So my father in law bought a 99 Park Avenue with 70K on it and its fully loaded. Great looker and ran perfect for the last week he owned it till he started up and it sounds like all his lifters are banging to me. I looked in the oil cap and couldn't see oil moving thru there on the valve springs, not sure what happened here as I know that these oil pumps I thought are bullet proof pretty much. He ran the car around all day doing errons and than a few hours of it being shut off, he started it to this and I changed the oil out after looking at his dipstick which was full. I seen nothing in the oil, but it was dark and the sticker said he has a 1,000 left on it. But the oil was older according to the change date. I also ran a cleaner in the car before dropping new oil into it with zero luck.

Also the digital oil sender/signal is jumping up and down. With the old oil in it, it was going down to 25-40. Seems better with newer oil, but noise has not reduced at all.

Please help..... I need to know if I should start by taking the oil pan off to look at pick up tube or if you think the pump is shot?

Thanks
Conrad

Heres a video of it

Check the oil filter. Some have been known to come apart and block flow. Although if you did a change..you probably changed that.

Then I'd be pulling the oil filter adapter and checking that the plunger/spring are moving freely.

I did change the oil filter also with it as I thought it may have been that possibly. Whats the oil filter adapter?? What am I looking for here? I did see something in the oil filter spot when I took the filter off that I pushed on with a screw driver and it pushed forward with a spring in it. It seemed to be working properly as it sprung in and back when I let it go. That what your speaking of? Whats the purpose of it?

Thanks
Conrad

https://www.gmforum.com/showthread.p...t=oil+pressure

This one outlines the adapter adn the spring/plunger.

oh ok. Now what is the purpose of it? What does it do. I know it must open/close something and what not. But would it cause the valves to knock like it is? I know oil cant be getting all the way up to the top of the motor...

That'* teh oil pressure relief valve/plunger. It let'* oil past to bleed off pressure above the spring pressure. If it'* not moving aka stuck, it could be bleeding all pressure off and not cycling it through the motor.

What does the oil pressure gauge say? If it'* showing pressure and then dropping off as the engine gets hot you may have a bearing going out. Could be a cam bearing if oil isn't getting to the lifters.

Ask him how he knows lol

oh ok. If its stuck that would make sense I guess that it would shoot it all back in.

Thank you

Conrad

Dan... I forget how many cam bearings we have...not sure if one cam bearing can starve the entire top end. Did you look at flow diagrams etc when your problem happened? Can one kill oil to all the lifters?