Another overheating thread

[mindcrash]

Apologies for my absence.

I have given up and took her to the shop that did the head gasket.

Got a call from them today that they agree she’s running hot but can’t pinpoint why.

Words were said that “this just might be the new baseline” when they called me today which i can’t accept.

Either way they’re going to keep testing and will be in touch. My hunch is the head gasket repair wasn’t done correctly unless it’s something worse

 

[MissahPapaJ]

You could always get another sensor and test resistance at 220 degrees and compare OHMs not 100% accurate way to do it but there are OHM specs for temp sensors and you could see if they have different specs. I’d bet a calibrated meat thermometer and a pot of hot water can tell you a lot. What brand of temp sensor did you get? I’ve gotten parts that were out of spec or didn’t work ( even OE although more rare )

 

[alia176]

You could always get another sensor and test resistance at 220 degrees and compare OHMs not 100% accurate way to do it but there are OHM specs for temp sensors and you could see if they have different specs. I’d bet a calibrated meat thermometer and a pot of hot water can tell you a lot. What brand of temp sensor did you get? I’ve gotten parts that were out of spec or didn’t work ( even OE although more rare )

sounds like his mechanic has his 80, and they're not able to find the cause of the overheating. Curious to see how this issue gets resolved.

 

[Marco Lau]

I don't understand why people would continue to run AC when you already know running AC in your system will at the very min. adding 10 degree to your existing cooling system. If you see 220F on highway, without climbing grade with AC, Turn off the AC and I would blast heat for the rest of your trip and try to avoid any sort of grade climb. The 80s do not have a dedicated AC condenser fan, so you are relying on the fan clutch and moving air to compensate for the added heat, which isn't ideal. 230F on a 1FZ, you are knocking on door welcoming a new head gasket...187F is normal operating temp and about 195F with AC running. 220F on highway with or without AC, i bet you have a bad radiator, a clogged cat or coolant or oil cooler blockage. It has happened to me before, turned out it was a bad radiator, the second time. it was a clogged oil cooler for the transmission. You want to make sure you cooling system is at tip top shape before you go down this path.....

 

[MissahPapaJ]

@Marco Lau
Sage advice, if I’m climbing a known grade I open the windows and turn on the heater 1/4 mile prior to the climb. Also I have a throttle lock so after working her hard I’ll use the throttle lock like a manual turbo timer and set the vehicle to 1800 RPM and turn the heater on high and get out then I let it drop to the lowest temp reading on my scan gauge for one minute before I shut it off, It’s the little things. A/C is a strain on the system and a few mins of discomfort isn’t as bad as refreshing a head gasket or worse.

 

[Broski]

If the system is working correctly, AC shouldn’t be a problem.

 

[Marvelicious]

If the system is working correctly, AC shouldn’t be a problem.

I admit, I don't live in the hottest part of the country, but I do sometimes wind up in the high altitude desert in the middle of summer, and I can't imagine accepting anything around 220 as a "new baseline". I have occasionally turned off AC for a long hill climb because of power, but never because of heat.

 

[landtank]

Curios what brand HG they used. If you left it up to them it was likely the cheapest off the shelf they could find.