oil analysis results: not good

[lostagain]

This is for the 6V92TA in my MC5C I got last Spring.

About 200 000 km since new in '93, according to PO.

Drained the oil when I put it away for the winter a couple weeks ago, and sent a sample to DD lab. About 20 000 km on it, again according to PO who said it had about 5 000 when he sold it to me.

Iron is hi at 119

Tin hi at 34

Silicon hi at 28

Those were circled by the lab tech as being hi.

So I will put in new crank and rod bearings this winter.

The engine runs well and strong. It doesn't burn any appreciable amount of oil. Doesn't smoke other than when mashing the pedal. Although I did notice that it doesn't start as easily as it should in cool weather.

What are you guy's suggestions and ideas and advice?

The silicon content I think is from the air filter I removed earlier this summer. I have replaced it with an ECO, and I am pretty sure there are no leaks, although I will double check.

The good news is, there is no fuel or water or coolant in the oil.

JC

[eddiepotts]

I think I would run your oil change another time and have it checked again. If you are not having any problems or noises your last oil run may have been longer than you think. I know in my world at the refinery we use risk management on fixing things and sometimes you have to let it show a problem to know what to fix. you can rebuild it now or wait to find out that it is just really old oil. How was your acid content. If it was high that will tell you it has been running for awhile.

[lostagain]

I don't see acid anywhere.

Here is a copy:

[luvrbus]

Jc, the high iron is probably coming from the compressor drive or another drive if you have the gear driven alternator that would be the first place I checked when they start to wear the iron will go up.
The tin will most likely be a thrust bearing on the main the 740 transmissions are tough on those and the silica will be a air cleaner system problem at 100,000 + miles you are due a bearing change  



good luck

[lostagain]

Thanks, I can do the bearings that's easy.

The alternator is belt driven. The compressor is gear driven. What do I look for on the drive? Should I remove the comp., then look for what? I'll look at the service manual to see what it looks like in there.

Thanks,

JC

[luvrbus]

JC, the compressor will also make the iron content go up when they start to go bad plenty of spots to check for iron on a 2 stroke lol


good luck

[robertglines1]

was sample taken mid stream? if you take it first or last sometimes readings will be extreme..bearings are not hard to roll in ;the torque wrench is hard at that setting.only took me about 3hrs to do rods and mains on my 8v92. If I can do it anyone can.   Bob ps  torque wrench was hard pull for old man me  270# or what ever book said..have only shallow pit about 3 ft deep.

[lostagain]

I took it at the beginning. So yea, mid stream could've been better. Although it was shortly after shut down.

What do you mean by "the torque wrench is hard at that setting"? Are you talking about torquing the bottom bearing caps?

I've done bearings before when I overhauled my 4-71 on my other bus, so doing them on this one doesn't bother me, in fact I will replace them for sure.

I was just looking at my engine and the power steering pump and the air compressor look like they are direct (gear) driven at the back of the engine. Awkward area to work on... I hope I don't have to pull the engine...

JC

[5B Steve]

     Lostagain,


  I'm in that business, 146 ppm of Iron is where you want to keep an eye on.  Silicon, If you use the Lucas oil stabilizer it will show high results.

Also, have you had any head gasget work done?  Gasget sealer, will also show up.  Several oil changes without the use of the formentioned product

will change the analysis.  Good luck!


Steve 5B.......

[lostagain]

Thank you Steve5B, I'll put in new bearings anyway, and look at the comp. and power steering drive. I never used Lucas add., but who knows what the PO did. I haven't done any gasket work either... I'll see what the analysis looks like next fall after another 20 000 km on new bearings.

JC

[pvcces]

JC, from the low soot reading and the warning that the wear is severe, I would be really diligent about finding any air induction leaks. The low soot says that you don't have as many miles on the oil as you think that you do.

Some of these tests allow up to 6% soot before requiring an oil change.

Good luck.

Tom Caffrey

[gus]

Oil analyses are quirky at best, there are so many variables.

In any case, one reading is not enough to give much of a picture. You need at least three to make any sense of it.