1996 Buick Lesabre may have been damaged by overfilling of oil. How many liters should be put in it during an average oil change? How many liters is too much oil and should definitely cause damage?

I had a local oil change lube place change my oil and now I am having problems with it and it is undrivable. The oil pressure went to zero but there was not a dripping puddle or anything. Terrible rattling sound under the hood somewhere.

The independent mechanic not associated with the lube place that I had the car towed to initially was familiar with the car, called the 3800 a great engine and said that 155,000 miles is not much for these cars. He said it looks like it was way overfilled. The lube place looked at it and said that it was not overfilled and that it had maybe 0.5 liter to 0.75 liters too much but that would not cause a problem and is in a normal range.

The lube place's records say they put in 4.5 liters but, now they are saying it looks like maybe 5.0 to 5.25 at most and this was normal and the car is on a hill and all this stuff. I'm gonna have the independent mechanic drain it and measure the amount of oil with all parties present. He is willing to do that.

He told me how much he thought it looked like it was overfilled but I don't want to say it because I don't want it to affect what people say. Independent poll kinda thing.

How many liters of oil would be too many and would most likely cause damage? Thanks very much for your help.

 

I have two buick 3800s and they take 5quarts (4.7L) with a filter.

To find out how much oil it would take to damage it you'd likely need to contact the GM engineering department.

The problem is when you get too much oil the crankshaft starts to whip the oil into a foamy mess and the oil pump starts pumping (trying to) the foamy mess with a lot of air bubbles in it. The air doesn't support the rotating assembly and the bearings start to get scored and eventually fail. The cam bearings, connecting rod and mains would take the worst of it.