Temperature sending unit, need help
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 876
Likes: 1
From: Same as our leaders Out of my mind
Temperature sending unit, need help
My new motor runs great, and it does not over heat either, I have checked the engine temps at the thermostat housing and at the cylinder head with an I.R. temp. gun, max readings after a hard highway run are 218 at the thermostat and 225 at the cylinder head. My problem is that the dash gauge is reading almost 50* higher than the actual engine temperature. Is there a specific temperature sending unit that I need? It's a 79 L-82 with a 383 stroker that only has 125 miles on it. We tested the gauge function and it is pretty close to where it should be, then we tested the (new) temp. sending unit and found lower than expected resistance. This is not the first sending unit I have tried, that is why I am thinking I must have the wrong sending unit. Anyone have a part number or a lead on the "right" sending unit? Thanks in advance for your replies! 
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Can't help with a number but you are on the right track. Many sending units out there only a few are correct. I had to use a smaller sending unit in my heads and my gauge is off about 10 to 15 degrees. One of the vendors or suppliers of harnesses has the correct one. I don't remember which one.
Burning Brakes
Joined: Oct 2002
Posts: 914
Likes: 14
From: Aberdeen, Scotland
The right part
Try www.lectriclimited.com. They have a correct unit I think. I got a sending unit from Rogers Corvette clocks... works, but I think its off by ~ 15-20 degrees?
Might also be the gauge... you can check this too. Boil water and check it. Its a pain though.
carbster
Might also be the gauge... you can check this too. Boil water and check it. Its a pain though.
carbster
Thread Starter
Burning Brakes
Joined: Jan 2006
Posts: 876
Likes: 1
From: Same as our leaders Out of my mind
10 or 15 degrees of variance is acceptable to me, mine is off by 40 to 50 degrees. Thanks for the leads, I'll keep after this one until it is fixed. I have all of my stock gauges in working order with the exception of this one.
