Hi All,
I had to pull my oil pan to change my leaky oil pan gasket which was hard as rock, and braze up an annoying pin hole leak on the pan, and in the pan, there was a big glop of old sludge that probably never drained properly, and survived a few oil changes.
Trapped in that sludge was quite a bit of metal fragments. The drain plug magnet had the normal amount of magnetic sludge, but none of this other stuff was stuck to it (even though the metal in the photos is ferrous).
I suppose the question is, how much metal have you all seen when you drop the oil pan, and at what point do you begin to worry?
Hello,
Given the pan gasket was hard the pan's not been off for a long time. That kind of metal debris is not normal but it's hard to tell where it came from and how long it has been there. There is nothing you can do to resolve the issue at this point.
Clean the pan totally, put in new oil, change the filter, drive it for a few hundred miles then pull the pan and see what is there. Hopefully, it will be clean and no debris, even fine particles. If so, then I'd not worry about it but might do a change after a couple thousand just to make sure it was a one time problem.
Ifg more of that stuff shows up, you have a major internal engine problem. Others here can advise how to proceed down that path.
Oil sample after 100 miles with oil change. Or if you still have the old oil, draw a sample.
The engine runs well and doesn't show any signs of being unhealthy in any way, so I 'guess' its not ring or cylinder wall material. One of the samples looks mixed with brass or some yellow metal.
Looks like a thrust bearing material and a drive coupling material on the rear for the compressor, alternator or power steering ,the thrust bearing take a beating on engines with clutches and manual transmission now is the time to replace those with the pan off and roll all new bearing rods and mains both ,cheap insurance for you a nasty job but worth it ? how many psi of oil pressure do you have
Quote from: luvrbus on November 02, 2022, 07:10:55 PM
Looks like a thrust bearing material and a drive coupling material on the rear for the compressor, alternator or power steering ,the thrust bearing take a beating on engines with clutches and manual transmission now is the time to replace those with the pan off and roll all new bearing rods and mains both ,cheap insurance for you a nasty job but worth it ? how many psi of oil pressure do you have
Rolling in new bearings would be a no brainer if it is a thrust bearing check the crank,cap and block for damage too. Old debris from a previous issue is not likely unless the pan didn't get cleaned out.
Quote from: tr206 on November 03, 2022, 04:48:44 AM
Rolling in new bearings would be a no brainer if it is a thrust bearing check the crank,cap and block for damage too. Old debris from a previous issue is not likely unless the pan didn't get cleaned out.
That magnetic drain plug had next to no debris on it. Just the normal magnetic slime, and not much of it. This make me think that because this metal was held down in a layer of old sludge, the metal was something that happened prior to the rebuild? That's just a guess. It looks like the old pan didnt get cleaned.
I have good oil pressure, and it comes right up.
I would pull the oil pickup and check a couple of main bearing and rod bearings if they are good, it only cost you a little time, I doubt it is from a previous failure,sludge in a Detroit oil pan is caused by low operating temperatures, or crappy oil, cut the bottom from the oil filter and see what you have inside it
Quote from: luvrbus on November 03, 2022, 06:44:40 AM
I would pull the oil pickup and check a couple of main bearing and rod bearings if they are good, it only cost you a little time, I doubt it is from a previous failure,sludge in a Detroit oil pan is caused by low operating temperatures
Do those rod caps pop off when you remove the two nuts? Or do you need some kind of puller? Do you know the torque specs to put the two nuts back on?
Quote from: brianzero on November 03, 2022, 06:48:16 AM
Do those rod caps pop off when you remove the two nuts? Or do you need some kind of puller? Do you know the torque specs to put the two nuts back on?
Just tap the side they come off easy,rod bearings torque at 65 to 70 ft lbs the mains at 230 to 240 ft lbs pull the rear main and check it too it will have a set of thrust (washers) bearings on it
Quote from: luvrbus on November 03, 2022, 07:05:14 AM
Just tap the side they come off easy,rod bearings torque at 65 to 70 ft lbs the mains at 230 to 240 ft lbs pull the rear main and check it too it will have a set of thrust (washers) bearings on it
Good, thanks for that torque spec. What do you think about this main cap removal and bearing inspection video? I suspect this is what I will be working with:
https://www.youtube.com/watch?v=jHeO1h3U4GE
Quote from: brianzero on November 03, 2022, 07:18:25 AM
Good, thanks for that torque spec. What do you think about this main cap removal and bearing inspection video? I suspect this is what I will be working with:
https://www.youtube.com/watch?v=jHeO1h3U4GE
A little tip if you roll new main bearing in ,loosen all the main caps remove and replace 1 at a time with the caps lose then the main bearings roll in easy then go back and torque the mains
Why not just throw in new bearings if I'm in there?
Quote from: brianzero on November 03, 2022, 08:02:05 AM
Why not just throw in new bearings if I'm in there?
I would myself,but sometimes the bearing are ok and people use the old ones, bearings are cheap any sign of wear I replace all the bearings
The others have the experience and know how but I have some common sense. If you want to resolve the stated concern you posted and state the engine runs good, oil pressure is good, etc. then you could start changing parts but I don't see how that resolves your conern.
If the bits are stuck in the sluge and not stuck on the magnet then it is likely from some previous incident. Clean the pan, change the oil and filters and run it for a bit. Check the magnetic plug and if clean, you are all good. KISS
The problem is Don he has no history on the engine or didn't post it anyways, he has something going on 92 the series are tough on bearing they use the same bearing as the smaller *v71 and Detroit recommends replacing the bearing when they wear.He says he has good oil psi but what is it ? for 200 bucks worth of bearings, he is good for another 100 thousand miles. The old 2 strokes will run when they need attention that is a problem and people don't give the TLC they need, Common sense and being cheap are not the same IMO
Bus Grease Monkey has a couple videos about replacing the bearings on 8V92 back when he was still on the road.
https://www.youtube.com/watch?v=YhwAIekFleQ&t=9s (https://www.youtube.com/watch?v=YhwAIekFleQ&t=9s)
https://www.youtube.com/watch?v=2aC09lw7cu0 (https://www.youtube.com/watch?v=2aC09lw7cu0)
Remember, if you dig into it to check the bearings, check for the undersize markings.
My old Fishbowl 6V71 with 2 speed Allison had issues once. We were getting ready for about a 500 mile trip so I decided to change my tranny fluid. The transmission dropped a bunch of large steel pieces, some about 1/2" across. I could have filled a coffee cup half way. Once I'm geared up for a trip, it takes a lot for me to change my mind. I cleaned out what I could, put new fluid in and went on the trip anyway. The bus ran perfect, but I did end up installing a rebuilt unit the next year that was once owned by the local city shop and was eventually sold to a transmission shop. No problems after that. The point being that it is amazing how that kind of thing can be in there and the bus still runs well. I would follow the advice to change the oil again later and see if anything new shows up (and maybe pull a sample of the old and have it tested too).
Thanks for all your knowledge and collective experience and advice. This will keep these old detroits alive.
Im going to pull the main crank bearing caps and see what kind of shape they're in. If they're thrashed, Ill assume they're all thrashed, then Ill order a set of bearings.
Quote from: brianzero on November 03, 2022, 01:13:41 PM
Thanks for all your knowledge and collective experience and advice. This will keep these old detroits alive.
Im going to pull the main crank bearing caps and see what kind of shape they're in. If they're thrashed, Ill assume they're all thrashed, then Ill order a set of bearings.
If you have the Detroit engine manual it will show pictures of bearings usable and non-useable and give you the allowable specs ,the rear main will show the most wear since it is the last in the pecking order to get the oil flow
Quote from: luvrbus on November 03, 2022, 01:21:13 PM
If you have the Detroit engine manual it will show pictures of bearings usable and non-useable and give you the allowable specs ,the rear main will show the most wear since it is the last in the pecking order to get the oil flow
I do have the manual. Im going too start studying the parts involved.
Hey luvrbus, would you use new bolts for the bearing caps?
Not necessary,, but pay attention to the torque specs..>>>Dan
Quote from: chessie4905 on November 03, 2022, 11:04:17 AM
Remember, if you dig into it to check the bearings, check for the undersize markings.
Like chessie4905 said if you do change bearings look on the back of the bearing to find out what size they are (before you order them) check 1 rod and 1 main they maybe different sizes.
When we did our in-frame rebuild we plastic-gaged all the rods and mains before & after total bearing replacement it really told the overall condition of the rod & crankshaft journals. The thrust bearing was almost toast and rolling the new bearings in was a breeze. All the journals were 10 thousandths under. Ordering parts was a bitch until I learned it was a Grey Marine block - not a Detroit Diesel (with Clifford's help) as there were no Detroit stampings anywhere. At 17,000 miles on the rebuild it runs awesome - great oil pressure and consumes/leaks three quarts of oil in 5000 miles. Do whatever you personally need for peace of mind. :^
Here we are with the first bearing cap off (front most cap). What does everyone think of this condition, I think theyre very good, minus some dirt scratches:
Should I even bother to pull the upper bearing when it looks like this??
The second bearing looked even better than this one. There is clearly no issues in this department. Im going to take a look that that rear main bearing and thrust bearing.
Those look good the wear is mostly on the lower cap bearing,you should pull the rear to check your thrust washers
Make damn sure you replace each bearing cap as it came off that throw,, don't attempt to install it after turning it around,, the bores are ground as a set and only fit properly one way..>>>Dan
I see piece of mind there w/o replacing anything yet. Looking forward to seeing the condition of the thrust bearing.
Quote from: Utahclaimjumper on November 07, 2022, 03:23:00 PM
Make damn sure you replace each bearing cap as it came off that throw,, don't attempt to install it after turning it around,, the bores are ground as a set and only fit properly one way..>>>Dan
Yes, 100% correct. Everything gets installed in the correct direction. I have numbers on my caps pointing in the right way.
After installing and torquing rods, try moving it back and fourth. Only a few thousandths, but it should move.
I had a look at those thrust bearings, and they looked brand new. They still have the casting marks on them! I didnt even bother taking pictures of them.
Quote from: brianzero on November 12, 2022, 03:44:18 PM
I had a look at those thrust bearings, and they looked brand new. They still have the casting marks on them! I didnt even bother taking pictures of them.
Now you know someone has been into the engine recently,still no good shop is going to leave that junk in your oil pan maybe rags lol one on F/B a oil can was left inside it
Quote from: luvrbus on November 12, 2022, 04:01:49 PM
Now you know someone has been into the engine recently,still no good shop is going to leave that junk in your oil pan maybe rags lol one on F/B a oil can was left inside it
Could those metal flakes be from the starter ring gear grinding, or timing gears meshing??
It could have come from the gear train,the idler gear has a bearing and a hold down cover,the cams have locking plates on the auxiliary drives, measure the thickness of a piece of metal and I can tell you if one has broken which they do, the 50D alternator can give you some extra pieces too,so can the air compressor. As mentioned, change the oil and filter and have the oil tested in a few thousand miles, the oil pan is not that hard to remove either to check for more chunks of metal later