Long Time Since last post, sad reason to post now

[GreenMachine]

Here's a "video" of the "sound", I tried to move the camera around to get full sound:

http://smg.photobucket.com/albums/v348/Big...¤t=richscar.flv

The car has been in a incident involving the oil pan being replaced (hit something to damage it) but that was long before this issue appeared

Vehicle has had knock sensor "replaced" or possibly tampered with for the check engine light relating to knock to be fixed. I say tampered because it may still be knocking but the car isn't sending the light, or it was indeed damaged and the car knocked itself to near death.

Car looks flawless btw. Beautiful white and interior is great, I like the center console, has (what I assume) is a performance shift button on the shifter. To bad Old's is no longer with us, why the couldn't do with that what saturn is turning into I don't know. If need be they want to replace the engine in it to keep it going, and by the looks of it I don't blame them.

4.0 Northstars hard to find I bet? 4.6L swap possible? But before that maybe the current engine can be saved. Apparantly no shop wants to touch it now and a local chevy dealer replaced the torque converter, from the story I can't tell if that was to fix the rough running issue or not.

The reason I'm thinking Lifter problems or Rod knock is because of the low oil pressure warning that has popped up recently. I didn't want to push it to redline or anything but the highest pressure I saw was 18-20 I believe. What's the normal range?

Hope you guys can help him out, then intern I'll help him out too

[BodybyFisher]

Hmm, lots of info in your post, I am not sure where to start. First thing you need to do is to find out what is going on with the oil pressure, 18 it way too low, and my guess is that it should be at 30 psi above idle. I assume the car has a gage? You need to determine if its accurate, but I would start by replacing the sender, in this case (not switch) as you need to see if you have NORMAL pressure. IF a new sender does not fix the problem, I would immediately hook up an oil pressure gage, and see what it actually is. Obviously with the KNOCK, I get a bad feeling in the pit of my stomach due to the potential of low oil pressure.

Given that the oil pan was replaced, its possible that the oil pump was damaged by ingesting pan material that scored the vanes/gears, the pick up was damaged or dislodged, the pump is bad.. The pump may have appeared to be good at the time the pan was replaced but was damaged over time by ingested material. Does it have a case half leak? I don't like the sound of this one. How long has your friend been driving with low oil pressure? Is the DIC notifying him with alarms or messages of low oil pressure?, or are you basing this solely on the gage? Is gage digital or analog?

It is not likely that you could put a 4.6 in, all of the electronics would need to move over too, plus what tranny is it?, not likely the same tranny, if you kept it it would mess up the NEW engine PCM. Plus you couldn't keep it because it might not bolt up to 4.6. Forget about using a 4.6, the potential problems are numerous., not to mention that there could be a physical size issue.

[GreenMachine]

He has gotten a low oil pressure warning on one ocasion. I was using the gauge the DIC has for oil pressure, I guess the Old's got em but the caddy's didn't

He has said nothing about losing oil or oil spots.

He first called this to my attentiong a month or so ago, but it was writtin off as a misfire problem and they went threw that ordeal of working on the usual culprits of that. I think its been driven sometime in this state.

Intresting you said oil pump, because it almost sounds like a compression sound along with the knock.

They oil is changed by a shop from what I gather but I was thinking to change it and send it out to one of the oil analysis labs or see if I see "anything" in the oil.

Thanks for the reply,

Ed

[Cadillac Jim]

Your link to Photobucket doesn't work; it as abbreviated by an ellipsis in the middle and that's what got into the Caddyinfo link.

Lots of mechanics still believe that if a computer-based car has a warning, it's the sensor and they attack the computer, not the problem. That's probably what happened to your knock sensor. It it looks damaged, I would just replace it. It comes as a set with the snap-in knock sensor module in the PCM.

If you really, really want a 4.6 in your Olds, I think that you may be able to do that, but all the sensor wires would have to hook up. If the Olds has an oil pressure transducer and the 4.6 has an oil pressure switch, you would have to figure out how to move the oil pressure transducer over to the 4.6. The knock sensor module from the PCM of the 4.6 would have to snap into the PCM of the Olds and work. I would keep looking for someone who had done this and see what they say.

[GreenMachine]

Opps,

video is fixed:

http://smg.photobucket.com/albums/v348/Big...nt=richscar.flv

Thanks for telling me

Ed

[BodybyFisher]

I just listened to that video and I really don't hear anything serious, sounds like the muffler is leaking, but nothing that gives me a bad feeling. Sounds a little rough maybe needing wires and plugs

[Cadillac Jim]

Sounds like lifters to me. If it goes away when the car warms up, I would ignore it. The oil pressure should be checked if you are getting low readings at 1500 rpm and higher, though. Anything over 5 psi is good enough for idle.

[newbold1]

You could just leave it that way and tell everyone that you've got a Cummins diesel engine in that car. ... just kidding.

[Texas Jim]

I don't have a manual for that car.. but I would guess that 25 to 40 would be normal oil pressure at highway speeds.

As for the sounds... the only thing I couds hear... sounded like lifters and maybe an exhaust leak.

I think I would hook up a mechanical gage and see what the pressure REALLY is. If the pressure IS low, that could cause lifter noise. The hydraulic lifters are run by oil pressure.

[GreenMachine]

The sound I am hearing is actually most hearable at about the 38-34 mark (right at 35 to be precise, that video counts down not up btw), its like a loud thumping that is masked by what I assume is the injectors.

I'll do some trouble shooting on it to see what I come up with. I'll check to see what kind of plugs/wires are on it. They say a lot of problems seem to have creeped up around the time they had a tune-up.

I just assumed something is wrong because I compared the sound to that of my 3800, Northstar, and picked out the sounds I don't reconize, such as the that knocking sound. Pretty much all the noises it makes are nearly the same as the Caddy's northstar, just ALOT louder.

[Cadillac Jim]

Maybe it's my headphones but I couldn't hear a thumping, but I could hear several valve lifters, one a lot worse than the others. This might be normal for that particular engine when it is cold. If the oil pressure is normal, and the lifter noise goes away when the engine is fully warmed up, an oil and filter change and a road trip might be a good thing for this car.