Mechanical Water Temperature Gauge - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jsburton69 · 12-11-2009, 04:30 PM

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.

unclewatts · 12-12-2009, 12:39 AM

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

jsburton69 · 12-12-2009, 12:54 AM

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

mr48chev · 12-12-2009, 01:27 AM

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

jsburton69 · 12-12-2009, 10:47 AM

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?

airdale94 · 12-12-2009, 02:50 PM

I thought the fluid inside the line was coolant.

AustinScott · 12-12-2009, 08:28 PM

Quote:

Originally Posted by jsburton69

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.

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,)

toddtheodd · 12-12-2009, 08:43 PM

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.

12-11-2009, 04:30 PM	#1
jsburton69 Registered User Join Date: Jun 2007 Location: Little Elm, Tx Posts: 14	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.

12-12-2009, 12:39 AM	#2
unclewatts 70 Chevrolet=Obsession Join Date: Jun 2009 Location: nice ca Posts: 1,067	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. __________________ I'm Just like my truck. Old, Ugly and Grouchy. Except my truck starts easily in the morning and doesn't smoke! IT'S NOT EASY BEING GREEN! -Kermit the frog 1970 Chevrolet C-10 Longbed Stepside : 350, Muncie M20, 3.08 GM corp. positraction Forest green exterior/light green interior(Where all my money goes) 1996 Toyota Corolla (Parts runner)

12-12-2009, 12:54 AM	#3
jsburton69 Registered User Join Date: Jun 2007 Location: Little Elm, Tx Posts: 14	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.

12-12-2009, 01:27 AM	#4
mr48chev Registered User Join Date: Jul 2007 Location: Toppenish, WA Posts: 15,446	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.

12-12-2009, 10:47 AM	#5
jsburton69 Registered User Join Date: Jun 2007 Location: Little Elm, Tx Posts: 14	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? Last edited by jsburton69; 12-12-2009 at 10:47 AM.

12-12-2009, 02:50 PM	#6
airdale94 Registered User Join Date: Jan 2007 Location: Topeka,KS Posts: 778	Re: Mechanical Water Temperature Gauge I thought the fluid inside the line was coolant.

12-12-2009, 08:43 PM	#8
toddtheodd The oddest Todd around Join Date: May 2004 Location: Miami, Florida Posts: 1,418	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. __________________ "The greatest pleasure is to vanquish your enemies and chase them before you, to rob them of their wealth and see those dear to them bathed in tears, to ride their horses and clasp to your bosom their wives and daughters." Ghengis Khan IIOY??? Last edited by toddtheodd; 12-12-2009 at 08:43 PM.



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