1994 Oldsmobile Cutlass Supreme V6 3.1L

I let Wal Mart change my oil. They put 10w/30 in my car and the cap states to use 5w/30. Six to eight hours after they oil change it stated to make a very loud knocking noise. It seem the noise is coming from the front lower portion of the engine. The car ran excelent before this. I mainatined it well and kept up with the oil changes, etc. 60k miles. Could using the wrong oil have damaged it? I live in Yuma, AZ. The weather here is anywhere between 58 to 70 degrees.


While I can’t explain the knocking noise, using 10W30 oil won’t cause any damage.

GM recommends most engines use 5W30 but in summer you can use the heavier 10W30.

I have 2 GMs and change them back and forth in the fall and spring.

I can’t blame Wal-Mart. You can if you want to. Changing the oil at 60,000 miles isn’t a good idea, oh, that’s not what you meant. See if you have ANY oil in the engine. The oil filter might be loose or they put a quart in there just to be safe.

I suspect it is not related, but it is possible. It is not due to the oil weight difference however what they gave you should be fine. Overfilling the oil is a possibility. Have you checked the oil level? Has the oil or CEL light come on?