nmillard

OK, I just bought this 2000 XJ sight unseen. I new it had problems, but I thought they were all typical Jeep problems. First thing, the oil pressure drops to zero after warming up for a bit. I pulled off the valve cover to replace the gasket (it leaked of course), and the sludge build up inside was amazing. I have never seen it before....it looked like chocolate pudding covering everything. I did my best to clean it up, and I am running oil through right now, and I will drain it again tomorrow. I replaced the oil pressure sensor unit, but the oil pressure still drops to zero after the engine warms up when it idles. The engine got 22MPG when I drove it back from where I bought it. It passed smog. The engine is a little noisy (clicking sounds). It sounds like the lifters. Any thoughts on what next for the oil pressure? I was told to run some ATF fluid through the engine for a couple hundred miles, and then replace out with synthetic and see if the noise lessens over time. Also, I changed the spark plugs and they were gapped too large, and they looked like they had been replaced in a very long time.

Firestorm500

The oil pump and/or screen could be clogged with sludge.

Or the main and rod bearings are worn out.

The ticking sound is either the injectors or the lifters.

Sounds like lack of maintenance killed this engine.

How much is a new engine? A rebuilt Jasper engine is about $3400 + R&R labor.

Don't waste your time and money running ATF and synthetic oil through it.

You might want to sell it.

Your first loss will be your cheapest loss.

And consider it a lesson learned.

OverlandZJ

Pics of the top of the cylinder head?

You have an 00 XJ with the 0331 head, it's possible your "sludge" is a bad head gasket or cracked head allowing water to mix with the oil. Typical old oil sludge would be a dark solid deposit, sounds like you have other issues.

lfhoward

There are several different possible explanations for your low oil pressure, from a bad oil pump on the easy to fix end of the spectrum, to a cracked head leading to coolant mixing with oil and wearing out your engine bearings (the very bad end). I just replaced the cylinder head in my 2000, but I caught the problem before too much bearing damage occurred. When the bearings get worn down, the engine can't hold oil pressure, especially when it's hot and idling. Replacing your engine bearings entails pulling the engine to rebuild it. :-( I hope that's not what's going on, but search for '0331 cracked head' to get a background on this issue and how it happens. This problem affects 2000 and 2001 XJ's. Sorry to be the bearer of possible bad news!

Bustedback

I would shop around for a long block and then enjoy hundreds of thousands of care free miles with said new long block installed.

duncan807

check this out may help may not
https://www.cherokeeforum.com/f51/ho...e-works-82130/

tjwalker

Get a "mechanical" gauge. They can be rented from some parts store. Hook it up and compare what you get to what you see on your dash gauge. I know you installed a sending unit, but you need to rule out the gauge before looking elsewhere. Good data = Good decisions.

A verified low oil pressure situation is because of lack of proper clearances in some hardware in the engine. It might be the oil pump, or the engine bearings, or both. When clearances become too large, proper pressure cannot be maintained.

And keep a super close eagle eye on the coolant level in the reservoir. The #1 symptom of a cracked 0331 cylinder head is "unexplained coolant loss".

If this looks like a money pit engine, I'd look around for a replacement. An engine is a component. A large one, but one that can be swapped out relatively easily. I recommend salvage yard engines to keep costs reasonable. You can get upside down on your XJ real quickly with lots of engine repairs, and a salvage yard engine is plug and play.

Good luck!

Firestorm500

Better hear that SY engine run before you swap it in. It may be worse than yours.

And make sure it's compatible with your year model Jeep. Not everything interchanges.

Word to the wise: sell it now if you can't afford to work on it OR you just don't want to get that deep into it. Jeep built plenty of these things.

nmillard

Yeah, I am afraid to put much more money into it because I know it might not be worth it. I will have the mechanical read done today and go from there. Sucks for sure. Thanks for all the good tips.

Nate

Northwoods Snowman

Selling it should depend on what you have into it so far, and what condition the rest of the vehicle is in. If everything else is great, and you just need to do an engine swap, you might be ahead, depending on what you have into it. Granted, if you're an honest person, it's hard to sell a vehicle that you know is a ticking time bomb and recoup much money out of it.

Main bearings can be changed with the engine still in the vehicle too.

puredrive

If I was in this predicament..I would do en engine flush first.

http://www.amsoil.com/storefront/flsh.aspx.

Then look into the a mechanical oil pressure to verify it. Replace the the oil pump and see if that changes anything.

Total cost would be about 150 or so for parts.

a737mech

what you need to do is buy seafoam and new oil add oil with a 1/4 bottle sea foam run 300 miles and repeat 3 more times after this then buy a can of kerocene 1 gaal drain oil add runn 10 min. at 12-1500 rpms and drain new filter and add new oil sludge should be gone!

Northwoods Snowman

Kerosene is a BAD idea. It will clean out the engine, but it doesn't provide any lubrication. It acts as a solvent and disolves the oil. It works great when you have the engine apart, but you never want to run an engine with it substituting for oil.

Bluemax

a gal of kerosene?? thats sounds a bit much! i use half a quart every now and then wheni change my oil. run it maybe 5-6 mins!. A gal of kerosene is way to much

Firestorm500

ya, sludge gone along with every bearing in the engine. rings scuffing cylinder walls.

i wouldn't buy a used vehicle from this guy, would you?