Changed the oil and now the engine ticks.

The best way to test the oil pressure guage and wiring harness is to turn on the ignition key and short the wire on the sensor to the engine block, while a helper is watching the guage. No need to disconnect the wire from the guage. You should be able to use a screwdriver. If the guage and wiring harness is good, the pressure guage will go to 0 PSI. If it doesn't go to zero, you most likely have a problem with the harness.

My 1990 XJ was leaking a quart of oil every 1000 miles, mostly out the rear main seal. From what I read here, I suspected excess pressure in the crank case. I replaced the CCV hoses with a set from NAPA. I did a search here and found the NAPA part numbers posted here. With the new hoses the leaks are completly stopped. The NAPA parts cost me less than half the dealer price and fit real nice.

It is the small diameter plastic tube that attaches to the rear of the valve cover that is supposed to relieve the pressure. I would bet that tube on your engine is completly blocked. Pull it off and try to blow through it. Another symptom is oil on the rear of the oil filter element. This happens because the small tube gets plugged and the pressure is relieved into the air box, through the large diameter hose in the front of the valve cover. This is supposed to supply filtered air into the crank case. Since this hose goes to the air box, there is not enough vacuum to relieve the pressure, and there are no baffels to keep the oil from going out the hose.

I recently bought a 1987 XJ that leaks a quart every tank, mostly through the rear main, like yours. I plan to replace these hoses after I finish installing the lift kit. I hope I fare as well as I did on the 1990.

If you have a NAPA up there, try the hose kit, before you replace the rear main. Or, see if the small one is blocked, at least. Could save you a lot of time and put off the rear main replacement. The hard plastic tubes are probably original, old and brittle. If they are not broken, they will likely break the next time you bump one.

MoFo
 
Actually I have checked that before but I will check it again, the small one at the back of the rocker cover has been replaced by a peice of small diameter hard air line. I do want to replace the rubber grommet though as it is the metered orifice from what I understand.

Really though a bit of oil is the last of my problems right now though.
 
With the CCV though, it is very worth while doing the '00 hose upgrade for that very reason. I've done my '90 and has been great. Will be doing my '89 next.
 
Well I just changed the oil pressure sender. Unfortunatly my gauge is canadian so I can tell you it sitting at 4.5 whatevers. 3 is straight up on this gauge and it maxes out at 5.4. What is the Canadian gauge measured in?

Either way it seems the pressure is fine to me.

Ah a found a gauge sitting around that shows both.

Compared to this one it seems its measured in kPax100

So its sitting at about 65 psi at idle, cold. It moves a bit but not much when I rev it up a bit. Its about 39 Fahrenheit outside right now.
 
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Cold mine will sit around 1/2 to 2/3 of the way up. For what it costs just change the oil again. If you havent done it in over 10000kms the oil is bound to be pretty sludgy. By changing it again you have pretty much eliminated the chance of having a bad filter and you know there is no additives in it. By the way the Canadian Tire filters are frams. He make them in my home town. As far as a aditive I recomend Lucas products 100%. Really impressed with what I have seen rearding engines that have used it frequently.
 
For what it is worth...

I learned a little trick from an old dog Jeep mechanic that specialized in the older 4 cylinder post-military Jeeps. For your next 3 oil changes (which should be religously done at < 3,000 miles) try adding 1 quart of Dexron III auto tranny fluid 1 week prior to the oil change.

The addition won't cause any problems with your rear main seal, and the massive amount of detergent in the Dexron will scrub the crud from your block so it's nice and clean again. The proof is in the pudding though- try draining your 1st oil change through a cheap paint strainer, and report back what comes out- I was amazed by what I saw the 1st time I tried this, and I had dramatically less "junk" come out each time thereafter. At 130K miles, you would have thought I had just "broken in" the motor, from all the metallic schrapnel that got strained out.

I'm now at 230k miles, and I still have compression numbers better than factory spec. I read in an earlier post about checking out your CCV system, and I also agree. If the orifice plate in the rear of the valve cover gets plugged up, there will be enough blowby backpressure under throttle to do things like blow out your dipstick- which is only a little bit funny after fogging up the highway, just after you merged into the "fast lane". I'd pull the cover off the airbox, and see if your filter has big oil deposits. That would be the first sign that you've lost the vaccuum you need to keep pulling the blowby gasses back into the intake.

I chose to re-do all my vaccuum lines in soft hose, so the choice is up to you- just go back and re-check the lines for security/serviceability every 6 months or so.

Closing thought is that ALL 4 litres "tick" a little bit- it's their nature. I've gotten so used to mine when it's warm, that I'm a little suspicious when I hear a bone-stock Cherokee at the grocery store, and it DOESN'T make some kind of noise. I'm thankful that my Borla exhaust drowns out any other noises, like screams from the people that parked next to me...
 
George2 said:
The addition won't cause any problems with your rear main seal, and the massive amount of detergent in the Dexron will scrub the crud from your block so it's nice and clean again.
Click to expand...

WTF? ?

you just contracicted yourself there. i assume you meant the additive wont affect the actual seal material itself.

HOWEVER. . . the detergent aditives can/will promote leaks by removing build-up that might be keeping stuff sealed. thats EXACTLY why you dont fill an old, neglected trany with new fluid. it'll scrub the varnish off that the friction surfaces have been relying on and trany failure is quite common in those circumstances.

ATF is a good for cleaning your engine internally but i wouldnt do it on an engine that has questionable seals.
 
Why is everyone so concerned about the oil leak when I have bigger problems?

I'm not talking a huge leak here guys, I'm talking a couple quarters on the ground when I park sometimes. I've already helped a friend change his rear main in his 4.0 and should have no problems doing mine later this fall/winter.


My problem right now is the valve train ticking and now the puffing that I described earlier. I know the 4.0 can tick a bit, this isn't a bit, this is crazy loud to the point that I can hear it inside the jeep over the road noise. With the ticking calming down a bit but a new sound showing up to replace it, I have to assume something has been damaged.

I own 2 XJs and have 2 friends that own XJs all with 4.0. I know what they sound like and this isn't normal and no one that has heard it has thought it was. I've also been running this one for a year and its never sounded like this.

I really wish i had a way of recording the sound and putting it up for you guys to hear.
 
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Personally, if it were my XJ I would change the oil again to see if the noise disappears. Upgrade to a good quality semi-synthetic and the absolute highest quality oil filter you can find and then see if the noise remains.
 
Well I pulled the rocker cover and it isn't pretty.

The pushrod blew through the rocker on the 4th cylinder back from the front of the engine on the intake port.

So where do I go from here? I can get another rocker off a used engine but first I want to know what caused it.

Me and a friend are thinking its breathing funny because its breathing through the exhaust port or possibly a hole in the piston if they touched.
 
Spanky414 said:
Well I pulled the rocker cover and it isn't pretty.

The pushrod blew through the rocker on the 4th cylinder back from the front of the engine on the intake port.

So where do I go from here? I can get another rocker off a used engine but first I want to know what caused it.

Me and a friend are thinking its breathing funny because its breathing through the exhaust port or possibly a hole in the piston if they touched.
Click to expand...
You can't tell nutton until you replace the pushrod and rocker.
It fail because it wasn't getting oil.
 
I took a look in through the spark plug hole and piston doesn't seem to be damaged at all. As much as I can tell through that hole of course.

So you guys are thinking that I should just replace that rod and rocker and see if it still ticks?


I thought the ticking was probably a collapsed or stuck lifter?

I know it sounds crazy but could I drive it with that rocker and pushrod pulled out and the fuel injector and plug wires disconnected from that cylinder?

Its going to rain all week I can could really use it for the week and then work on it next weekend when it stops raining (supposed to rain all this week here).
 
OK so we put in another rocker and pushrod, then we cranked over the engine with the coil wire unplugged. Everything looked and sounded good.

Then we did a compression test on that cylinder and it was around 115-120 PSI.

Then we put back in the spark plug and coil wire and fired it up. Sounds great, no ticking and rockers all seem to be moving nice. We left the rocker cover off for all this.

BUT there is no oil coming out of the pushrods to oil the rockers. None at all. We aren't sure how much is supposed to be coming out but are guessing there should at least be a trickle.

THe oil pressure gauge is still showing above half. so about 50-65psi.


Also the whole head under the rocker arm cover is just caked in dried and half dried oil, all sludeged up and flaky, definatly alot nastier then I thought it would be.
 
We were thinking of that but I'm wondering if it would do much cause if its plugged then its not getting anything through so how would it get to the plug? Wouldn't the oil and crap already in there be in the way of the flush? Remember NOTHING is coming through the pushrods.

If the engine is running quiet we are assuming that the lifter bores and crank and cam shaft are being properly oiled. So that means all the lifters are clogged?

Can someone explain how the lifters oil the pushrods and rockers?

Here is a discription from the FSM.

"Oil is supplied through the full-flow oil filter
and into an internal oil passage. Internal passage provides oil to the
lifter bores. Oil is then routed to camshaft and crankshaft bearings.
Oil is supplied to rocker arms from the hydraulic lifters and through
the push rods."

But I would love a diagram and further detail.
 
The pushrod is hollow. The lifter actually pumps oil up through the pushrod. When it gets to the top, it spills through the little hole in the rocker and flows down to oil the pivot point on the rocker. It is splashed everywhere else to lubricate the valve guides. This is why it is important to flush the push rods to make sure there are no obstructions. The lifter may be crudded up and not pumping much oil. I have used the ATF technique. In severe cases I have used two quarts of ATF, a quart of diesel, and two quarts of 30W along with a fresh filter. I run it for an hour or two drain it, and install a new filter.
 
Spanky414 said:
Well napa didn't have any of the Gold versions of their filters. Any other recomendations?

As I said before how are the carquest filters? Or just a normal name brand I can look for?
Click to expand...

Out of stock? sheesh........the silvers are good as well if they aren't out of them as well. Never heard of the carquest ones so can't give an opinion on them. Sorry.
 
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