Q: Found out 1st cylinder in car has no compression....what are my options?

asked by on September 05, 2016

Engine light came on one day after not driving vehicle for a week. Took it to Meineke who did compression check and found first cylinder has no compression all others are fine. Question is what are my options as far as fixing my vehicle. codes that came from diagnostic tool is P0300-0302 and p0171 for gas mixture too lean

The first thing you have to do is confirm such a diagnosis by getting a second opinion. It is unusual for three cylinders to be perfectly normal and one to have "no" compression. Nevertheless, it is possible.

A cylinder can fail to seal and then fail to develop compression due to the following defects: 1) a leaking head gasket; 2) a stuck valve; 3) a burnt valve; 4) a damaged valve seat; 5) a piston ring issue; 5) an engine timing belt mispositioned (unlikely if 3 cylinders are good).

All of these defects require possible but substantial repairs. You first have to confirm that you indeed have low compression unless you are very, very confident that all test were done competently. Mechanics are like medical doctors, they can make mistakes even with the best of intentions. To have the correct fixes pinpointed, have a second expert, like one from YourMechanic, come to your car’s location to inspect the Check Engine Light codes in more depth and help you with a repair.

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