Oil Pressure

[rtitteri]

'96 Cherokee Sport. Straight 6 4.0 4WD 115,000

I am having an issue with my oil pressure. When I first start the Jeep the pressure reads normal. As I drive for a few moments, and hit any stop/go traffic, the gauge needle "jitters" and begins to lose pressure. After a few miles and a few more stop lights the oil pressure drops below normal levels.

I checked the dipstick, and the oil level is just below the "safe" mark, and there is a minor oil mark on the pavement where I park.

Any thoughts?

[wrightz28]

There's many threads on this.

Seems that it is common that upon start up the gauge will read 40-60 psi, then once the oil warms up, the pressure reading will ease down to 10-20 psi. Rule of thumb is so long as you have 10psi per 1000 rpms, you're fine.

I will say from a recent experience, if you're getting less than this, make sure your oil filter adapter gasket is not leaking. This will cause (not only a mess) but a very low oil reading not only at idle but while driving at higher rpms as the pressure sensor is right there. When my gasket was leaking, 10psi was the norm. Now that it's all sealed up, I'm running 15-20 at idle and up to 40+psi when on on it, which runs in accordance with the rule of thumb

[rtitteri]

Took a drive this evening to attempt to diagnose. Here's the result, hope it helps.

Upon start the oil pressure gauge hesitates for a second, then reads about 40psi. Once running, the gauge flickers or bounces, and begins to drop. After a few minutes of driving between 20-40psi the gauge continues to flicker and drop, and drop significantly at idle (such as at a stop light). After several minutes of driving or stop/go traffic the gauge drops to 10-20 psi while on the throttle, and reads 0 at idle. If at idle and you tap the throttle, the gauge will jump and read 10-20 psi, then return to 0.

Dip stick reading is just below "safe" level, running 10W30, and there are just a few drops of oil on the pavement where I park.

Any thoughts?!

-Cheers

[Boost1egt]

You can try this. Install a pressure gauge (where you can, usually in the hole where the oil pressure sensor is installed) and start the engines. Notice the oil pressure at different engine speeds. If its ok, and the oil pressure sensor connector and circuit looks fine, then most likely the oil pressure sensor its in bad shape.

[wrightz28]

Originally Posted by Boost1egt

You can try this. Install a pressure gauge (where you can, usually in the hole where the oil pressure sensor is installed) and start the engines. Notice the oil pressure at different engine speeds. If its ok, and the oil pressure sensor connector and circuit looks fine, then most likely the oil pressure sensor its in bad shape.

Agreed as replied in PM.

[Scrapper]

i spray brake clean on where you see oil or even oven cleaner works and then keep checking where oil leak you think is coming from see if oil sensor/oil sending unit is. but i bet there wright on the sensor/oil sending unit.

[rtitteri]

With limited resources, I gave in and left my Jeep in the hands of a local mechanic this morning... now the waiting game.

Wish me luck... I'm going for at least another 100K!

[fredjacksonsan]

Luck...post back if and when he finds something. New oil pump?

[wrightz28]

I don't think it's anything that 'serious'. Definately post back what he finds.