Temp gauge reading low...

[GsxrMike]

I have the coolant temp gauge on the back of the intake manifold (350) by the dizzy and it only reads about 130*F. I took the temp with an infared thermometer the other day and I was reading right around 180*F around the t'stat housing. I bought a new guage but I havn't put it on yet. My question is; is there any reason the spot on the back of the manifold would read any different than the spot up by the thermostat? I was planning on putting the new guage up by the t'stat housing because thats where I am used to seeing them but I don't know if I should do that or put it back in the back. I guess I may try putting it in the back first and if it is still reading low I will move it up to the front. Any input? tia

 

[apache]

Every time Ive taken temp reads they tended to be hotter in back on the block , such as the head,mani, etc. Trying to get a good water temp read in back seems hard to do due to the lack of closeness to actual coolant and it seems even the fans cooler air flow affects the reads some. Up front the top of the thermo housing seems to give the closest reads to what things should be per the thermo but even at that it varies. Example is a 180 thermo and the housing is more like 190+ the 200 + in back by the manifold passages. Theses were probably taken off mostly Cummins 6 bangers and some toyota 22R`s.

 

[dyeager535]

The intake doesn't have water running back there AFAIK, which is probably why it was reading cold, although I can't explain why an infrared would show a surface temp higher.

Have you tried it in the head, or can you not put it there?

 

[GsxrMike]

Alright guys I put in a new gauge and it is reading 190*F now so I think I am good. I put it in the same spot on the intake. It is right next to the dizzy on the passenger side.