News: Interesting observation. . .anyone else have this happen?

[Bolisk]

Since I bought by '70, the temp gague has never read correctly. It always read 140 when the car was fully warmed up. I have sense repladed every part of the cooling system except for the wireing harness and the temp gauge. Sill only reads 140 when fully warmed up. When the engine is cold, the needle is way below the 100 on the dial.

For x-mas, my wife bought be an IR temp gun, and I was able to confirm that the engine seems to be running arround 187-215 when fully warmed up.

Yesterday, on the way home, I drove over a plastic bag, and I immedately became concerned that it was sucked up agains the radiator because I didn't see the bag in my rear view mirror. Sure enough I saw the engine temp climb up over 155 on the gauge. . .then right on upto arround 180. An appearent increase of about 40 degrees. Using the numbers from the IR temp gun, that would put me arround 255 in the worse case scenario. YIKES!

I nursed the car home. . .and pulled it into the garage. I left the car running because I wanted to see what the acutal temp of the car was using the IR temp gun. I opened the hood. . .only to find that there was no plastic bag in the radiator. . .or anywhere that I could find. . .but the needle on the gague was still reading ~180. I immedaitly took the cars temp. . .and was supprised to find that the car was actually runing at 187!! The needle now appears to be reading correctly!!!

This morning, when I walked past the car, I noticed that the temp gague (after a full nite's cooling) now reads 100, the needle does not fall below the 100 on the dial anymore.

Is it possible that my gague fixed itself?!?!?! Anyone ever see anything like this?!?!? Where should the needle point with the car is fully cooled off (at 100, or below)?!?!?

Regards,
Bolisk

 

[73shark]

Or maybe the sensor has gone bad.

 

[Bolisk]

Yeah. . .but in a good way! :L

 

[ducvw2004]

The stock oil pressure guage in my 81 reads random pressures all of the time!
The previous owner installed an after market gauge, which wiorks fine, so its a total mystery to me why the stock gauge does anything at all!

 

[Rebelrob]

Haaa, yep, having the same sort of problem with my fuel guage, one minute its full the next its empty or half full, I think the moon has something to do with it.
where are you taking the temp reading with this IR Temp gun?

 

[Mr. Chuck]

Temperature Gage TroubleShooting

Since I bought by '70, the temp gague has never read correctly. It always read 140 when the car was fully warmed up. I have sense repladed every part of the cooling system except for the wireing harness and the temp gauge. Sill only reads 140 when fully warmed up. When the engine is cold, the needle is way below the 100 on the dial.

For x-mas, my wife bought be an IR temp gun, and I was able to confirm that the engine seems to be running arround 187-215 when fully warmed up.

Yesterday, on the way home, I drove over a plastic bag, and I immedately became concerned that it was sucked up agains the radiator because I didn't see the bag in my rear view mirror. Sure enough I saw the engine temp climb up over 155 on the gauge. . .then right on upto arround 180. An appearent increase of about 40 degrees. Using the numbers from the IR temp gun, that would put me arround 255 in the worse case scenario. YIKES!

I nursed the car home. . .and pulled it into the garage. I left the car running because I wanted to see what the acutal temp of the car was using the IR temp gun. I opened the hood. . .only to find that there was no plastic bag in the radiator. . .or anywhere that I could find. . .but the needle on the gague was still reading ~180. I immedaitly took the cars temp. . .and was supprised to find that the car was actually runing at 187!! The needle now appears to be reading correctly!!!

This morning, when I walked past the car, I noticed that the temp gague (after a full nite's cooling) now reads 100, the needle does not fall below the 100 on the dial anymore.

Is it possible that my gague fixed itself?!?!?! Anyone ever see anything like this?!?!? Where should the needle point with the car is fully cooled off (at 100, or below)?!?!?

Regards,
Bolisk

Had a similar problem; found bad connection at the bulkhead connector (C115) located on the engine side firewall, driver side, outboard of the brake master cylinder / boost unit. You need to make sure to disconnect battery negative cable before pulling the connector apart. Once open look for signs of corrosion, water, oil contamination, etc. Mine came from the times I would gunk the engine to clean-up oil / steering fluid blow back.
Once you remove the cause of the problem with a spray contact cleaner (one that doesn't leave any residue) and/or compressed air, heat gun to insure connector is dry, you need to insure the connector is undamaged and properly aligned when you replace / reconnect it. I applied new sealant (RTV) around (360deg) the sides, once I verified everything was working correctly.
Hope this helps!!

 

[Hib Halverson]

the gauge didn't "fix" itself.

The car is nearly 40 years old. Replace the temperature gauge. My guess is that there's a problem with its movement.