I searched for this topic and found a few people with the same issue, however I wanted to let you guys know about my specific problem to see what you guys thought, because I know there are A LOT of smart people here.

My engine started "ticking" just the other day, the morning after I did an oil change! I have always used a FRAM filter with Castrol GTX 10w-30 oil, and did so this time. It has been unusually cold here in CA during the nights and it seems to do it when it's cold. It also tends to go away when I rev up the engine a little...

My XJ does have 270k miles, I haven't noticed a loss in power at all which I'm thankfull for, but I'm worried that I will if I don't fix it....

I've read some posts saying it's caused by a gap between the camshaft lobes and rocker arm from wear due to the newer oils....

I also noticed driving to work today that the oil pressure gauge was mostly in the high 40's, seemed to go down a little after it was warmed up, but I've also read that the XJ's oil pressure gauge is innacurate and to not trust it...

Any thought on this is much appreciated! Thanks ahead of time guys!

 

has the oil pump ever been replaced?

 

Possible exhaust leak? I know the stock manifolds are prone to cracking, you might want to check that out.

 

You probably got a sticky lifter, thats what it sounds like to me. A lot of XJ's do, because the lifters sit vertically in the block and contaminants are prone to getting trapped in there. I've got the same problem when I'm cold, one valve tick that goes away when the temp reaches about 175 degrees. Your oil pressure sounds normal for 270K. 4.0l's have hydraulic lifters so if there are any gaps they are automatically taken up, unless the lifter isn't holding pressure, or sticky. The quality of oils has improved over the years.

I don't recommend FRAM filters to anyone, everything I've read about them puts them at the bottom of the barrel in filtration and flow. I also heard they got in trouble in the 90's because the only FRAM filters meeting OEM specs, where the top shelf ones. If somebody has more info on this, please chime in.

 

check the gap's between your rockers and lifters with "feeler" guages(long thin pieces of metal). find out what the spec is and make sure the gap is correct. you want to have to it be a tight fit. to where you have to push it in the gap and pull it out, not just slide in and out (hot dog down a hallway anyone!) heres a link to what the feeler gauges look like..better yet a picture. good luck

 

no FRAM filters.... that's sad I thought they were a good company + I love the black grippy paint so you can get a good grip when the times comes to take it off.
Thank you EVcherokee!

 

I've also heard of the injectors making a "ticking" noise.... what would cause this?

 

Noisy injectors. I think it's just where they are all close together, they're usually open/close function is more audible. Same thing in my friends 96 Explorer, and another friends Cheby. As long as you're not hearing anything smacking or grinding, your oil pressure is between 20-25 at idle, and you're not blowing smoke, then you're 4.0 is healthy.

 

There is no spec. Hydraulic lifters require no adjustment, just torque the rocker arms down and your good.

Also theres a pushrod between the lifter and the rocker and valve lash is measured between the valve tip and rocker tip. The proper tool to use are call "go-no go" feeler gauges. The front half is a different thickness than the back half. Once you select the right gauge, the front should freely fit between the rocker tip and valve tip, but the back half shouldn't at all. This measurement is also taken when the cam lobe is at its lowest point, usually 180 degrees from the peak of the lobe.

Don't mean to blast you apart, just trying to keep the wrong info from getting around.

 

Also, to help a little with that lifter tick, I use Engine Flush every now and then with my oil change. Just put it in, let the rig IDLE ONLY for 5 minutes. Then drain. It actually does wonders.

 

I will try some of this an let you guys know what happens.... thanks again!

 

477000+ km on the 4.0L and still running 1000+km per week. Filter and oil change monthly(every 5-6000km) I always use the Fram, no problem. The Castrol GTX is fine as are any of the name brands. The pressure is normally higher on fresh oil, also on cold start up. If your gauge is staight up at 12 oclock position when you are running your ok, it will drop at idle. Best oil for me has been Valvoline and Quaker State HI Mileage (consistently higher pressures thru the life of the oil) I have no problem with the Castrol or Penzoil products either. I recommend do not use bargain brands.
To me the good oil keeps pressure during my 3 to 4 hour runs and thru the life of the oil, always change your filter when you change your oil.

 

Oil manufactures have reduced the zinc content of motor oil to increase the life of catalytic converters. The primary function of the zinc is for lubing the cam/flat tappet surface. Since most modern engines are running roller lifters the need for zinc is no longer necessary.

You can buy zinc additives, high mileage "blended" oils or add 1/2 qt of STP to each oil change to compensate for the missing zinc.

 

Thank you guys for all your input again!

I wanted to update you all on this "issue"

After closer inspection of the fuel injectors, I noticed a VERY slight leak on the very rear injector (Cyl 6 I think[Going from front to back])
So I popped into PepBoys, luckily they had ONE left.
When I removed the fuel rail and injectors I noticed A LOT of nasty build-up around the inside of the injector ports so I cleaned them up.
After replacing the injector and the fuel rail, I started her up, the "ticking" was gone!
I'm thinking the injector was completely clogged and NO fuel was getting into cyl #6
Would this cause it to "tick?"
Regardless she runs PERFECT once again.

THANKS AGAIN!
~Regards,
Ender