I have a 2001 Cherokee with the 4.0 and I have been running low oil pressure. It started when I towed my Comanche on a trailer and when sitting at a stop light the check gauges came on and the gauge read zero! I hooked up a manual gauge and when warm it reads between 12 pounds and 0 pounds of oil pressure. My question is: Is it possible that when towing for 15 miles with a heavy toung load that I starved the front main bearing causing this low oil pressure? When started I have 60 psi and it dropps to around 8 pounds when warm on the sunpro gauge.

I don't want to pull the pan and get into it if it's something else, but I do not want to damage the engine either.

Thanks!

 

is this a high mileage vehicle?
there are three causes.......oil pump, oil pump screen clogged, or main crank bearing failed(excessive clearence will cause pressure drop , but not any noise)

 

It has 103k on it, and my '98 cherokee had 160k on it and had at least 15psi of oil pressure at idle. It doesn't make any noise so I am leaning toward the main bearing, but I don't know if it's bad that it would have 60psi at startup if it's bad? The kicker is the oil pan gasket is newer so I don't know the history of the engine either which bothers me to no end.

Thanks for the reply!

 

I have the same issue...

 

I have the same issue and i have replaced the oil pump and screen.

 

you will prolly have to tear into it. at cold start up mine has 40 psi, and when the oil warms up it only has about 15-20 at idle. i have seen pumps online for less than $90. i am going to have bearings, seals and a pump in hand this winter and just do it all at once just to be safe. good luck man.