For reference with the head the mechanic also replaced (just copying from the bill) head bolts, valve cover gaskets, camshaft, lifters, thermostat, timing chains, gears, timing gasket, cooling fan motor, and hoses. I was under the impression that he addressed anything having to do with the head issue which is actually why I bought this particular jeep. This was all within the last 5,000-6,000 miles.

I asked the mechanic that just had the pan off to switch the gasket and oil pump and he said everything was clean, no issues (but he knew about the sound and said there was nothing he could check). My problem is my limited understanding of how all this works so I never know who to believe (which is why I come here, you guys know your stuff and I value and appreciate all opinions).

 

What I got from Autozone (which looks identical to what is on there, see second pic) looks different that what I find online (first pic).

Am I replacing the wrong thing? Its just above the oil filter. Do I have the wrong part on there now?

 

I forgot you had the head replaced. It's likely that the old cracked head allowed antifreeze to enter the oil and do a number on the bearings over time. This is what happened on mine. It's either that or you have flywheel bolts loose. Either way, that is not a normal sound IMO. Valve train noise is more of a 'tick'. You can look at bearings and see if they are all gouged up so there are signs to look for that they're damaged.

 

Sounds just like this guy:


Would flywheel bolt noise go away when warmed up?

 

Anythings possible.... It's easier to check and tighten them then to check the bearings... so do the flywheel bolts first. It's a common issue.

 

Is that a DIY job that I can do in my driveway?

This right - https://www.cherokeeforum.com/f51/ho...ocking-125547/

 

Yes, easy job. Hopefully that's your issue.

 

I would feel a lot better if I could get oil pressure right, did you see the pics I posted, is it possible I got the wrong part?

 

Well I run 5w/30 Mobil 1 in mine and even at idle it's much higher, that's why I asked.

 

ROD BEARING KNOCK: Makes sharp metallic noise similar to a piston slap. Detection is opposite of piston slap. Rod knock is not heard at idle. Knock becomes louder as engine speed is increased.



PISTON SLAP: Makes a sharp metallic noise. Noise will also disappear as acceleration increases.

 

I think your original oil pressure sending unit was probably correct. I just don't trust anything from Autozone except wax and oil dry. The AZ part doesn't look like the MOPAR part. If you would really feel better replacing the sending unit, get the MOPAR one. I wouldn't like being scared by 0 oil pressure and warning lights.

In addition, your original oil pressure seems to be right where it should be, based on the miles and condition of the engine.

As far as the poster saying you can change your bearings in the driveway, well I guess you could. I see people trying to pull engines and transmissions at the Pick-A-Part yards with a Crescent wrench and a screwdriver. I wouldn't want to do that.

But what about the main bearings and cam bearings? What about having the crank miced and turned?

This is the third time I've said this, and I won't say it again. Promise. Either pull it out and rebuild the short block all the way, or leave it alone.

 

Luckily we have mechanics at my job, I borrowed a mechanical gauge and it reads higher than the dash, attached pic is hot idle. Makes me feel a little better anyway. Order a genuine Mopar sending unit is the next step I guess.

Firestorm, I am with you and I appreciate the advice. If I am going to spend money it will be on a rebuilt engine (hopefully in another 100,000 miles).

 

Pressure is fine. While you are losing sleep worrying over this your engine is happily chugging along. When she (engine) has had enough she will let you know and you can make your decisions then. FYI I thought my 4.0 was on its last legs ( 4psi pressure) 4 years ago. I bought a replacement engine for when that time comes but she runs sweet and won't quit! I see no useful purpose in replacing it until thing get worse.

 

That's much better. It is amazing what these engines will tolerate and keep on chugging away.

 

No, I agree with you.. it would be an incomplete bandaid. It was just a thought if he had the tools and time, it could be something he could look to track down the noise.

And x2 on that sender. Take it back to AZ and run your OE one. The dash gauges are not always very accurate.

I'm still curious to see if its the flywheel bolts or not.