At idle, on hot days (90+) after about a minute, the A/C cuts out and the temp gauge begins to rise. Gets about 3/4 of the way to the red zone, but never reaches it. I changed radiator cap, but still does it. Fluid level is fine; no coolant leaks that I can see. Called a mechanic and asked about a radiator flush. He said he’d do one, but it probably wouldn’t help and I should just bring it in for a diagnostic. Any other suggestions? Thanks much.
Make sure the fans are running.
Has your coolant been serviced on schedule?
I would do that, and replace the thermostat
Post back with results, please
I’m taking it in by week’s end. We’ll see what they say. But, yes, the fan’s working. Replaced it last summer.
Overheats at idle but runs fine at hwy speed? U can check coolant level? Don’t know your mechanical ability.
Yep runs fine (normal engine temp and AC running cold) at highway speeds. It’s only at stop lights, or more likely, in stop and go traffic, that the temp begins to rise and AC begins to cycle off. Coolant level is fine, but I’m going to have it flushed see if that’ll help.
I have an '01 Sequoia and my motor uses a clutched fan driven by the drive belt on the motor side of the radiator, and an electric fan on the other side (between grille and radiator) of the radiator. The electric fan goes on with the AC, the drive belt driven fan spins with the motor.
I suspect the belt driven fan may have a bad clutch, or that the shroud directing airflow might be damaged or missing. If this mechanical fan isn’t working properly you will have overheating when the truck is sitting still. When the truck is moving natural airflow moves enough air to effectively cool the motor.
So I think we finally have it licked. After replacing the electric fan, flushing the radiator and then replacing the radiator altogether, supposedly the overheating issue is resolved. We’ll know when my wife is in the carpool line Monday picking the kids up from school. The fan clutch was replaced in 2011, and even though one mechanic a few weeks ago told me that that would solve it all, turns out the clutch was working fine.