Hi all,
I have a 97 ES300 (238K miles) that just started overheating. First thing I checked was coolant, and the reservoir was empty. I filled it up and topped off the radiator. It took about a cup, I guess. Since then (six days) it has not leaked any coolant, but it still runs hot. It takes about 20 minutes for the gauge to get to the 50% mark. It holds near the 50% mark on the highway, but climbs over it in stop-and-go traffic. I suspect it might climb over the 50% at full speed if I drove it long enough.
I checked the radiator fans when the gauge was reading > 50% and they were not turning. However, they run just fine when I turn on the A.C.
I replaced the coolant temperature sensor. There appear to be two sensors, but the computer at my auto parts store only listed one, and that's the one I replaced. Both are near the radiator fill. Also, the Haynes manual only mentions one sensor.
I checked the No 1 fan, No 2 fan, No 3 fan, and main relays for continuity exactly as described in the Haynes manual and they all passed. Can't say that I understand the check because Haynes says there should be continuity across the switch with no voltage across the coil, and continuity when voltage is applied across the coil. That seems backwards to me because the normal operating condition of the fan is off. But they are all that way.
Any ideas would be greatly appreciated.
Thanks.
