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Q: My 2004 elantra's heating system is blowing cold air -overheating smoking -filled collant refilled still overheating /smoking -wha

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Heater now blowing cold air --car engine overheating /smoking-will not cool down. Filled up tank with coolant -took short drive --same as before overheating -no heating - What could be the problem ? 2004 elantre

My car has 157000 miles.
My car has an automatic transmission.

Hello. Overheating can be caused by many things. The first thing I would do is make sure that the system is properly filled and bled. If there is any air bubbles in the system, or the system is low on coolant that may be what is causing the vents to blow only cold air. Once the system is properly filled and bled, the next things I would look at are the heater control valve. In regards to the smoke, if the smoke is from the engine bay, it may be due to a coolant leak, if it is coming form the tailpipe it may be a sign of a more serious issue - a blown head gasket. I’d have an expert diagnose the overheating problem in person in order to get this addressed sooner rather than later.

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