///MIKE

I was able to take a video of the noise while it was happening.

Car is a 1990 300zx with 61000 miles. Noise was apparent at about 2500 rpms.

Noise was going on when I pulled the car into my garage... I got the video, and then turned the car off. Turned the car back on 2 minutes later and I can't get it to duplicate. Was a lifter stuck or something?

I just changed the oil. Used Rotella T6 5w40. Is that too thin of oil.

Please chime in! Call me a retard need be... any ideas?

Thanks in advance!

///MIKE

Car will only make the noise when engine is warm. Found a thread on these forums with a similar issue. No solution / remedy posted though. Sounds like a stuck lifter or something.

PredatorZ

Try a can of Marvel Mystery Oil, it will clean things up inside, you might have sludge in your internals, might do an oil change and try a synthetic possibly to see if that helps, might take up to a week of daily driving before you see a change in the noise. Worth a shot as opposed to tearing it apart and servicing the Lifters.

///MIKE

Thanks for the response! Yeah, I found a couple more videos with the same noise. Consensus is lifter noise. I went over to Walmart on lunch break and got some STP oil treatment. I'll see if that makes a difference and report back.

///MIKE

Ok, the STP helped. I ran it for awhile and then changed the oil to a 10w30 mobil 1. The fresh oil I'd put in was jet black... so I guess the STP really started to clean the engine out.

I also added about 3/4 quart Marvel Mystery Oil. Car seems to have quieted down quite a bit. Still has a mild tick / knock at about 1500 rpms when winding down... we'll see if it goes away. Definitely a lifter issue. No doubt about it.

Oh, I also passed all of the oil removed through a extremely strong set of magnets. I also drained it into a very clean oil pan. Zero shavings or anything... Definitely lifters... but good piece of mind that it's not something else.

borini63

I used seafoam and that took car of it!