Tales From The Oil Pan. - Now With Video

Well I dropped the pan and it’s a very short story.

Had the usual small amount of fine metal particles and this one larger (but still tiny) chunk.



I’ve put only 5000 miles one it but the PO seemed to have changed only the #6 piston.
The rods all had a small amount of side to side play. Nothing loose or large difference between the Rods.




The rest of the story-

The engine started knocking on my recent trip to the Smokies. Not constant in the beginning but I could definitely feel a little loss of power each knock. It kept getting worse during the 6 day trip. The engine was down maybe 25-30% of power by the end. (Over 400 miles of mostly road driving).

I checked the timing was right on at 5*. The plugs were about the same as usual- rich on the passenger side lean(ish) on the driver side.

Oil pressure hasn’t changed. 10-15 lbs When idling warm and 25lbs at 50mph or above.

What do y’all think?

 

What type of metal is the chunk? (magnetic or not, etc?)

Still has pressure, but loosing power... cam related?

 

One thing I changed before the trip was the distributor cap. I don’t remember if the numbers on the old cap corresponded to the correct cylinder but it is definitely off by one cylinder now. It’s a regular odd fire cap with even spaced pickups on the inside. I’ve triple checked the timing and quadruple checked the wires are to the correct cylinders.

 

Interesting, not metal/magnetic at all. Then I tapped it with the hammer and dust. Carbon deposit flaked off.

 

It's worth doing compression and leak down tests.

Since one bank is different from the other, I would verify that's an odd-fire cap (but that wouldn't have gotten worse over the course of the trip).

You could also have a cam lobe going flat. Might be worth pulling the valve covers and see if any of the rockers are moving noticeably less than the others.

 

Did you ever pull a plug wire one at a time to see if you noticed anything different with the engine? The way the knock sounded and how it only does it under load made me think of the crankshaft. It's usually a dull metallic sound but a loss of oil pressure is usually noted. Does it make noise when you push the clutch in and out?

Another thing you can do is Rev the engine up and turn the key off until it almost stops and then turn it back on. Listen for a noise.

 

Would theses cause the knocking?

 

I'd wager even money you have some sort of ignition issue.
I've seen metal bits in pickups before. I'm convinced older engines occasionally shed casting flash. If it's not bearing material or ring pieces I wouldn't fret. I've been shocked by the lifter valley casting flash in some engines.

 

None of those items should cause a knock, but a knock won't cause a loss in power. Those tests are to assess if anything else is wrong with the motor. A flat cam might cause a tick, but not really a knock.

Like 73 cj5 said if the bottom end is going, usually the oil pressure will be low. You can pull a rod cap or two and see if there is any copper showing and/or use some plastigage to check clearances.

 

If you haven't had a motor apart before, be sure to keep the rod caps with the rod they came from and in the same orientation they were before. And of course, torque them properly when reassembling.

 

Scott,

73 cj5 shared your video with me. It sounds really bad and there is something seriously wrong.

If it were me, I'd pull the motor and disassemble it. The problem should be obvious once it's apart and I don't think it's anything you can fix in the Jeep.

At least you have a good core right now. Run it much longer and I'm not sure you'll have that.

 

If not magnetic I would look at the timing chain. May have stretched or dropped some teeth and jumped a tooth or two. Will effect cam timing causing manu of the symptoms you describe. Easy to check without disassembling much of anything.
Regarding connecting rod side play, there is a specification for that you can check with a simple feeler gauge.

 

If the timing is way off, pre-igntion or "detonation" knocking could be severe. And cause loss of power. But I'd expect the spark plugs to look "hot."

 

I forgot about the video.

 

yep . engine tear down . along with rod bearing knock . piston wrist pin will knock too
now that speedometer . pull cable and pump some graphite in it . one day it's going to hit 100 plus

 

Just to be sure... that is not an exhaust leak noise?

But at one point I did hear a deeper knock, like a bearing.

 

Tear into it. That’s a bad knock. The longer you go with it, the worse it will be on other components. Been there, done that, with my F134

 

Yes, or break off the needle from the bouncing.

 

yeah sounds like a bad case of spark knock to me. Its common for the original timing gear to eat itself. Thats what that piece is you found I think