Hi. I'm new to Jeeps with my 2000 XJ 4.0 Orvis (don't know if you had them in the States - it was the top of the range UK model 14 years ago).
I picked it up just over a week ago with just 77,000 on the clock and immaculate bodywork but it has been neglected for the last 3 years - only driven a few thousand miles but no servicing.
I've started out with fresh oil, filters, rad flush and it seems to be free of any major issues, so far.
My background is with Saabs, so I like an interesting vehicle and don't mind a few niggles as long as my car has a bit of character.
I just have a few typical new guy questions that some of you might be able to help me with...
1. When I bought it there was a coating of old oil on the lower half of the engine - not a huge amount and not dripping off. I figure that's reasonable for a 14 year old car. Now that I've changed the oil there is a little bit more oil weeping out and a slight drip working it's way down the outside of the pan and onto my driveway. Is this likely to just be because the fresh 10w40 semi-synth I used is thinner than the gloopy crap that was bunging the engine up and has dissolved the old oil that was plugging any minor weeps? Would you recommend new gaskets and bolts and a tighten up or live with it and leave well alone?
2. When it's running, every 10 seconds or so a kind of grating noise kicks in for 10 seconds then shuts off. I've isolated it to the area under the air intake resonator but can't figure out if it's some kind of pump or what. Any ideas? Not worried - just interested.

I'll leave it there for now before you all stop reading, but expect me back with more questions soon.

Thanks

Rich

 

Rich, Salad is right on about this.

Here's a little something to help you diagnose your leak.






I'd be looking up ABOVE first, and VERIFYING the source of the oil leak YOURSELF.

Everybody, who doesn't own or have to pay for or perform your vehicle repairs, loves to poke their noggin UNDER the Jeep and come out bearing the false bad news that your RMS is leaking.

Many mechanics, friends, people on Jeep forums who can’t see your Jeep from where they’re at, and good old Uncle Bob seem to enjoy telling you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it?

A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight and a dim flashlight, you’re good to go on your own. Don't jump on the RMS/oil pan gasket bandwagon right off the bat.

Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons.

First off, the engine sits nose-up and any oil will run back to the RMS area. Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber's adage apply here. "$hit flows downhill".

Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first.

Revised 02-26-2013

 

Wow a Brit with a 4.0L. That's got to be expensive to drive! Indeed we never got the Orvis, nor a fee other trim lines.

For point #1, it is likely because you got fresh oil into it. On the 4.0L leaks tend to form above and drip their way down. The valve cover gasket is a very common problem now that they're all 13+ years old and easy to do yourself, for that reason and the head baking off a lot of oil I recommend just tackling it anyway. Fel-Pro PermaDry is a fantastic unit that everyone here uses. Do a quick search for a writeup if you like. If the fresh oil persists the next step is to get all that filth off with some degreaser and find the source of the leak. It may be the oil filter adapter or the pan itself.

As for #2 I can't remember the differences in RHD under-hood layout. On LHD models the only movif parts near the air box are the power steering and auxilliary fan. The fan will come on with temperature and high refrigerant pressure when the A/C is used. Defrost engages the A/C on these things.

Welcome to CF!

 

Cheers for the welcome and the suggestions.
Not had the chance yet this week to get right in and have a good look, but a quick inspection makes me think you're right. The source could well be a leaky gasket under the top cover. Fingers crossed!
I really can't isolate the grating noise any more than I've already tried. It's definitely not a fan or the power steering pump. It kicks in for about 5 seconds, stops, then repeats when I'm watching the engine bay with nobody in the car. It's in the area of the throttle body, I think, right under the resonator.
Next question - I've got the 0331 head, but not not Tupy.
Do they all go bang eventually? My pressures are fine and fluids are all uncontaminated. If I really look after it will it jeep going OK?

 

Oh! You actually have a proper resonator! I had no idea XJs were ever equipped with those.

No fans there. Only moving part I can think of is the Idle Air Controller. It's a plunger on a stepper motor on the engine-side of the throttle body. If its making noise you should be able to feel it through your fingers.

Some maintain that all 0331s crack. I think take the best care of the cooling system you can, an remain vigilant for disappearing coolant and oil contamination, and just hope for the best.

 

Purely by chance I've discovered that the intermittent grating only occurs when the heating/ventilation system is active. When it is on, even if the A/C is not, I get the grating I described. Switch all the ventilation off and the noise goes away. Still no idea exactly what it is though.
I'd be happy to run with the vents off but the driver's window doesn't always work.
I beginning to think this Cherokee had even more character than my old Saab. Gotta love it!

 

Try tightening all your valve cover bolts(11mm) deep socket works well

 

It's 7/16" socket.

 

If in Defrost mode, the AC compressor cycles to de-humidify the air.

 

Hey Nottingham do you have a Mechanic's stethescope? I remember now that RHD has the blower motor on the same side as the intake manifold... sound could bounce around easily. Try listening with something against the firewall.