I have a 1996 Cherokee 2 door with 5 speed manual and the inline 4.0 L 6 cyl engine. I got an oil change on Saturday and noticed that the oil pressure seemed to be a little higher than it was before the service (according to dash gauge). I checked the dipstick and the level seems pretty high. I called the garage and was told they put in 6 quarts (which is the specified amount). In the picture below, the bottom of the dipstick is toward the top (off view). The key is pointing to the upper line of the "SAFE" range. The black mark (between the "T in "NOT" and the "O" in "OVERFILL" indicates the level of the oil. Does this seem right? I know having too much oil is not a good thing. Thanks in advance for your help.

 

6 quarts is what the manual calls for. I normally put in 5.

I would not trust a shop that blindly dumps in the stated amount and calls it good.

 

I know some times shops use overhead oil guns and the gauge on the overhead guns are not that accurate . The oil pressure on my xj is always higher with new oil . more oil in the engine does not mean more oil pressure .

 

I usually shoot for the "E" in SAFE when setting my oil level.

If it is higher than that upper mark, I would pull the drain plug and drain some out. Will only take 5 minutes or so - worth the peace of mind.

 

I'd make sure they changed the filter. Because this is what happens when you add 6qts without a new filter. But at this point, it doesn't really matter why its high. Just drain a little out until you are back in the safe zone.

 

Thanks for the replies. They did indeed change the filter. I am going to drain some of the oil. It's just odd that if the specifications call for 6 quarts, why does there appear to be too much on the dipstick when you put that much in.

What IS the danger of having too much oil? I thought it was because the pressure would be higher and oil would get by oil seals.

 

Too much oil and it will aerate. The oil acts like sandpaper.

 

It doesn't on mine. 6 quarts plus filter change puts it right on the mark.


Aerated oil (by the crank whipping through it) is no good.

 

One of following occurred:


1. More than 6qts was put in
2. Oil was not completely drained
3. Some mixture of 1 and 2


I buy 6 qts for every change. With a fresh filter this amount is near perfect.

 

Thanks for the additional information. Especially about what happens with too much oil. Is it possible the dipstick is not the correct one for the engine? That maybe a previous owner misplaced it and got another one that isn't for that engine? I kind of doubt it myself, but that is another possible explanation.

I'm going to assume for now it's the right dipstick and drain some of the oil so that it is within the correct range.

Thanks again!

 

IIRC, the dipstick did not change from 1987 to 2001 for the XJ.

One way to know for sure is to change the oil yourself next time, and see how much oil it takes. Should be 5.5qts or so with a filter change.

 

Another negative to too high of an oil level is that it can negatively affect your fuel mileage.