Aftermarket water temp gauge reads low due to wire length

eastfizz wrote:
I do not know what your altitude is, or how you are testing the gauge, however when I was testing a trans fluid temperature gauge with boiling water, it was reading about 200 degrees F when the water boiled. I thought the gauge might be bad or the wire was not large enough for the run to the trans from the gauge. After some checking, I determined the gauge was correct as water boils at about 200 degrees F at my altitude, 7100 ft. Hope this is helpful.

Best regards,

Lowell

7100 eh? I've got 2900 on ya:p Dunno if altitude is the issue or not but it might very well be.

I do not know what your altitude is, or how you are testing the gauge, however when I was testing a trans fluid temperature gauge with boiling water, it was reading about 200 degrees F when the water boiled. I thought the gauge might be bad or the wire was not large enough for the run to the trans from the gauge. After some checking, I determined the gauge was correct as water boils at about 200 degrees F at my altitude, 7100 ft. Hope this is helpful.

Best regards,

Lowell

The sensor is the threaded sensor.

On the intake manifold for my engine(440 Mopar) there are half a dozen ports it could screw into for the various CTO systems that engine used in various car/truck/non-MH configurations.

What type of sensor are you using? I see on their webpage, a threaded sensor, which would typically go in the head or intake, and I also see one that is made to go on one of the rubber hoses. You state that the 2 sensors are as close to each other as possible. Does this mean you have 2 sensors mounted on a hose?

You may be able to correct it but the trouble is quite likely not the extension wire. The engineer at Isspro told me for my pyrometer adding 40' of small 22-26ga wire would make such a slight difference in the reading it would be hard to measure.

Jim

The new gauge is a digital GlowShift
http://www.glowshiftdirect.com/productimages/2010-blue-digital-gauges/thumbs/13_GS_BD_Water_Temp_Thumb.jpg

There is a mechanical gauge on the engine and the new probe is as close to the old one as I could get it.

It's funny because with the engine off and cold the new gauge is only 1*F off from the old one. The engine isn't close to overheating but I'm just curious as to whether or not this issue can be corrected or not.

How did you determine that the gauge reading was 10 degrees off? When I replaced my temp prob it seemed to run hotter than the OEM prob. It bothered me for a while because the fan clutch seemed to come on much later. I decided to shoot the prob itself and the surrounding area with an IR gun. The readings were 15 degrees lower than what my dash gauge was reading. Also shot the thermostat housing it was also 15 degrees lower than the gauge reading.

I'm confused, how do you know it's 10 degrees off
and why would you care. If your that close to overtemping you have another problem

I would suggest that induced voltages would be more likely to cause the display to be erratic, rather than just off by 10 degrees.

I am curious what type and brand of electronic gauge you are using. I just put an electronic gauge on mine and it reads about 10 degrees high. Really don't know if it is the fault of the gauge or the location on the engine compared to the one on my ECM, or maybe both.

If you are using a thermocouple, shouldn't you be using thermocouple wire? Length should not be an issue due to the low current/voltage involved. Induced voltages could be an issue with longer runs.

Carl