2001 Jeep Cherokee 4.0 oil over fill problems?
A friend carried her Jeep to a garage for an oil change and it has not been running right since.Her bill lists 5 quarts of 5w40 and 1 quart of 10w40 (6 Quarts total). Will over filling create problems? Thanks!

Engine with filter, 6 qts..
http://www.jeep4x4center.com/knowledge-base/jeep-wrangler-fluid-capacities.htm

I'd guess maybe the PCV valve was jarred lose, causing a vacuum leak? Maybe at the brake canister?

She says that the oil level is way up on the oil stick.Will too much oil affect the way the engine runs?

WAAAY up it certainly would, but a just a quart over, no.

Why one odd quart?


And, hopefully it didn't end up 5 and 5 (quarts).

Since oil control has gotten so much better I don't do it, but back in the "good old days" when going on a trip I routinely added an extra quart before I left.

And with some of those beauties ... I remember a trip from Florida to Vermont... it took 35 quarts for a 1400 mile trip ... '70 Monte Carlo SS454.

I run my inline 6 cylinder a quart over all the time, helps keep oil pressure when the jeep is on a steep hill...think rock crawling. Tim

Mine has always been fine with the stock oil level, unless leaning way way over on the passenger side.

But like mentioned above the 4.0 holds 6 quarts of oil.

You are all assuming the place that added 5 quarts of one grade of oil and 1 quart of a different grade actually drained out the old oil before adding the new "mix".

I'm pretty sure if there are 12 quarts of oil in the 4.0, its not going to run very well. Gene