Well my 1990 Xj is acting up,whenever I drive it over 20-25 minutes my oil pressure drops to 10-20 psi at stoplights.

When this happens my trans slips while driving along at a steady pace then the motor revs like Its in neutral like a torque converter going bad

My oil pressure is at 40-50 at idle regularly before it starts acting up.

I've replaced the tps and replaced two quarts of auto trans fluid so far.

Anyone know what the problem is?Or things I could try to get a definitive answer about exactly whats wrong with my Xj


Please help me cf!

 

Engine oil pressure seems normal.

Two qts trans fluid is a lot. Got any leaks?

 

No leaks,but the old trans fluid was really burnt and dark.

It took the new fluid well,and shifted better after the change,but still acted up after driving for some time.

Its been about 50 miles since the fluid swap so I'm about to swap another quart of new fluid when I get a chance to work on the jeep.

 

Drain and refill again.

 

As stated, your engine oil pressures are OK.

I'm confused how you can only replace 1 or 2 QTS of trans fluid ??? If you drop the pan it is about 5 QTS.

Like Cruiser sez. Drain and refill. Might have to do it 2 or 3 times to get it running nice and red.

 

Its just abnormal for my oil pressure to be that low,used to be 40psi constant

I got two quarts from pumping it out of the trans cooler lines,but Ill drain and refill some more today

 

The minimum spec for oil pressure on a 4.0 is 13 PSI. 10 is definitely not normal. A sudden drop like that is usually indicative of your sending unit go out - a common failure. You should verify with a mechanical gauge but it's likely just the sensor. A failure in your oil filter is also a possibility. If you have an orange FRAM on there or a rebranded cheap unit (quick lube type places, or store brand in the same price range) you may want to rethink how much you value your Jeep and put a real filter on like a WIX/NAPA Gold or better.

Also the total system capacity with the AW4 is about 8 quarts. The tranny itself holds 4, the rest is in the torque converter and cooler. You need to change a lot of fluid to get all the burnt crap out.

 

Oil pressure should never be constant at different RPMs as teh pump is driven off the camshaft.

Drain and fill takes 3.8 quarts. Use the plug.