QuickNDirty

The knock/tap I have has been there since I bought the XJ. I have to try to listen for it or I don't notice it, most noticeable when under the oil pan drain plug. It is very hard to hear around 1000RPM and I can't hear it after that. It hasn't gotten any better or worse in the last 5k miles or so, so I chalked it up to "old 4.0s are noisy and make noises like that."

I checked my oil when pumping gas yesterday (as I usually do) and found some metal shavings on the end which were attracted by a magnet and about shat myself. That hasn't been there before. Another new thing was a whirring squealy type of deal that sounded to me like a pulley on the way out, but that went away as I was pulling out of the parking lot so I figured it safe to drive home.

I started researching like crazy and found some inconclusive rod knock suspect videos that kinda sound similar to what I hear, and I found a thread here where a member with a similar sound found it was an exhaust leak.

Another thread about the timing chain cover getting eaten by the chain and/or the tensioner, which could explain the stuff sticking to my slightly magnetized dipstick.

So I'm on a mission to find what's making that noise and to determine if my engine with 90k miles on it is fubar.

I removed the oil filter and cut it open with some diagonal cutters (major PITA, btw), ripped out some sections and spread it out. The valleys are full of crud which I honestly can't tell wtf it is. It is about as fine as beach sand and kinda feels similar, and is not attracted to magnets. I scraped some out and washed it in a paper towel and played around with it a bit. No nice shiny things, just nasty black sludgy sandy type stuff. I'll post some pics when I get a chance.

Incidentally, I took the XJ to the beach on Friday. Is it possible this sludge crud is beach sand that got sucked in through a vacuum leak or something? I wasn't doing anything crazy out there, just cruising at about 10mph for a couple of hours.

I planned to drop the oil pan tonight but got caught up with work, so I'll do that tomorrow hopefully. I'm really hoping my 4.0 is OK. I've babied it since I got it, but maybe that was 84k miles too late?

Just looking for some guidance on what to check/how to check it outside of the rod bearings, timing chain/cover, oil filter, etc.

Thanks.

ETA - Any of you guys use Linux? This reminds me a lot of how it was when I first started playing with Linux. Working on the XJ reminds me a lot of installing and configuring Slackware as my first *nix OS, except all that stuff is free.

BlueRidgeMark

That's seriously ugly.



That's your next step, I think. See what's in there.



I see the resemblance!

QuickNDirty

Got the pan off. People say that's hard to do with a minimal lift, but all I did was undo all the bolts, slide it forward a bit, rotate it maybe a degree or so towards the exhaust, a little more forward to get it past the starter, undo the rotate, slide it back and out toward the tranny.

I was half expecting to see chunks of piston skirt or something in there. What I did see was maybe 8 or 10 grams of that crap in the oil filter collected at the drain plug, and with the light just right, I could see a small amount of some sparkly things which I presume to be aluminum particulate, but not in an alarming (to me) quantity.

Still don't know what the hell that sludge is. I guess if it's plastic and I hit it with the torch I should be able to tell.

I didn't get to take the caps off to check the bearings because it was about to start raining, so I went ahead and partially bolted the oil pan back on and will wait til later to get it back off.

One thing that I'm pretty sure is bad news, is that I can wiggle all the rods horizontally on the shaft. There's no up/down play that I can perceive, but side to side has hundredths of an inch of play and can be made to clack with little effort.


Here's some pics so far. Kind of a mess, if there are any other pictures anyone wants to see I'll take them. That jet black oil is 1000 miles old, btw.

QuickNDirty

Metal shavings were coming from the dipstick tube. Took care of that with a bore snake.

Sludge stuff I guess is carbon buildup and dirt. The oil pan had a thick coating of that crap all over it. The old oil pan gasket was a one piece grey thing. Not sure if that's factory or not.

Checked all the rod bearings and the crank and everything looked really good. I even got a second opinion from my neighbor who used to do engine work professionally. He also said the axial play I had was acceptable.

Still have a noisy engine, but I bought one of those stethoscopes and the place where the tapping was loudest was around cylinder 2 on the valve cover. I'll check under there next time I get a chance.

I think I tracked down the source of the whirring squealies, too. Think it may be the bearing in the power steering pump. Sounds pretty nasty with the stethoscope on it.

I didn't check the timing chain well, yet, but I did poke around at it with the oil pan off and it didn't seem sloppy on either side.

Time for beer.

BlueRidgeMark

Interesting. When you say the metal shavings came from the dip stick, what exactly does that mean?

QuickNDirty

With the pan off, I ran the stick through the tube, and there were metal shavings on the end of the stick.

The dip stick doesn't go into that tube very well. I guess it could be gouging the wall and that's where the shavings come from.

BlueRidgeMark

That's odd. I'd get another dipstick.

Come to think of it, we have plenty of them in Washington D.C. that you can have!

QuickNDirty

I don't want to go shoving dirty stuff into my oil pan after all I did to clean it.

BlueRidgeMark

JSJJ388

Im having a sound that seems to be similar to this. Have not pulled the oil pan yet but I might. Did run seafoam through it but to no avail. Following to see what you come up with.