Jeep losing oil pressure? Here's why ...
 

My oil pressure is 20psi at 2000rpm's and up. At idle I get 8psi on a
mechanical gauge, but zero on my electrical gauge.

I've changed the oil sensor and oil pump, only to discover the reason
I lose oil pressure in my 1997 2.5L Jeep Wrangler TJ is because the
cam bearings are wearing out. The crank & rod bearings didn't fix the
problem, so the only thing left is the cam.

So far no good internet posts reveal this as a cause of oil pressure
loss in Wranglers, so I'm posting this for information to all those
other Jeep owners who have the same problem.

Good luck, the cam is not the overhead type! It's buried inside.

Re: Jeep losing oil pressure? Here's why ...
 

TheWarman wrote:

> My oil pressure is 20psi at 2000rpm's and up. At idle I get 8psi on a
> mechanical gauge, but zero on my electrical gauge.
>
> I've changed the oil sensor and oil pump, only to discover the reason
> I lose oil pressure in my 1997 2.5L Jeep Wrangler TJ is because the
> cam bearings are wearing out. The crank & rod bearings didn't fix the
> problem, so the only thing left is the cam.
>
> So far no good internet posts reveal this as a cause of oil pressure
> loss in Wranglers, so I'm posting this for information to all those
> other Jeep owners who have the same problem.
>
> Good luck, the cam is not the overhead type! It's buried inside.


thats odd. your crank could need resurfacing, does it appear that way?
how many miles? my expirences are that cam bearings are not really the
fist to go, they get oil pressure first.

how bad did the bearing inserts look that you replaced?

Re: Jeep losing oil pressure? Here's why ...
 

TheWarman wrote:

> My oil pressure is 20psi at 2000rpm's and up. At idle I get 8psi on a
> mechanical gauge, but zero on my electrical gauge.
>
> I've changed the oil sensor and oil pump, only to discover the reason
> I lose oil pressure in my 1997 2.5L Jeep Wrangler TJ is because the
> cam bearings are wearing out. The crank & rod bearings didn't fix the
> problem, so the only thing left is the cam.
>
> So far no good internet posts reveal this as a cause of oil pressure
> loss in Wranglers, so I'm posting this for information to all those
> other Jeep owners who have the same problem.
>
> Good luck, the cam is not the overhead type! It's buried inside.


thats odd. your crank could need resurfacing, does it appear that way?
how many miles? my expirences are that cam bearings are not really the
fist to go, they get oil pressure first.

how bad did the bearing inserts look that you replaced?

Re: Jeep losing oil pressure? Here's why ...
 

TheWarman wrote:

> My oil pressure is 20psi at 2000rpm's and up. At idle I get 8psi on a
> mechanical gauge, but zero on my electrical gauge.
>
> I've changed the oil sensor and oil pump, only to discover the reason
> I lose oil pressure in my 1997 2.5L Jeep Wrangler TJ is because the
> cam bearings are wearing out. The crank & rod bearings didn't fix the
> problem, so the only thing left is the cam.
>
> So far no good internet posts reveal this as a cause of oil pressure
> loss in Wranglers, so I'm posting this for information to all those
> other Jeep owners who have the same problem.
>
> Good luck, the cam is not the overhead type! It's buried inside.


thats odd. your crank could need resurfacing, does it appear that way?
how many miles? my expirences are that cam bearings are not really the
fist to go, they get oil pressure first.

how bad did the bearing inserts look that you replaced?

Re: Jeep losing oil pressure? Here's why ...
 

I have one of these engines with 60,000 miles, and the oil pressure is just
fine thank you. How did you know to replace the main and rod bearings, and
did you check clearance with plastigage when you had the caps off? (The
following link may be helpful.)

http://www.dana.com/perfectcircle/Plastigage.htm

You may have a worn crank, incorrect size bearing inserts, a worn oil pump,
or cam bearings as you say. You may also have any of a number of "really
obscure" problems such as a misaligned gasket or improperly drilled oil
passage.

Be advised that replacement of cam bearings is an "expert" procedure
requiring special tools and rarely done with the engine in the vehicle. :o(

Earle

"TheWarman" <thewarman@yahoo.com> wrote in message
news:91bb83f6.0310270718.7f1f6d99@posting.google.c om...
> My oil pressure is 20psi at 2000rpm's and up. At idle I get 8psi on a
> mechanical gauge, but zero on my electrical gauge.
>
> I've changed the oil sensor and oil pump, only to discover the reason
> I lose oil pressure in my 1997 2.5L Jeep Wrangler TJ is because the
> cam bearings are wearing out. The crank & rod bearings didn't fix the
> problem, so the only thing left is the cam.
>
> So far no good internet posts reveal this as a cause of oil pressure
> loss in Wranglers, so I'm posting this for information to all those
> other Jeep owners who have the same problem.
>
> Good luck, the cam is not the overhead type! It's buried inside.

Re: Jeep losing oil pressure? Here's why ...
 

I have one of these engines with 60,000 miles, and the oil pressure is just
fine thank you. How did you know to replace the main and rod bearings, and
did you check clearance with plastigage when you had the caps off? (The
following link may be helpful.)

http://www.dana.com/perfectcircle/Plastigage.htm

You may have a worn crank, incorrect size bearing inserts, a worn oil pump,
or cam bearings as you say. You may also have any of a number of "really
obscure" problems such as a misaligned gasket or improperly drilled oil
passage.

Be advised that replacement of cam bearings is an "expert" procedure
requiring special tools and rarely done with the engine in the vehicle. :o(

Earle

"TheWarman" <thewarman@yahoo.com> wrote in message
news:91bb83f6.0310270718.7f1f6d99@posting.google.c om...
> My oil pressure is 20psi at 2000rpm's and up. At idle I get 8psi on a
> mechanical gauge, but zero on my electrical gauge.
>
> I've changed the oil sensor and oil pump, only to discover the reason
> I lose oil pressure in my 1997 2.5L Jeep Wrangler TJ is because the
> cam bearings are wearing out. The crank & rod bearings didn't fix the
> problem, so the only thing left is the cam.
>
> So far no good internet posts reveal this as a cause of oil pressure
> loss in Wranglers, so I'm posting this for information to all those
> other Jeep owners who have the same problem.
>
> Good luck, the cam is not the overhead type! It's buried inside.

Re: Jeep losing oil pressure? Here's why ...
 

I have one of these engines with 60,000 miles, and the oil pressure is just
fine thank you. How did you know to replace the main and rod bearings, and
did you check clearance with plastigage when you had the caps off? (The
following link may be helpful.)

http://www.dana.com/perfectcircle/Plastigage.htm

You may have a worn crank, incorrect size bearing inserts, a worn oil pump,
or cam bearings as you say. You may also have any of a number of "really
obscure" problems such as a misaligned gasket or improperly drilled oil
passage.

Be advised that replacement of cam bearings is an "expert" procedure
requiring special tools and rarely done with the engine in the vehicle. :o(

Earle

"TheWarman" <thewarman@yahoo.com> wrote in message
news:91bb83f6.0310270718.7f1f6d99@posting.google.c om...
> My oil pressure is 20psi at 2000rpm's and up. At idle I get 8psi on a
> mechanical gauge, but zero on my electrical gauge.
>
> I've changed the oil sensor and oil pump, only to discover the reason
> I lose oil pressure in my 1997 2.5L Jeep Wrangler TJ is because the
> cam bearings are wearing out. The crank & rod bearings didn't fix the
> problem, so the only thing left is the cam.
>
> So far no good internet posts reveal this as a cause of oil pressure
> loss in Wranglers, so I'm posting this for information to all those
> other Jeep owners who have the same problem.
>
> Good luck, the cam is not the overhead type! It's buried inside.

Re: Jeep losing oil pressure? Here's why ...
 

That is a strange one....

Did you see an increase when you replaced the crank bearings?

If not, then I would be suspecting something other than bearings.
Usually the bottom end wears out way before the crank bearings.

Could the pressure bypass valve on the oil filter maybe have blown out?

Is there an oil channel pressure plug on the front of the block under
the timing cover that maybe fell out?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

TheWarman wrote:
>
> My oil pressure is 20psi at 2000rpm's and up. At idle I get 8psi on a
> mechanical gauge, but zero on my electrical gauge.
>
> I've changed the oil sensor and oil pump, only to discover the reason
> I lose oil pressure in my 1997 2.5L Jeep Wrangler TJ is because the
> cam bearings are wearing out. The crank & rod bearings didn't fix the
> problem, so the only thing left is the cam.
>
> So far no good internet posts reveal this as a cause of oil pressure
> loss in Wranglers, so I'm posting this for information to all those
> other Jeep owners who have the same problem.
>
> Good luck, the cam is not the overhead type! It's buried inside.

Re: Jeep losing oil pressure? Here's why ...
 

That is a strange one....

Did you see an increase when you replaced the crank bearings?

If not, then I would be suspecting something other than bearings.
Usually the bottom end wears out way before the crank bearings.

Could the pressure bypass valve on the oil filter maybe have blown out?

Is there an oil channel pressure plug on the front of the block under
the timing cover that maybe fell out?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

TheWarman wrote:
>
> My oil pressure is 20psi at 2000rpm's and up. At idle I get 8psi on a
> mechanical gauge, but zero on my electrical gauge.
>
> I've changed the oil sensor and oil pump, only to discover the reason
> I lose oil pressure in my 1997 2.5L Jeep Wrangler TJ is because the
> cam bearings are wearing out. The crank & rod bearings didn't fix the
> problem, so the only thing left is the cam.
>
> So far no good internet posts reveal this as a cause of oil pressure
> loss in Wranglers, so I'm posting this for information to all those
> other Jeep owners who have the same problem.
>
> Good luck, the cam is not the overhead type! It's buried inside.

Re: Jeep losing oil pressure? Here's why ...
 

That is a strange one....

Did you see an increase when you replaced the crank bearings?

If not, then I would be suspecting something other than bearings.
Usually the bottom end wears out way before the crank bearings.

Could the pressure bypass valve on the oil filter maybe have blown out?

Is there an oil channel pressure plug on the front of the block under
the timing cover that maybe fell out?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's

TheWarman wrote:
>
> My oil pressure is 20psi at 2000rpm's and up. At idle I get 8psi on a
> mechanical gauge, but zero on my electrical gauge.
>
> I've changed the oil sensor and oil pump, only to discover the reason
> I lose oil pressure in my 1997 2.5L Jeep Wrangler TJ is because the
> cam bearings are wearing out. The crank & rod bearings didn't fix the
> problem, so the only thing left is the cam.
>
> So far no good internet posts reveal this as a cause of oil pressure
> loss in Wranglers, so I'm posting this for information to all those
> other Jeep owners who have the same problem.
>
> Good luck, the cam is not the overhead type! It's buried inside.