Q: Low engine compression

asked by on May 01, 2017

I had an engine compression test done today. Three cylinders are at 75 psi and one is at 165. The car does not misfire though and no check engine lights. It seems to drive fine at the moment. Another shop who checked my transmission last week and test drive didn't mention it either. I realize the engine could fail at any moment but it seems to be running pretty well for being so poor. Trying to figure what to make of this.

My car has 159000 miles.
My car has an automatic transmission.

Hello, thank you for writing in. There are several components that wear down and can cause low compression. Considering three out of four cylinders have low compression, you may have worn piston rings and need a major overhal. Other main causes of low compression are worn exhaust and intake valves, a blown head gasket. With that being said, you can check for coolant mixing with your oil in the case of the blown head gasket. If the engine does need a major overhaul, consider the cost of the vehicle and the price of a new engine to compare the to cost of an overhaul. For more help with repairs, contact our service department to schedule an appointment.

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