Q: Blown Head gasket or just overfilled transmission fluid?

asked by on February 07, 2017

Recently my car tore apart its serpentine belt and I had to change that out. I had to drive a little without the belt to get home. After the belt was fixed I put a lot of Transmission fluid in the car, and now it is blowing smoke out of the exhaust. Is this from the head gasket or the transmission​ fluid? I recently filled the coolant and it doesn't look like it has any loss to it.

My car has 139219 miles.
My car has an automatic transmission.

Hi There, Transmission fluid should not have any impact on any smoke coming out of the exhaust. Chances are, if you drove the vehicle without the serpentine belt for any distance, the motor would have overheated to a critical point causing a blown head gasket as you have indicated. This would cause a white smoke to come from the exhaust and eventually cause the motor to heat up to a point where it will no longer run. I would suggest having an expert from YourMechanic come to your location to diagnose and inspect your car.

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