Engine is missing

[mrzzzr1]

My LT5 moter started missing badly recently.

Sometimes only after warm up.

Other times right from a cold start. When missing engine lopes badly at idle and makes a knock sound but only at idle. My mechanic has some LT5 motor experience and thinks the knock at idle is the dual mass flywheel making noise due to the way the engine lopes due to missing. It only makes this sound when it is missing/running badly.

Sometimes it is running smoothly with no apparent problem.

Oil pressure drops near zero sometimes at idle but reads near 80 on the highway. We originally thought it might just be a bad oil sending unit but now I am starting to get worried.

Any thoughts or suggestions would be appreciated.