Broken Piston Ring?

[Bobbie Martin]

Well, it seems like I have a problem with the Suburban. I did an oil analysis a while back and the results are not good. Its a 1995 with 181,000 miles. We are the original owner, so I know the complete history of the engine. It never overheated, really no internal problems at all. Its been regularly serviced with Rotella or quality diesel oil since new.

The oil report says: "Both chrome and iron were well above average in the latest sample from your Suburban. Chrome comes from the rings and at this level it may show that one is cracked. Iron is from a steel part and is likely coming from the cylinders. This is something that should be addressed sooner than later, so you may want to consider having a mechanic take a look at your engine. No harmful contaminants were found, though soot was high and this is probably related to wear."

Elements were as follows, first number is the latest, number in parentheses were the previous readings.
Chromium 13 (1)
Iron 151 (34-40)
Molybdenum 13 (1-2)
Nickel 4 (0-1)
Lead 13 (5-7)
Tin 3 (0-1)

It seems to run OK, smokes a little at startup, but no odd noises. I can't think of what else may cause this (other than a broken ring) but driving it you would never know there is a problem.

At this point, I'm not sure what I'm going to do, any advice would be appreciated. The Sub is now our spare car, we have other cars we drive to work, but it sure is handy to have the Sub when we need it.

Thanks, Bobbie

[Robyn]

I would keep the oil changed and just run the beast.
At 180K + its going to give what ever it has left.
Dump a can of STP in the little creature to slick it up some too.
I run STP in all my 6.5's. always have.

You can opt to yank the engine and pull it down but I would run the last of the goody out of it.

Those numbers are just what I would expect with close to 200K.
The bearings are wearing some now and shedding a little material as well as other parts.

Oil analysis is a good thing but unless you are seeing issues such as loss of oil pressure, excessive oil consumption (smoking) ect I think all it is doing is make you worry.

Run it till it pukes. In the mean time start looking around for a good late model buildable engine to get ready as you can afford, to drop in when the old girl gives up

Best
Robyn

[JohnC]

A broken ring will sometimes make a screeching noise if you turn the engine over by hand. Or, you could do a cylinder leakdown test. Or, you could pull the heads off and look. Or, you could keep driving it until it gets really bad...