Temperature guage not accurate

[Silverandblack]

My 1977 vette runs well apart from this issue, the temperature guage when starting the engine from cold shows 220 degrees. Then goes up nearly in to the red after a few minutes, the temp guage and temp sender unit has been replaced along with a new covered wire to connect to the temp sender on the wiring loom.

The engine temperature when measured with a digital unit shows my engine, running at a modest 180 degrees. Therefore the problem I have been told, is that of a resistance problem in the wiring system. And I'm told not to worry about it.


However I find it difficult when stuck in traffic to watch the guage creep deep in to the red . Expecting the engine to crack at an moment, i have also put in a new fan and clutch and the cooling system has no leaks. I had the radiator recored too , but this temperature issue worries me due to the huge sum of money invested in my baby.

Peter

 

[Hib Halverson]

Considering you have a 42-year old system, I'd do the following. First, check for high resistance in the sender to gauge wiring and/or connections.

If the wiring is ok, replace the sender.

If the wiring has no high-resistance and the sender is new and you still have a problem. I'd replace the gauge.

 

[Art Jett]

If it weren't such a huge PITA to get the gauges out, I would replace mine. I have almost the same issue. I have been through 3 senders from different vendors, the wire is intact and my gauge reads a consistent 20*-25* high. I can read my billet water neck @ 179* and the gauge will be reading 200*-210*. If nothing else, when I have to get in there for some reason, I think I'll pull the needle off the pin and replace it so it will be reading closer to the actual temp. I just don't want to get that far into the dash (AGAIN) for just that.

 

[Vette79]

If it weren't such a huge PITA to get the gauges out, I would replace mine. I have almost the same issue. I have been through 3 senders from different vendors, the wire is intact and my gauge reads a consistent 20*-25* high. I can read my billet water neck @ 179* and the gauge will be reading 200*-210*. If nothing else, when I have to get in there for some reason, I think I'll pull the needle off the pin and replace it so it will be reading closer to the actual temp. I just don't want to get that far into the dash (AGAIN) for just that.

I went through several as well doing my build but actually found one that was really close. Guess I got lucky...