Oil Pressure & Overfilling?


New Member
Mar 20, 2023
I just bought a 1988 yj 4.2 6I and gave it a fresh oil change, it said it was right on the "add line" before the change, I pulled the plug and the filter and let it all drain, for 20-30 minutes. Only got around 4.5 quarts out. Which seemed odd.

New filter, added 5 quarts first and it measured fine and dandy on the dipstick. Ran it, and the oil pressure
was way past halfway?! And after the dipstick seemed to suggest it has an extra quart in it! So I let it sit a day and the dipstick reads normal but as soon as I run it the pressure goes all the way up and the dipstick shows extremely high again. Isn't the capacity supposed to be 6 quarts? Do I drain it and refill with less? Does I have a bad air bubble I need to get out? The old oil was pretty filthy, but I ran it beforehand and let it drain for quite a while.

Stoopid Jeep

YJ Enthusiast
Dec 25, 2021
North Idaho
Capacity is 6 quarts (according to Google)
Your oil pressure going all the way up with new cold oil is very much normal. Nothing to worry about.
Engine running can push the oil up the dipstick.
Wipe the stick and recheck after about 30 seconds. Should read normal.
Again. Nothing to worry about.
Take it for a drive, get it warmed up and check the oil again.
..Full send
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