Oil Pressure ?
Herp Derp Jerp
Joined: Nov 2011
Posts: 18,251
Likes: 17
From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
Seasoned Member
Joined: Jan 2011
Posts: 437
Likes: 0
From: Central Jersey
Year: 91
Model: Cherokee
Engine: 4.0 I6 H.O.
Thanks for the info everyone. I went and got a new oil pressure sending unit from NAPA and put it in. I started it up and it's between 40 & 45. No leaks either. Mine didn't come with a gasket or sealant, it had what looked like red locktite on it already. Now, I'll probably change the oil and dump some Barsleak Engine Repair in it to treat all the seals. Life is good.
Thanks guys, no O-ring on mine, I put a very small dab of rtv near the end of the threads. Probably not doing much, other than piece of mind for me. Haha
Junior Member
Joined: Sep 2013
Posts: 99
Likes: 0
From: Oxford MI
Year: 2001
Model: Cherokee
Engine: 4.0
Just as a side note to those who havent changed there sending unit yet. DO NOT get lazy with the rachet like I did and snap the brass fitting in half. I now have to buy another sending unit for 50$ and I will have to use the torch to get the threads of the broken sending unit out of the 90degree fitting.
Thread Starter
Junior Member
Joined: Apr 2011
Posts: 55
Likes: 0
Model: Cherokee
I just figured that since these things leak at times like the titanic, some seal repair would be a good thing. My rear main was leaking about a year ago, I put some Bars Leak rear main seal leak stuff in the crank case and the problem was solved. It burps out of the top of the crankcase tho and spills down the side of the engine. I don't remember my TJ being this dirty.... I am getting old tho and my memory is not as good as it once was.....
I have been using Motorcraft 10w30 in it every 5k miles. This thing maybe gets 7-8k a year on it, MAYBE. I was thinking of going back to every 3k mile intervals. I don't want to waste product, but I changed the oil about 1800 miles ago and it's pretty damn dirty.
Herp Derp Jerp
Joined: Nov 2011
Posts: 18,251
Likes: 17
From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
Additives like that are very bad for the 4.0L and pretty much any engine. They reduce component lifetime drastically as they clog up all of the vital narrow passages in lubrication and cooling systems. They're only suitable for "I need to drive this for another week so I can buy a new part/vehicle"
What is it that 'burps out of the top of the crankcase'???
What is it that 'burps out of the top of the crankcase'???
Thread Starter
Junior Member
Joined: Apr 2011
Posts: 55
Likes: 0
Model: Cherokee
It seems like some oil burbs out of the top or leaks out of the top of the crankcase. There's a valve body, maybe a breather, that is towards the rear of the top of the crankcase, towards the firewall. I can see where oil has leaked out of that and down the side of the engine over time.
Seasoned Member
Joined: Sep 2011
Posts: 464
Likes: 0
From: Muncie, Indiana
Year: 1998
Model: Cherokee
Engine: 4.0
Just went out and checked mine. It looks to be the cause of my oil leak thats running down the bottom of my filter. I knew it was since my gauge is pegged to the right as soon as I turn my jeep on. So it looks like ill be buying a new one in the next day or so
Herp Derp Jerp
Joined: Nov 2011
Posts: 18,251
Likes: 17
From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
It seems like some oil burbs out of the top or leaks out of the top of the crankcase. There's a valve body, maybe a breather, that is towards the rear of the top of the crankcase, towards the firewall. I can see where oil has leaked out of that and down the side of the engine over time.
Thread Starter
Junior Member
Joined: Apr 2011
Posts: 55
Likes: 0
Model: Cherokee
Yes sir, that sounds about right. It could be a vent. How do I replace it and is there a write up on it? THANKS!! See, this is why I come here, I keep learning new things.
Herp Derp Jerp
Joined: Nov 2011
Posts: 18,251
Likes: 17
From: Parham, ON
Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II