i have a 2001 cherokee sport. My oil pressure has been low at idle for the past month or so, only like 10psi while warm. Yesterday i noticed a pretty loud knocking noise coming from the top portion of my engine along with a ticking noise that kind of sounds like a diesel engine. This randomly started yesterday. It is only present when warm and goes away as i accelerate. My oil is clean and i can not see any coolant within the engine via dipstick or oil cap. No loss in power and sounds fine when im driving. Im not too knowledgable on engines but my jeep has the 4.0 inline six.

 

jeep has 170k

 

Can you take a video of the noise? There's a chance it could actually be low oil pressure causing it to knock, but the stock oil pressure gauge isn't always accurate. You could buy/borrow an mechanical oil pressure tester to see if it really is that low. What kind of oil are you running?

 

i am running 10W30

 

Sounds like you may be having some lifter issues. it may have even bent a pushtube. Not sure what your environment is like for temperatures, but I would think an engine with 170k might need a thicker oil than what you are currently using.

 

I live in new york. Temps have been in the 50s daily and 40s at night. What oil do you reccomend

 

any 30 weight oil (5w-30/10w-30) should be fine with those miles, unless you want to try 10w-40 or something and see what happens. Could also be a stuck lifter or bent pushrod like Bugout said.

I run 5w-30 Mobil and my oil pressure is around 40 psi even when hot, and that's at 202k miles. Really depends how the previous owners kept up on maintenance, otherwise the bearings can wear down and cause low oil pressure.

 

Sorry, I had to go run and take care of some business. Since winter is coming pretty soon I wouldn't try anything thicker than a 15-40 to see if it helps with your issues.


Your oil clearances are getting greater with 170k on it so this shouldn't hurt anything. But if it does not eliminate your noises then the rocker cover should probably come off to inspect the valve train.


And it has been hammered around here pretty well to not use Fram filter. lol

 

What kind of oil filter are you running?

 

I have a fram filter. I will change it as i change the oil. What brand do you reccomend? Also, these symptoms have showed up as cooler weather came. Should i try a lighter oil? Maybe the oil im using now is too thick with this change in temp.

 

Literally anything is better than fram. Fram filters have stupid high bypass pressures and a single use bypass. Once they bypass they are done. Most recommend is wix also sold as Napa gold. I run Baldwin filters myself.

 

I will bet that is the cause of your problem, not the oil. I put a fram on when I first got my jeep and it gave me oil pressure issues. No noise but the engine was not running right. Switch the filter out asap. I use NAPA Gold.

Fram oil filters are absolute junk and I know first hand, not just what the internet says.

 

I recommend you use mopar filter m090

 

The knocking is not constant or rythmic. It almost sounds like something is ocassionally hitting the side of the engine block right above the oil filter. In the cabin i also hear an odd sound like running water coming from the engine. These sounds are completely new so something had to happen within the last 3 days. My oil level is fine. Any other ideas? Should i try a lighter oil? The symptoms also seem to be worse in the morning and night when its colder outside.

 

I would strongly recommend taking the rocker cover off and making sure everything is correct and oiling right on the top end. It could have a loose rocker, bent push tube or broken valve spring. The location you describe is right where the lifters ride on the cam. A lifter could be bouncing on the cam lobe caused by other valvetrain issues. There could be cam bearing issues keeping it from properly oiling the lifters causing them to collapse a bit.