Q: Loud knocking/tapping from driver side of engine.

asked by on January 19, 2017

Loud engine knock/tapping. Decreased oil pressure (~20psi) and rpm's (~500) at idle. Idles rough and decreased power while accelerating. Knocking/tapping never goes away. Instrument panel displays "service stabilitrac" & "traction control off", check engine light is on. Extremely low oil, but no low oil light ever came on.

Historty - The exact same thing happened at 85k miles and at that time mechanic checked misfiring cylinder, fouled plugged, determined blown ring. Replaced engine with used engine. Have not checked plugs yet.

Does this sound like a ring or lifter? Aware of GM AFM issues, oil consumption, and lifter issue history. Rebuild or replace? Has anyone used drivetraindirect.com before?

My car has 108000 miles.
My car has an automatic transmission.

It would be difficult to determine the exact cause of this issue without physically inspecting the vehicle. However, I can recommend that if it is possible for you, I would replace the engine with another new or rebuilt engine and then have the engine you currently have rebuilt. Once your engine is rebuilt you can sell it and get some of your money back for the new engine. If it is not possible to do both, I would recommend having the engine inspected by a qualified professional to determine if rebuilding is possible and which option would be the most cost efficient.

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