The temperature needle on the dashboard keeps going up if I am going between 10 and 20 mph. If I maintain 30 mph or over, temp remains normal. When stopped for a prolonged period of time with the engine running, or said 10-20 mph, needle climbs up. I have been checking coolant fluid reservoir at a normal level. Haven't seen steam or boiling liquid yet.
My car has 180025 miles.
My car has an automatic transmission.
This problem is not from a thermostat but the radiator not cooling the coolant at lower speeds. This can be from the radiator being clogged, or the cooling fans not working correctly and coming on at the correct time or not at all. Check that the fans are coming on first. If you need help with this, a certified technician from YourMechanic can come to your location to diagnose the overheating issue correctly.
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