Some of you may know that my transmission died, and my engine is getting pretty old. I ran across a bus with a supposedly solid engine and transmission that I am thinking of buying to be a donor for my bus.
Stats are: Detroit Diesel 6V92 + Alison HT740
The engine was supposedly rebuilt about 60k miles ago, though it's been around 10 years. The rebuild was actually done by Detroit, which is a good sign.
The bus is far from me, so I took it to a mechanic to check it out. There are no two-stroke diesel mechanics in the area, so I took it to a truck shop. It starts up fine when it's cold and isn't really dripping any oil or blowing smoke. That's a good sign. Drives fine, too. I had them pull the transmission oil and engine oil, and this is where I get slightly worried.
The lab results came back - the transmission oil is fine, but the engine oil had elevated metals, specifically 100ppm of Iron (Fe) and 19ppm of Tin, and the diagnosis says: "Wear metal(s) high-indicating possible cylinder wear and piston scuffing." Everything else reads normal, and it's marked as "Caution" as opposed to "Sever" or "Abnormal" or "Normal"
So.. how freaked out should I be about that?
The oil was supposedly changed maybe 10k miles ago, but who knows - the mileage on the bus isn't completely clear, and there's no way to be sure about these kinds of things...
Any thoughts on how much of a danger sign 100ppm of Iron is on an engine that seems fine otherwise and was supposedly rebuilt 60k miles ago?
Going by memory only, I believe above 10 for tin is the beginning warning level, and above 300 for iron, but that was for 4 cycle diesel. If those were the only two items out of bounds on the report, that is not too bad for an engine that has 10,000 miles on the oil and may have been sitting for a while. Any rust in the system would add to the count. If the oil pressure is good, and there was no long lasting smoking going on at startup, and no pronounced oil dripping, you are ahead of the curve. Price becomes a deciding factor. The main thing is absence of overheating signs or antifreeze in the oil. New main bearings could be spun in at not too great a cost, if need be.
pull the air filter and bounce it on the pavement...if it rains sand...well .. it's probably been dusted..
call this guy
he will tell you what the deal is
http://www.infielddiesel.com/service.html (http://www.infielddiesel.com/service.html)
chris
mci5c
The warning limit on a 6v92 for iron is 150 PPM FeMax go for it, 100 ppm is not bad for 60,000 mile 6v92 that could be from the gear train normal wear if any gear was replace Glycol is the killer,? what was the copper
Quote from: luvrbus on April 06, 2017, 07:33:48 PM... Glycol is the killer,? what was the copper
Yes, moderate levels of iron are a normal break-in component in oil. Silica indicates a bad air filter or an induction air leak. Glycol (antifreeze) in the oil is a BIG danger sign, it very likely means that the engine was overheated to the point that gaskets don't seal (i.e. damage to the block or heads); plus, oil with antifreeze in it will kill bearings and rings in just a few miles. Copper and tin are from bearings -- you're going to have *some* copper and tin, esp. in an engine that has oil that was run past the oil change interval, but too much is deadly.
You've already said this engine is showing moderate iron, that's probably not a terrible sign. If the silence on glycol and silica means those numbers are good, that's very positive. The tin is a little high but if the copper is normal, I wouldn't worry about it.
Once you've very carefully looked at the full report and nothing more than what you've noted here is indicated, my guess is that you'd be good to change the oil, run it for 2000 miles and change it again, then do another analysis at the proper interval. If you treat that engine right, you'll probably find that it's OK; about the worst you'd find is you'll have to replace bearings but that's reasonably easy and not a big $$$ shocker on an engine you got a good deal on in the first place.
On the other hand, every used engine is somebody else's hand grenage ...
Quote from: eagle19952 on April 06, 2017, 06:45:30 PM
pull the air filter and bounce it on the pavement...if it rains sand...well .. it's probably been dusted..
Dusted?
Quote from: luvrbus on April 06, 2017, 07:33:48 PM
The warning limit on a 6v92 for iron is 150 PPM FeMax go for it, 100 ppm is not bad for 60,000 mile 6v92 that could be from the gear train normal wear if any gear was replace Glycol is the killer,? what was the copper
Copper was 26.
If the warning is 150 ppm, why was it noted as 'caution'?
Just different levels for different test companies?
The copper is over the warning limit of 25 ppm for 6v92, only bad thing about a oil sample you need 2 so you have a base to go by,I have no idea why they flagged the iron, 150 ppm is the same for a series 60 Detroit
Quote from: daveola on April 07, 2017, 10:09:07 AM
Dusted?
the air filter was deteriorated of past it's useful life.
it could have passed grit into the cylinder causing the scuff.
commonly referred to as dusted
Quote from: luvrbus on April 07, 2017, 12:30:02 PM
The copper is over the warning limit of 25 ppm for 6v92, only bad thing about a oil sample you need 2 so you have a base to go by,I have no idea why they flagged the iron, 150 ppm is the same for a series 60 Detroit
One companies warning is different from another, it would seem. That's why it would be great to know what the ranges are.
What ranges of copper and iron ppm do people think are acceptable?
Usually, (but not always) the normal range of various engine, transmission, radiator, rear end and hydraulic motor contaminants will be listed on the results sheet.
Usually a computer printout but sometimes only hand written. What might work would be to befriend a knowledgeable shop who trades with just a couple of good labs.
They might take a little time and explain it all. Sometimes a gratuity helps. Too many numbers to memorize. These tests today are very comprehensive and very helpful.
Kinda like a human blood test workup. All sorts of numbers we were at one time expected to memorize. Mistakes happened. Nowadays all printed out for us. Yikes!
Quote from: HB of CJ on April 08, 2017, 06:29:52 PM
the normal range of various engine, transmission, radiator, rear end and hydraulic motor containments will be listed on the results sheet.
I know - I was surprised (and disappointed) to not see them.
i would have to question if the sample was even done...
how much did you pay?
who actually drew the sample?
was it a separate sample or part of a batch?
i have sold/serviced a lot of samples....
a single sample not on a scheduled contract was close to a $100.00
$70.00 was the least...
I would say over 1/2 of those people don't even know how to pull a sample ,I saw people do some crazy stuff trying to do a sample
The sample cost something like $60 for each, it was sent to Detroit Diesel and was pulled by the mechanics who are checking the bus out.
Quote from: daveola on April 08, 2017, 08:33:26 PM
The sample cost something like $60 for each, it was sent to Detroit Diesel and was pulled by the mechanics who are checking the bus out.
Labs can only test the samples they have no idea where and how it was taken,I have seen people (mechanics) pour oil from a oil filter into a sample bottle before a big No/No
I don't like the scuffing on the pistons and liners. This would not make a drop in replacement. I would pull the heads and oil pan, and look at the pistons, liners, and all the bearings. Then take it from there. That engine might have been overheated and patched.
--Geoff
Quote from: Geoff on April 09, 2017, 12:38:28 PM
I don't like the scuffing on the pistons and liners. This would not make a drop in replacement. I would pull the heads and oil pan, and look at the pistons, liners, and all the bearings. Then take it from there. That engine might have been overheated and patched.
The bus is up in Oregon, and I'm not sure I can find someone (or spend more money on a bus I haven't bought yet) to do all this.
You are assuming scuffing on pistons/liners because of the 100ppm Fe?
Evidently the sample (for the engine) was taken from the drain plug.
Quote from: daveola on April 10, 2017, 12:51:29 PM
Evidently the sample (for the engine) was taken from the drain plug.
You never pull a sample on the drain stream like the drain plug on the oil pan
Quote from: luvrbus on April 10, 2017, 12:54:26 PM
You never pull a sample on the drain stream like the drain plug on the oil pan
It would be fun to watch though ;D
oil sample tool:(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fwww.lubecontrol.com.au%2Fwp-content%2Fuploads%2FOil-Sample-Pump.bmp&hash=3a6a4b30b91640ea8249d67142b4d5ff50bd81a6)
I quit doing oil samples for the bus a couple of years ago. Too stressful looking at the results. I change the oil regularly, and look for antifreeze and metal shavings when I drain it. I listen to the engine and transmission when I drive. That has served me well for 40 years in all my vehicles and various machinery. Keep it simple...
JC
LOL samples can be stress full,JC just for the hell of it I took a sample from a 8v71 that the oil had been changed 1 time in 15 years, believe it or not it came back with only high levels of silicon.
I could see that with the oil bath filters they are always on the high side .I am guessing because it leaked so much it always had clean oil. I was amazed thinking it would have high levels everything except AIDs.Makes me wonder now about your theory on changing oil at least once a year
Respectfully. Some help here please. Have I been doing it wrong for 55 years? Maybe so. We were taught to let the vehicle come up to normal operating temps then pull the drain plug, let the oil pour out for a few moments or seconds, then get what is called a "clean catch" into the sample bottle. A messy fun job guaranteed to get some laughs. Is there a better way today? Yikes!
Funny that the technique taught for catching a hot oil sample was about the same as catching a medical patient urine sample. Only the patient does his own catching. Sometimes the RN has to do the catching. Yuck! Sometimes a sight to behold for all involved. Prison drug testing. More Yikes!
HB of CJ ex RN. an Old Coot! :) No dog in this.
QuoteWe were taught to let the vehicle come up to normal operating temps then pull the drain plug, let the oil pour out for a few moments or seconds, then get what is called a "clean catch" into the sample bottle.
That is the procedure I know. Even more than a few seconds, ensuring enough time to get all the stuff that may be settled near the plug. My understanding is good fleet managers take samples regularly and do make decisions based on the trending of the samples, like when to put the vehicle up for sale before getting stuck with a big repair.
Most diesel engines of today have a port just just for oil sampling,I was taught to take a sample as Henry described then I was re programed years later to never take one on the drain stream.
I don't know of any major diesel engine dealer that will take samples from the pan plug for the past 25+ years.To answer the question Henry yes there are better methods safer, cleaner and better.
I take oil samples for Garys 12v71's in his boat one would be in a hella of shape looking for a drain plug on the pan with the dry sump 12v71's.
Times are changing for us older guys Henry some of the kits come with special cutters to cut the tubing with now ::) no more razor knifes or scissors.
FWIW I always take 2 samples from the same engine if the 1st sample is over the limits I send the 2nd sample in for comparison labs can screw up
Thank you. Different applications for sure. We used to do oil changes on various yachts sucking the oil out as there was zero room under the pans. As the available skinny young kid I was the sucker who had to wiggle down around and beside the mills to change the oil filter
Also the "clean catch" oil sample was only available during an oil change with the car up on the rack. High school auto shop way back in 1965. Has it been that long ago? We also sent the oil samples to different labs for comparisons. Donated engines were sometimes dusted.
OK. I'll bite. What are the best ways to catch a clean oil sample from a DD 2 stroke block?
Quote from: windtrader on April 11, 2017, 09:48:27 AM
OK. I'll bite. What are the best ways to catch a clean oil sample from a DD 2 stroke block?
Take it through the dip stick tube with the nylon tubing and the vacuum pump or you can remove a oil galley plug and install a sampling port I do through the dip stick tube on most old 2 strokes
Ciff,
Thanks for the tip on installing a sampling port. I've always been concerned with scrapings on the inside of the dipstick tube but didn't see another way of doing it unless I wanted an 'oilbath' which I get everytime I change the oil. on anything :'(
What exactly is the reason to not take a sample from the pan's oil drain soon after shutting down a hot engine? I understood the oil had to be up to temperature, well mixed, and without condensation - is this not how it should be? One reason I installed a Fumoto oil drain valve was to make it easier to draw samples. I understand about preventing contaminants getting in the sample, so I would thoroughly clean the Fumoto before use.
John
The concern is if the plug is on the bottom of the pan then particulate matter that has settled to the bottom of the pan will get pulled into the sample. That is why taking the sample via the dipstick tube allows for the sample to be taken from the top/middle of the pan.
Quote from: windtrader on April 11, 2017, 09:48:27 AM
OK. I'll bite. What are the best ways to catch a clean oil sample from a DD 2 stroke block?
with the sampling device i posted...if the outside of the bottle is dirty...they did it wrong.
I didn't realize how anal some people can get over an oil sample. If there is $#!% in the oil, it will show up in the oil sample, no matter how you carefully obtained it.
--Geoff
Quote from: eagle19952 on April 11, 2017, 05:35:19 PM
with the sampling device i posted...if the outside of the bottle is dirty...they did it wrong.
OK. The image posted was a bit incomplete. It was not clear there is a tube that goes down the stick tube.
It is the unknown **** you don't want in a sample if you pay the price for a oil sample why not do it right.
The labs like Cat the only labs I have toured are spotless if only a hospital was as clean.The labs write the rules for testing to give you the best service and results possible so I follow the procedure they recommend, others can use any procedure they choose JMO