I installed an aftermarket coolant temp gauge on my 2003 Toyota Echo since new. Recently I noticed the reading on the coolant garage would fluctuate up and down about 5 degrees Fahrenheit when the engine reached the optimal operating temp (I.e. Car has been driven for at least Half hour). It does not fluctuate when the temp is still continuing climbing.
What are the possible causes? I flushed the radiator by myself. Air in the cooling system? Early sign of a blown head gasket? The engine has 146K miles.
What are the possible causes? I flushed the radiator by myself. Air in the cooling system? Early sign of a blown head gasket? The engine has 146K miles.
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