Topic: Cooling Problem Puzzle
in Forum: C3 Cooling and Heating Systems
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The radiator is full,the overflow tank is full(at cold line).When I go out the temp gauge red lines for about 10-20 seconds then goes to normal operating temp.The thermostat was changed last year.I'm thinking of changing the top and bottom hoses (seems to me I read that her something about them breaking down)as soon as I can get the car up to the base to put it on a lift.Any other ideas for me to check .Oh once I 'm driving on open road there is no problem.Can the wire for the temp gauge being close to headers effect the temp?
|UPDATED|6/13/2012 6:22:01 AM (AZT)|/UPDATED|
Thanks
Rick
|UPDATED|6/13/2012 6:22:01 AM (AZT)|/UPDATED|
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Frederick, MD - USA
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Does this occur right after startup or is the engine at normal operating temperature when this happens? If right after startup the engine hasn't warmed up to normal temps so it can't actually be running hot. In that case I would look toward the sending unit or even the gauge.
You said at highway speeds it runs normal so it can't be the lower hose collapsing under vacuum...the upper hose is likely not involved in the problem.
There's a possibility there could be an air bubble in the system that needs bleeding out. You could also have a sticking thermostat, regardless of how old it is.
From your description I would think the problem is sending unit/gauge related. If the sending unit wire is that close to the exhaust manifolds/headers, it could be burned through and maybe grounding out at times.
There are ways of testing the gauge...do a web search and find the procedure if someone here doesn't already know it.
Have had the same thing happening with my pick up truck for years. I'd put my money on a delay in the initial opening of the t-stat. I have a 195 degree t-stat and the temp runs up over 200 on the initial warmup then t-stat opens and it run normal temps at all operating ranges. I have had no detrimental effects from this happening. It may be a normal operating deal for your t-stat.
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DanT
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I'm leaning toward the t-stat, too, but need a little more info first.
How long after start-up is it before the gauge runs up that high?
How long does it take for the gauge to come back down to "normal" after going "hot"?
How long after start-up is it before the gauge runs up that high?
How long does it take for the gauge to come back down to "normal" after going "hot"?
Joel Adams
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Purchase an in expensive Laser gun ...point it at the thermosate housing & get a true reading. You might not have any problem except a bad sending unit, wire or gauge. make sure your sending unit is getting a good ground...metal to metal going into the intake manifold. On my 73 the gauge reads almost 200 degrees but the true reading is 175.
Alan
Well today while I was out I picked up a new sending unit(who knows when it was last replaced or even at all) and a new thermostat .I'm taking the car up to the base and put it on a lift (I got a couple of little things to do) and go to it.I'm going to a industrial parts supplier and see if they carry heat sleeves (we use them at work and if they can protect wires from the heat of liquid metal then headers shouldn't be no trouble.
Rick
Hope that does the trick, Rick!
|UPDATED|6/13/2012 4:20:42 PM (AZT)|/UPDATED|
Barry
|UPDATED|6/13/2012 4:20:42 PM (AZT)|/UPDATED|
in Forum: C3 Cooling and Heating Systems
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