Temp gauge reading low

[Ramiro0727]

Just recently finished installing a rebuilt SBC 350 with aluminum heads. I re-wired the whole truck from front to back. I noticied that the temp gauge reads low. At first the temp gauge was pegged all the way to hot. I grounded the bottom terminal on the temp gauge and the gauge started working but it reads low. Could the temp sensor be bad or the temp gauge is bad? The temp gauge is brand new.

Thanks,
Ramiro

[my56chevytruck]

I'm thinking the sensor and gauge are not compatable. Where is the sensor mounted and did it come with the temp gauge?

[74baggedbug]

Trace the wire from the sensor to the gauge.. make sure it's not grounding out somewhere

[Ramiro0727]

Originally Posted by my56chevytruck

I'm thinking the sensor and gauge are not compatable. Where is the sensor mounted and did it come with the temp gauge?

My56chevytruck the sensor is mounted on the drivers side on the block of the engine

[Ramiro0727]

Originally Posted by 74baggedbug

Trace the wire from the sensor to the gauge.. make sure it's not grounding out somewhere

74baggedbug I will trace the wire from the cluster to the gauge to make sure its not grounded. It's a new wire I added when I re-did my dash cluster plug.

[my56chevytruck]

The mounting is correct but is that sensor and gauge compatable? In other words, did they come together as a unit? Also, like others have said, check the grounding. Any possibility you have another gauge you can hook up to check against this one?? Nice engine.

[RGT]

What temp. thermostat do you have in the engine? Maybe it is reading correct, mine only sits a little to the right of that second line and never points straight up and down even on a hot day...

[Ramiro0727]

Originally Posted by my56chevytruck

The mounting is correct but is that sensor and gauge compatable? In other words, did they come together as a unit? Also, like others have said, check the grounding. Any possibility you have another gauge you can hook up to check against this one?? Nice engine.

My56chevytruck I bought the sensor from our local parts store. The gauge I got at Brothers truck. I still have the old gauge I replaced with the new one. Than you. Here is a better pic of the engine.

[Ramiro0727]

Originally Posted by RGT

What temp. thermostat do you have in the engine? Maybe it is reading correct, mine only sits a little to the right of that second line and never points straight up and down even on a hot day...

RGT not sure what temp thermostat my son put in it. When it really warms up it gets to about the 2nd line. Also the sensor for his electric fan is 180 degrees and the fan turns off when it gets to 160 degrees.

[davepl]

I believe the original is Delco #G1852, so anything compatible with that should work.

Standard Motor Products TS6 or TS6T
Airtext 1T1053

Do you have a part number for the sensor you used? I can check to see if it's compatible with the factory gauge just to make sure.

[garyd1961]

Looks about right for these trucks. Mine ran about the same with a 180 thermostat. Back in the day most every one of these trucks I rode in ran about the same.
I put a 195 thermostat in mine and now it runs a little to the right of the first mark but I'm running a vortec engine which was meant to run a 195. I may just go back to the 180 for the summer though.

[chevy72blu]

Looks about right to me? Every one of these trucks I've owned will read right at that line or close to it. My LS has I believe a 180* stat (fans kick on at 200) and its verified by my OBD2 scanner right next to the gauge (just to the right of the line).

Check your T-stat. You may have a 165* or something and its reading correctly.

Also, its not like these gauges provide much info. So long as you know what is normal - and can tell if its overheating, the gauge is doing its job IMO.

[Ramiro0727]

I asked my son about the thermostat. He can't remember temp the thermostat is rated for. I'll assume everything is fine with his temp gauge where it reading. Than you all for your help.

Ramiro