Oil fill level

[bayouboy]

i just did my first oil and filter change on the 88 avanti. i added 4 quarts of oil and a pint of STP and the reading was low. another quart and it's still not full. the dipstick/tube arrangement is strange. it's a winding curve that is not anchored at the top. the tube must be held and the stick forced an inch at a time at some point as the tube seems to wind in directions contrary to the "flat" of the dipstick. so... i'm pretty sure something is wrong, but not sure what. what's the dipstick tube supposed to look like and have others experienced this problem?

[Gunslinger]

It's possible your car has a wrong dipstick...a not uncommon thing with cars that have passed through more than one owner. It also makes me wonder what oil filter is installed on the engine...Chevrolet used two different length oil filters on small blocks depending on the application...a long and a short filter. They fit the same but one holds maybe a half quart more oil. The long filter is generally for trucks with lots of clearance area for the extra length. Cars generally use the short filter, but there's no reason a long filter can't be used if sufficient clearance is available. If your car has a long filter installed, that could be the source of your issue.

It's also not uncommon for engines with the correct dipstick to be inaccurate...they're just a guide and not truly calibrated. Your car could also have had the oil pan changed at some point to one with an extra capacity pan but that's probably the least likely reason.

What you can do is make sure which oil filter is installed, add five quarts of oil, let the engine run a minute to circulate then shit down and let the oil settle. Then take your dip stick and notch it where the accurate full spot is if the marks aren't already lined up.

[IndyJimW]

87-88 Chevrolet 5.0L engine - 6.0 quarts with filter change.