Oil Pressure Fluctuating

[amuddyzj]

I drive a 96 Grand Cherokee and my oil pressure has been falling at times then it jumps back up to normal. When I see it fall, it's when the rpm's are low so going on the highway or just waiting at a stoplight. I'm thinking that its the pressure switch but any other ideas? Thanks

 

[dandoc]

What have you done to search for the problem? How long has this problem been going on? Have you changed the oil and filter recently? Is the oil level low? Any new leaks that you've noticed? Feed us some more information so we can better help you.

 

[amuddyzj]

ok... I haven't done much looking to see what the problem is. It has been going on since mid-late august. had the oil changed in august (not sure before or after problem arose) Oil level is fine, it leaked at first but in needed a better washer so that problem was fixed. I know last late spring, when someone did an oil change they over torqued the bolt so we had to take the whole pan off and cut out the messed up thread and make a new one but it seemed to work fine then. My shop teacher thinks its the pressure switch and to test you use an oil pressure guage right? or is it worth getting a $30 replacement. andwhat is the difference between an oil pressure switch with light and with guage?

 

[jay79cj7]

andwhat is the difference between an oil pressure switch with light and with guage?

Switches that go with lights are on/off... Yes there is a minimum pressure or no there is not. That cycles the mated light, thus the term "switch." Switches that go with a guage aren't really switches. They have a variable output that gives the gauge its reading.

My sender went bad on my XJ last winter. The gauge pressure would drop to 0 for a while and then come back up to normal.

 

[amuddyzj]

aight guys thanks a bunch I'll let you guys know when I try to diagnose it and fix it

 

[Dry suit diver]

have you got the right viscosity oil in it?


the muppet dealer i bought my 96 XJ from put oil that was too thin in and getting the pressure gauge to read above half was a problem, changed the oil and filter put correct grade and a viscosity additive in and it keeps in the upper half of the gauge even at low rpm.

sorted the lifter tapping too.

testing a sender isn't easy as you need to know what it should be calibrated at. switch is easy its on or off !!!

for 30 bucks I would change it anyway, not the technician way but if it solves the problem.

 

[amuddyzj]

Pretty sure I'm using the right stuff, It's the same oil I've used before and had no problem with but I'll look in to it thanks