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Toyota Repair/2004 Toyota Sienna LE Running Hot


I have a 2004 Toyota Sienna LE with 155k miles.

I've had the van for ~4 months and the temp gauge, when I'd previously noted it, always hung around the halfway point on the gauge. A few days ago I noticed it was running at the 3/4 point and creeping up toward the red zone.

I turned on the heat to drain off some of the heat in the engine compartment and got to an AutoZone. Checked the coolant. It was very low so I filled it up.

The car still runs hot.

The coolant level hasn't dropped and there's no water evident in my oil so I don't think it's a head gasket issue.

Based on research I've done, it looks like that leaves the thermostat, cooling fan, and water pump as likely culprits. Are there any others?

And is there some way I can narrow the problem down? Some way I can test to see if it's specifically the thermostat or cooling fan or water pump or whatever?

Or is it time to take it to a mechanic?

Thanks, Mike

Hello, the water pump would be last on the list, the thermostat would be first. Check the cooling fan, it should turn on when the engine gets to just over halfway on the gauge, if the fan works try replacing the thermostat, if it still overheats it may need a new radiator.

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