I sort of have the same problem with the oil pressure gauge as being discussed here: http://www.bonnevilleclub.com/forum/...3a21e7f6ef0c78

I have a 1996 SLE with 218,054 on it, the pressure drops in the red after a fifteen mile trip on the freeway, then when exiting, the car starts to make a ticking or rattling sound. It'* sort of hard to diagnose it from inside the car. I use Castrol high mileage 10W30 which help pretty good I think. I was scared that the car might die because when the pressure got low, the chime was blaring when the needle got to the red level. I then put the car in neutral so it wouldn't have the chance to stall, and gave it some throttle to see whether the pressure would go up. It did go up, but I was not comfortable driving it, so I immediately took it to my trusted mechanic who said the engine was going bad and needed replacement. I did not want to put anymore money into the car with those kind of miles. Then I heard that it might be something relatively minor, oil pump, sending unit, or bearings. I'm trying to sell the car and just totally clueless to tell the people what is really wrong with it. I want to be honest with anyone I deal with. Any clues what it might be?

The sending unit would be the minor fix, but it doesn't sound like a bad sending unit. As BillBoost mentioned in that post you have linked there, the bearings play a part in oil pressure. If you're willing to drop the oil pan and inspect the rod bearings there, then I'd say you're set to fix this issue.

The first thing to do, though, would be to check your oil filter adapter, as was also mentioned in that post. Then go to dropping the oil pan.

A drop in pressure, especially after warmup is almost NEVER a pressure sensor. It'* typically a critical problem with the motor.

Have you ever had an UIM failure? Maybe you should update your For Sale topic with this warning? This is possibly a very bad thing for you.

I agree, you cannot ethically sell this car without disclosing that your engine is worn to needing a serious overhaul or replacement.

I did say that the mechanic recomended a replacement engine, however, they also wanted to install a 70,000 mile engine & tranny for $4500.00. So that'* why I don't want to put in anymore money into it. The body is still in great shape.

Check my post for the pitfalls of ignoring your bearings:

http://www.bonnevilleclub.com/forum/...ic.php?t=74692

If I'd of paid attention to what the motor was telling me, I could have saved it months ago.

The good news is you can probably get it fixed for much less than $4500.

Good luck,
Matt

In my opinion your mechanic is a crook and you should seek a reputable shop.

Your engine is probably tired and worn out. The bearings do wear and have worn to a critical point in your case. That motor the mechanic is trying to put in would cost him no more than $800-$1000 (at the ridiculously high most) and any labor over 10 hours is an overstatement if they've ever worked on a GM car.

To put new bearings in would also be a waste of money. At this point the engine should be rebuild or replaced. Bearings may buy some time, but it won't be long and the rods/crank would need to be checked/possibly machined etc at even more cost.

Well, I have been unsucessful in selling the car. The car is in great shape in and out, but the engine problems have taken its toll. It does make the clattering noise when up to temperature (200 degrees). It doesn't make any noise at idle or heavy acceleration when the engine is cold. I want to take it to the local CarMax and sell it there. Should I change my 10W30 oil and put in 20W50? When it does make the noise at normal operating temps, will the heavier oil make a difference in clattering noise reduction? I just want to get rid of the car.

IMO, that car is just begging for a second life with a L67/4T65E-HD swap.

With a worn out engine, no type of oil is going to fix it. Sell it as is if you like, but you should be honest about the state of the engine. Realize that selling it for what it is -a car that needs an engine- will lower its value. But it might be the right car for someone who is willing to put an engine in it.