I have a 2001 Buick Park Avenue Ultra. When I change oil and add the recommended amount, the dipstick shows almost 1/2 quart low. I had a 2000 Buick Park Avenue Ultra that also showed a low oil level. On my 1996 Oldsmobile and 2006 Buick LaCrosse, both with the same V6 3800 engine, the oil level reads accurately. What gives with the Park Avenue?
There are usually two numbers for oil change…One for if you change the filter and one when you don’t change the filter (although for the life of me I don’t know why anyone would change the oil without changing the filter). Are you sure you’re using the correct number. On my 4runner it’s 5qts WITHOUT changing the filter…and 5.5qrts WITH a new filter. So if I changed my oil with filter and used the first number I’d be 1/2 quart low.
If that’s not the answer then for some reason the dip-stick isn’t going deep enough…and I wouldn’t worry about it.
It might be your dipstick. I once bought a used car on which the handle of the dipstick was gone. I obtained a replacement dipstick, same engine, and was surprised to find there was a difference of almost in half inch (13 mm) in their markings. Go figure.