My car has a temp sensor for the gauge in the right head and the stock sensor for the computer and fans in the left head. They have always been within three degrees but all of a sudden my gauge has been reading between 15 and 20 degrees hotter. It was spiking up into the 250 range but that stopped when I put a new thermostat on, it now reads steady but consistently hot. The stock sender reads roughly 190 and the gauge sender reads 205-210 when just driving around. The change similarly but the right side is always hotter, or has been for the last week or so now. I've verified temps with an infared temp probe and the right side sender is definitely hotter, I've also tried putting in a new sender just to check and it reads within 2 degrees of the old one (still hot.)

Engine is a 2001 out of a camaro with ~70,000 miles, coolant looks clean, all maintenance done regularly. I've owned it since the engine had 38,000 miles and it's just now starting to act up, still runs great but mileage has dropped just a tad, no strange noises and the stock sender still reads normally.

Any ideas? I'm pretty much stumped. Thanks for the help in advance.

 

do you have catalytic converters ?

 

Just jumping in are you getting at maybe a cat is clogged up causeing one head to running slightly hotter then the other?

 

thats correct

 

before you do more research, measure with a laser/Ir temperature tool. measure the heads when it's running. check right and left head.

 

I only have a single cat placed after the exhaust comes together. I also just failed emissions due to high nox so that's a good option right now.

I did measure with a laser/IR temp probe, I measured right on the senders and verified the readings are correct.

Edit: I'll also measure and post reading from the front and back of each head just for more info. Thanks for the ideas so far.

 

Okay, it was hard to get a reading at the back of each head due to space restrictions but after driving for 15 minutes the temp on the dash was stable at 200 and the left head was showing 172 and the right was 188 measured with a IR probe at the front surface of both heads. Like I said before I only have the one cat but if you guys still think it's a cat I'll get one changed out but I'd rather not blow a couple hundred bucks when it's something else.