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Q: Blows smoke tailpipe startup

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My truck runs really good and doesn't give me any problems. But it started to blow smoke out of the tailpipe when I start it up. It’s only happened 3 times. It doesn't get hot, doesn’t eat oil or miss. It only happened at startup. Is there something wrong with my truck? Could this be a sign of something going wrong?

Hello there, thank for writing in about your 2005 GMC Canyon. This is a common problem as vehicles age and go up in mileage. The fault determines what color the smoke is and how it looks. If the smoke is black, then this is generally from oil. Oil can enter the exhaust from faulty valve stem seals or failing piston rings. If the smoke is white and smells slightly sweet, than it is likely coolant. If coolant is burning in the exhaust, the most common cause would be the head gasket.

If you need to have this looked into further, a certified technician from YourMechanic can come to your car’s location to diagnose the smoke and perform the appropriate repairs to resolve this.

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