Grit on oil drain plug

JRK58 did pass the time by typing:

I wouldn't be. A few bits of metal are usually in any oil pan. Depends on the casting or if small burrs have come loose.

Thanks for the reply Doug, I was thinking bits of casting. They are black with no shine under a magnifying glass.

No. What you should really worry about is the non-ferrous metal used in the crank bearings. That is soft and non-magnetic, and you won't know that it is gone, until it is too late. ;^)

Earle

That likely was a magnetic oil bolt Bill.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >

It is a magnetic bolt, I was planning on a trip ( 700 miles RT) in a few weeks which is one of the reasons I bought it. I did notice a faintly audible knock for a few minutes this morning when I first started it up, I could only hear it when I was inside with the doors shut. I couldn't hear it with the hood lifted. I paid 9500.00, 29K miles it looks new ( stored in heated garage) and has the Z package,

5.2. I guess it's still an ok deal even if I have to pay a few K for a rebuild but I sure hope I don't have to.

J Kennedy

The stuff that wears out isn't magnetic....

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >

Not unusual, and generally nothing to worry about.

Then I sure wouldn't worry about it, unless the oil was still clear from a recent oil change. If it was about due for an oil change, then that sounds pretty good.

Dan

Well it sure hasn't exploded yet. It runs very smooth, oil pressure is

38-42 at idle and 50+ cruising. I haven't heard the faint knock since this first time. I bought an auto stethoscope, parked it on ramps last night and crawled underneath it this morning. It was in the 20's and I didn't hear anything other than a nice whurrr. I probed everywhere underneath. Topside sounded good also.

J Kennedy

JK, Hopefully the grit was a non sequitur. I'd consider changing the oil in a short span and checking for grit again. I'd also treat your engine (spend a few extra bucks) to a real oil filter like a Mobil One. Steve in Michigan

I am going to drain into a clean jug with a magnet taped to the bottom. I don't want to waste 30 bucks worth of Mobil one 15-50 with less than a hundred miles on it. I did use a MB1 filter on the last change. I heard a very faint knock again this morning but I didn't have the stethoscope on hand. I'm hoping it's nothin but I hate having doubts. If it's a wrist pin or bearing can it be repaired from the bottom? The rig only has 29K and runs sweet, I think a complete rebuild would be a waste. Thanks for the reply.

J Kennedy

If it is a bearing then the crank really, really needs to go to a machine shop for a check-up. It can be replaced from the bottom though. Plastigage is a good idea, because the machine shop won't be able to check your bearing bores, which will still be in the engine. If the plastigage results are not good, then you open up a whole 'nother can of worms. Usually, this does not happen, but check anyway.

If it is a wrist pin, then the only way to get to it is with the head and oil pan off. In that case, anticipate piston damage, need for ring replacement, etc.

With a "faint knock" maybe it is piston slap that goes away when the engine is warm, imagination, or gremlins. Hope is a good thing to have, but too much is probably bad too.

Earle

I heard that a main bearing going out would be pretty loud, increasing with temperature and a loss of oil pressure. This knock is barely audible but definitely there.I can't hear it with the hood up, only sitting in the cab with the doors shut. I have only heard it twice, both times at a cold start up. It does go away after a minute or so. As far as the grit goes what could it be? They are very small, black and magnetic. I guess I will know more when I drain it. Thanks for the reply.

J Kennedy

There is always a little metal in the bottom of an engine or gear case. A magnetic drain plug will make it more noticeable because it concentrates it in one small place. That's why there is a fine screen over the oil pump pick up tube (it protects the gears that actually pump the oil). I really think you're worrying over nothing. If you don't hear bearing or piston slap, don't worry.

Let me repeat, that's common. As long as it stops as the engine warms, don't worry. I've had it, and both engines went over 150,000 miles farther before they needed an overhaul. And synthetic oil is usually thinner than petroleum-based oil, and can such noises (and oil consumption) more noticeable.

Dan

Thanks Dan, I am a bit of a worry wart.....Happy Holidays