Mechanical Water Temperature Gauge
 

Will a mechanical water temperature gauge go bad after the copper tubing has been in contact with the header. Temp gauge goes from 190 to 230+ during thermostate cycle, I've also replaced the thermostate thinking it was sticking, then noticed temperature copper lead was touching the header.

After moving it away from the header it still reads the same.

Re: Mechanical Water Temperature Gauge
 

No. it's the thermocouple that screws into the block that's temperature sensitive. The line is just a wire.

Re: Mechanical Water Temperature Gauge
 

I know the copper line is filled with ether to conduct the heat to the gauge. It's not an electric line.

Re: Mechanical Water Temperature Gauge
 

It might well have cooked the fluid inside the tube. I'd much rather have mechanical gauges then electric gauges though.

Re: Mechanical Water Temperature Gauge
 

That's what I had read before somewhere but was trying to confirm. Can the gauge or fluid be damaged if it contact with the header?

Re: Mechanical Water Temperature Gauge
 

I thought the fluid inside the line was coolant.

Re: Mechanical Water Temperature Gauge
 

I'm running into the same thing. But I think my problem is air pockets in the block, and no over flow tank. MY truck will idle just fine at 180 all day, but when I start to drive it the gauge will travel all over the place between 190-230.
I replaced the T-stat and thought I had fixed it, but it started doing it again on the next drive where I was driving the RPMS up for an extended period of time. I sure hope its not a head gasket. I'm going to spend all day tomorrow trying to burp it and figure this out.
Less than 100 miles on this motor.
(engine - 60 over flattop 327 with vortec heads, timing 12,32,47,)

Re: Mechanical Water Temperature Gauge
 

A neat trick to make sure there is no air in the block is to heat up the thermostat in a pot of water until it opens, then stick an aspirin in it to keep it open.
This will let the coolant flow to "burp" any air pockets, and the aspirin will dissolve after running for awhile, letting the thermostat work like normal.