does the fan work ok? Combustion gases getting into the cooling system. Coolant reservoir, where applicable, does it fill up, when that hot?

We changed the sending unit and radiator cap. The fan works fine. Coolant reservoir is at full and does not fill up when the gauge says it's 260.

You can use an external type reading for engine temp, see if reading is close to the same as temp gage, if not, maybe an issue with gage or wiring circuit. I don't have any other ideas at the moment.

Thanks for your time. No one else had any other ideas either.

It's hard to help people over the internet unless they can do some testing. All I can do is make suggestions on what to test, the rest is up to you.

Have a shop check the radiator to see if it's plugged - or slightly plugged up ! A friend of mine had the same problem with his '89 4.3 motor S10 Blazer. Also check to see if you can see thru both the a/c condenser/radiator for light, being as air might not be able to pass thru them & do the cooling that the motor needs.

Ford Man in Michigan

I'd still have to verify the temp gage. Flushing the system is a good idea.

Questions for you, to help us help you! Can you locate another temp gage to check the operating temp of the motor? Is the coolant temp sensor working correctly? Has this motor overheated "before" this problem started? This last question is the most important because "if" the motor froze up (mid january) because coolant wasn't strong enough to protect it......"that" is where the problem is !

Ford Man in Michigan
p.s.
if the motor overheated before....you may have blown head gaskets !

Yeah it is possible.

Thanks everyone... we had the radiator checked and it had good flow. My friend decided to by another radiator and in the mean time we decided while we had it tore apart we were just going to change the sending unit and the sensor... we had flushed the radiator and checked the coolant. The only thing we really found was some hair line cracks in the neck of the radiator. But we had already changed the other stuff and couldn't us the external temp gage til we got the radiator back in. But it is heating very well and we have no more problems with the gage reading hot. But it has never over heated. Thanks again.

Maybe you got it going your way?