I have a 1988 sport coupe (5.0) and recently had my thermostat replaced because my temp gauge was constantly going too high, and it seemed fine after that. Now it seems to be doing that again and I recently did "overheat" and blew a heater core hose, so I replaced both of those. It does seem to be going high still, but will then go back down and stay just above the halfway mark. What would cause this ? I would think it should stay halfway or lower ?
Sounds like an air pocket
I had Tue exact same thing happen. I ended up blaming it on the irv (internal voltage regulator) because of.my gas gauge also reading too high.
Could be a bad fan clutch - this will cause hot running at around-town speeds and normal temps at high speeds. Could be a bad radiator core, either plugged or the fins rotted out - this will cause the opposite (hot on the highway, cooling down around town).
That's exactly what it sounds like...if I drive slow it heats up more than at higher speeds. Tonight however it was staying in the normal (middle).
mine is also a 88 sport 5.0 but mine is always normally close to hot
i had for awhile it was running pretty hot but i had gotten the oil pump change and when the guy lifted the motor to change it he crushed a plastic piece on a hose near the rear of the motor.think it was some aftermarket fill or flush cap.neways it barely leaked some but it cause it to run really hot til i changed it so maybe u need to make sure u dont have any leaks at all.
Well the past two days or so it's been running normal...might go a little close to hot (about 3/4 of the way up) but then goes back down to the middle or less. Not sure what's up but I think the gauge is quirky
could be.i know my oil pressure gauge doesnt always work right