1998 Jeep Wrangler 4cyl Low Engine Pressure



I have a 1998 Jeep Wrangler 4cyl, just getting broken in with 190,000 miles. Recently, I have been getting low oil pressure when I idle. It only gets low oil pressure when I drive it for more than 30 miles. I use 10W-30 Mobile 1 Synthetic and very religious about changing the oil every 3,000 miles.

Here’s the thing. When I am at speed (RPM’s over 1,000), the oil pressure is fine. It is only when the RPM’s drop to idle at 700 that the oil pressure will drop below 10psi.

I immediately checked the oil for gas/water since I figured that would cause it to loose pressure as well, but nothing.

I even took it to the shop and they said they saw wrong with it. They ran diagnostics and checked the oil as I did and blamed the problem on the mileage. Yet, ever now and then if the pressure drops below 8psi, the check engine light will come on and I really don’t want to be driving it even though “there’s nothing wrong with it”. I thought about changing the oil pump or using a heavier weight of oil.

Any suggestions?

Many thanks.


Heavier oil may mask the problem for a while.

It may be the oil pump, but I fear it is going to turn out to be engine wear.


Wouldn’t the pressure have gradually went down over time if it were wear on the engine? This just started happening about three months ago and noticed when the check engine light came on. I have not heard any knocking and no change in performance of the Jeep. It still runs smooth. If it were the bearings, is this something I can replace/fix?