engine temp

hey guys.
My engine temp gauge is reading 40 degrees too hot in new my new motor, worked fine in the old on. Luckily i put a couple of meat thermometers in the Radiator before i took any apart and everything heated and opened dead on.
The sender mounted a bit different, (inner set of threads).
any ideas

Shafe

 

New motors tend to run a little hotter untill they break in a little. Drive it a little more and see if the temps come down some. When you shut the motor off wait and see if the radiator overflows, if it doesn't then keep driving it untill it breaks in a little more.

 

My motor ran 180 from the first after rebuild and never moves. I had a three core radiator built for it. I am a big fan (no pun intended) of radiators being big enough to let the thermostat thermostat.

 

thanks for the ideas guys. but,, its not running hot...for some reason my gauge is off by 40 degrees, and it was fine in the old motor... I know a new gauge is easy but it kinda buggs me...lesson learned though dont always blindly check the gauge..
Shafe

 

Food for thought, You said the sender mounted a little different. If the sending unit is positioned to where its not sufficiently exposed to coolant flow it could give an off reading, An example would be if a bushing/reducer was used and there was very little surface area exposed radially inside the bushing ( bushing nearly touching sender ). Could be wrong but I was under the impression that this could cause off readings.

The three engines that I have broken in were all were spot on the T-Stat from the get-go.

This may sound silly but could the T-Stat be in backwards?

The solution may have been posted by Patrick while is was typing , I was thinking running hot (-:

 

If you know the gauge is now wrong, I would guess this problem is electrical. The sender must be well-grounded through its base. If you used a lot of teflon tape or have somehow interrupted the ground, the reading could be way off. The "sending" unit is really a variable resistor (thermistor) that changes its resistance based on temperature. Add a resistance elsewhere in the circuit, due to bad connections or whatever, and the reading will shift in proportion to the added resistance.

I'd also check the connections. The sender has a spec - a resistance - at a specific temperature. If you can't verify that spec, then the sender is broken. I'd measure the resistance in situ, from the terminal to the battery ground and from the terminal to the sender case, and see if the reading is the same. If not, your sender is not grounded properly. If it is, and the spec is off, you need a new sender.

It's also possible that the gauge has broken, but test the sender first.

hth!