Cane

Hey so I recently did my first oil change on my jeep, usually had it done for peace of mind but decided to do this one. I don't know if I made a mistake or if it's unrelated.

Here's my situation. First time driving 45+ mins after the oil change, everything was fine and I didn't notice any problem. Now about a week later, the two times I used the jeep this happened within the same time frame. At first the oil gauge reads OK and the jeep feels normal, but after 10-15 minutes of driving (a long time after it reached operating temp) idle RPM in drive rise to about 1,000 RPM (usually around 700-750) and when shifting in neutral, the RPMs rise to about 1,500. Oil pressure gauge is still normal at that point. About 5 minutes later though, the gauge pegs pas the max, going way beyond the scale, pointing at about 4 o'clock if it were a clock.

When letting it sit and starting it again, oil pressure reads fine which tells me it's not a faulty gauge.. but again I don't know if it can be intermitent or not? Also the fact that it goes beyond the scale is weird to me, wouldnt it stay within the scale if it were an oil pressure problem?

Both times I was close enough to my place so I just stopped driving to avoid potential damage, but I'm wondering if those two are related? When looking at the dipstick I have about a half inch over the max line. I emptied 5L plus the filter, and put back in a 5L jug + a quart.

Thanks for your input!

cruiser54

Common to smack the oil pressure sending unit when removing the filter.

Cane

is the sending unit only for the gauge or also sends info to the computer? my next step was to buy a new one, but was not sure between MOPAR 56031003AB and MOPAR 56026779AB for my 96. there's a 30$ difference between both. one lists for 92-96 and the other 96-97.

cruiser54

I'm not sure on that new fangled stuff.......

Cane

alright cheers! i'll try a new sending unit, see if it at least fix the gauge. maybe the rpm problem is unrelated.

jpz

I recently replaced my sending unit for a similar issue that you're explaining about the gauge, (I did not have the idle issue that you mentioned).

dave1123

You can try cleaning your Idle Air Control. It's probably dirty and sticking once in a while. Mine likes to stick when it's damp outside. It's in bad need of cleaning.

PatHenry

Sending unit definitely doesn't have anything to do with driveability, even if it's a later year 96 (closer to 97+) or early year 96 (similar to 94 and 95).

You can check the date of manufacture on the door sticker to see when your 96 was made. If it's later on (in calendar year 96) it's more likely to be the 96+ sender. If it's early on (late 95 calendar year) it's likely the 94-96 style. Really though, check out the part on some of the major auto parts retailers (autozone, o'reillys, napa) and they should have information about determining which part is specific to your 96. It may be by checking the date of manufacture or VIN number or something like that.

I would follow dave's advice and try cleaning the IAC and doing the general maintenance items like checking/cleaning grounds, etc.

Cane

yeah will definitely give it a good clean up and go for a drive see if it helped.

i remember the TPS and coolant temps sensor were both wrong when I ordered for a 96, had to get 97 ones. I think I have my answer as far as the part goes.

thanks!