So I had my car at the mechanics because my head gasket had blown and I had a used engine put in. The Mechanic swapped the engine and a few days later I had the flickering oil pressure light when sitting at idle. Mechanic replaced the pressure sensor and said good to go. On the way home same issue. Long story short 4 engines later mechanic gives up refunds my money. He told me the last engine was only supposed to have 90k miles on it and only 5 PSI @ warm idle. He never checked oil pump or any thing else just kept swapping engines. Where would be a good place to start to diagnose this issue. Could it be a leak or the regulator valve causing this. Engine is quiet with no knocks and runs great(I take it around the block once or twice a week just so it is not sitting). Thank you for any help you can provide I love this car and need to get it back up and running.

 

I had a similar problem in my third gen, when I swaped an engine. The oil pan was dented so it did not let the pick up suck up enough oil. I took the pan off and banged out the dent and it worked as it should. Not sure if that's your problem but I thought I would throw that out. Have you thought about hooking up an oil pressure gauge to make sure you idiot light is correct? You could have "crap" built up in the pressure sender causing a false reading. Good luck with it.

*When the oil light flickers does it sound like the car has low oil pressure? i.e. starting to hear valvetrain chatter

 

The chances of finding 4 used VQ engines with low oil pressure are extremely low, actually almost unheard of. That fact implies that your mechanic definitely didn't swap 4 engines, he just attempted to fix the situation by replacing the oil pressure sensor.

My suggestion would be to find another mechanic and start from scratch. You claimed he refunded your money so your back at $0.00 once again.

 

did your try putting in new oil? if you dont hear any weird noises like valve train chattering or anything like that then you should be ok.

 

249,000 miles later, still have timing chain rattle and timing cover leak and i was told like 4-5 years ago that i have no oil pressure at all. i replaced the oil sending unit/switch which gets clogged and i still have an occasional light flicker. oh well

 

No noise. No chatter, rattle, knock nothing. Oil level is good. May change the oil sending unit and the oil and see what happens if I go back to driving it.

 

By any chance do you know where he was taping into the oil system to check oil pressure?

Was he removing the oil pressure sensor and using an adaptor and a mechanical oil pressure gauge.

 

Not sure. By the time I picked it up from him I was quite frustrated at his quality of work. I assumed he was but can't say for certain. Could this make a difference?

 

So you spent for the swapping out of 4 engines?

 

No I had a parts and labor warranty from him on the engines so it was at his expense. Don't know why he didn't bother to troubleshoot any of them and just kept trying to change them. The last time he had the car he told me he couldn't find an engine and he was going to replace all the bearings. After a month and a half of calling and checking he told me all the parts had come in and he replaced the bearings and still the problem persisted, however when I went to pick the car up from him because he had given up he said that was not what he had done and that he had just changed the engine yet again. I am going to have an actual pressure test done and see what is really going on with it.