98 cherokee, 4.0, around 130,000 miles

Okay, so i am currently running castrol high mileage 10w30 oil, but it did this before i started using this oil. No change, i just always used this oil in all of my vehicles.

Once the truck has been running for a good while and it is at its full running temperature, the oil pressure drops low at idle. It usually will hang on to the last line before 0, so i'm guestimating that this is 10psi. sometimes it looks like 9, but it could be just the angle im looking at the gauge. It NEVER goes below this point. Although, once i accelerate, it rises again, back up to 40/50, whatever is normal. Also, when it is at this low psi, i can hear like a pup pup pup pup (sorry, i dont know how to describe it better) inside the cabin coming from the engine. My chrysler sebring used to make the same pup pup pup noise.

i am definitely concerned, but everyone is telling me that its SUPER common for jeeps to run this psi at hot idle and that the noise that im hearing is normal as well.

additional info: doesnt burn any oil, doesnt use any coolant, coolant is super clean and green, and oil looks absolutely fine.

Any ideas?

 

Cherokee 98 4.0 130000 miles

General question, and not even sure if i need this done, just curious..

When replacing cam bearings, how much work is involved, and how much does it usually cost (round about, i know prices are different for parts, dyi, or mechanic)

 

Check it with a mechanical gauge if you are worried. The spec for the 4.0 engine is no lower than 13 PSI at hot idle. First make sure what your gauge is telling you is correct though.

 

Here's ^^ your answer. VERIFY the oil pressure.

Just curious, what brand of oil filter are you currently using?

 

Pretty much complete engine teardown after removal from vehicle.

Howzabout keepin all your oil pressure questions in the original thread you started instead of starting a new thread each time an idea pops into your head?

I merged the threads.

 

Usually you replace your cam bearings when you do a complete engine overhaul. When they dip your engine to clean the block before the rebuild the chemical that it is dipped in will remove the cam bearings. It would be best to do it when you do an engine rebuild.

 

Purolator PureONE. But it was no different before i used that one

 

Thanks for that. I'm still getting used to this forum type thing. I'm used to just posting questions in yahoo answers. Thanks for the tip

 

Is that the banhammer sneaking up behind you?

 

Indeed verify with a mechanical gauge. That said, low oil pressure and noise appearing at the same time is generally A Bad Thing