I have a good aluminum radiator, 160 degree tmermostat, good water pump, aluminum radiator hoses, dual fans, shroud, etc. A great cooling system.

Since I installed my headers, my temp gauge keeps rising and rising (slowly). So I got concerned when my temp got to 200 I turned off my engine and took out my digital temperature gauge. I checked the radiator inlet tube temp (it's aluminum, not rubber), and it was at 140. So I let off the pressure in my radiator and tested the temp of the radiator fluid, and it was 155, not 200.

My car's temp gauge is plugged into the driver's side cylinder head, in between the #1 and #3 primary header tubes. Could heat be radiating from the headers into the temp guage, giving me an improper reading?

My temp sensor is located just like yours between tubes 1 & 3. I don't have this problem. Maybe your sensor is not right for your application? YOu could pull it out and put it into a pan of hot water (with a known reference temperature) to calibrate?


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Regards,
RLK
TC Member #918
ACES member
Metroplex Muscle
My Cars (http://home.texoma.net/~rknipe/)

The answer is YES>...there is considerable difference between head sensing and intake at the thermostat sensing. These temps run hotter, esp when slow moving air recirculates and metal exhausts radiate heat towards these sensors, and 200 degrees is no big deal really. I would start getting nervous at 240ish...and still going.

As long as the temperature stabilizes then no problem. It's run away heat that is the issue and loss of coolant. It sounds like you designed a good sound system, but needs some tuning....if your system is not stable.

IR guns on the surface of a cooling conduit is not an accurate way of sensing actual metal temps. Even the top of the radiator will be cooler than the actual head or engine coolant. YOu can calibrate your sensor in boiling water and a power supply as the previous poster suggests.

Cooling tips at my cooling forum at www.inccn.net/techforum.htm (http://www.inccn.net/techforum.htm) enjoy!

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Steve Jack - ConceptOne Pulleys and Brackets / Engineering & Marketing Technologies

[This message has been edited by HOTRODSRJ (edited 02-10-2002).]

I know that 200 is nothing to worry about, and I've seen it get to 220 and it wasn't stopping. I haven't tested to see HOW hot it gets. Maybe I'll test that out tomorrow after work.

So...because the heat from the headers are affecting the reading, that makes the reading unreliable?

Where else can I put the sensor?

EDIT: OH!, let me clarify...
The gauge I use in my car is a mechanical gauge, and the digital gauge is a digital multimeter with a temp gauge built in. They are two totally different gauges. And I've found the multimeter temp gauge to be dead on accurate.

[This message has been edited by Fried_Guy (edited 02-11-2002).]