Page 1 of 5 123 ... LastLast
Results 1 to 10 of 46

Thread: road grader #12 black smoke low power

  1. #1
    Join Date
    Oct 2017
    Posts
    10

    Default road grader #12 black smoke low power

    Hi. I'm a new member and hope that the experience on this forum can help me. A neighbor and I have a mid 1950's road grader #12 with a turbo engine. It is blowing HUGE amounts of black smoke when under any load at all and has very low power. This problem started fairly abruptly after sitting unused over a winter. At idle or very low load (like driving on the level in 1st gear), it feels and sounds normal, but add even a modest load (like driving uphill in 2nd gear), there is so much black smoke that it completely engulfs the machine so badly that from 50 feet away you can't even see it. Presumably too little air? I haven't completely removed the air cleaner, but removing the oil pan on the bottom of the air cleaner to give easier air flow made no difference. I suspect the turbo as it is sounding a bit more shrill than the high pitch whine I am used to. I tried measuring the boost pressure, and at no load and fast idle, I get barely 1 PSI. At normal to high operating speed, but still no load, it will go up to 2 to 3 PSI with a rapidly fluxuating needle. I did not try to measure it under load, but I would assume that under load, the higher exhaust volume would result in more boost. Problem is it lacks the power to apply much load and when loaded it smokes so bad that I can't breathe anywhere near it. It is really that bad. Are these reasonable boost pressures under these conditions? If I can manage to get some load on it, what pressure should I expect to see? The fuel is a bit old, but it looks and smells normal, and as I said before, everything seems fine at low load, so I'm inclined to not suspect the fuel. Any advice will be appreciated. Our homes are fairly remote, and if we have a heavy snow winter, we won't be able to keep our road open without this machine.
    Thanks,
    Bob

  2. #2
    Join Date
    Sep 2009
    Location
    Asotin, Wa
    Posts
    1,204

    Default

    Sounds like itís getting choked for air to me. Check all the inlet pipes for obstruction like a mud dauber nest etc. then verify the turbo impeller is really turning and not bound up. Your fluctuations on the gauge might be interpreted as a valve sticking. Obviously itís getting plenty of fuel so Iíd rule that out. Might also take the muffler off, if it has one, that would rule out exhaust restrictions.

    Let us know how you come out.

    BP.
    Two Ton, Diesel 40, No.11 AutoPatrol , 4G D4, 9U D6, 44A D6B, 17R D6C, 9G D7, 7M D7

  3. #3
    Join Date
    Nov 2006
    Location
    Corralitos, Ca.
    Posts
    13,183

    Default

    Try running without the air cleaner as a test. Filter media may be all plugged up.
    About 7 to 7.5 psi boost expected.
    It is not recommended to use steam to clean the media.
    Last edited by Old Magnet; 10-31-2017 at 12:19 AM.

  4. #4
    Join Date
    Nov 2006
    Location
    Faunsdale, AL USA
    Posts
    3,212

    Default

    Removing the oil cup will not make much difference in the restriction caused by the air cleaner. The screens that can be removed and the "steel wool" packing above them may be packed solid with dust and oil that has turned into asphalt.

    The recommended cleaning procedure is to immerse the whole canister in solvent like mineral spirits, kerosene or diesel and plumb an air line to bubble up under it so there is agitation, turn on the bubbler and let it go for some hours. Steam cleaning and other water washing procedures can leave any remaining dust and oil not removed in an even more impervious state than before you started. So if you go that route, get it CLEAN!
    D2-5J's, D6-9U's, D318 and D333 power units, 12E-99E grader, 922B & 944A wheel loaders, D330C generator set, DW20 water tanker and a bunch of Jersey cows to take care of in my spare time

  5. #5
    Join Date
    Jun 2007
    Location
    Colorado West
    Posts
    1,006

    Default

    Look at the turbo impeller with the air cleaner pipe off, see if it's spinning. If the problem started abruptly after it sat, the turbo may be stuck, possibly from rust and carbon coming loose in the exhaust. . . if the turbo doesn't sound right, there's your sign.

  6. #6
    Join Date
    Nov 2006
    Location
    Faunsdale, AL USA
    Posts
    3,212

    Default

    Someone would have to have recalibrated the governor or changed pumps, nozzles etc to have a 1950's #12grader that required turbo boost to NOT smoke. The CAT turbos of that era were used only to "normalize" the engine performance at high altitudes

    The 12E grader with the D333 introduced in1960 still did not use the turbo boost to increase horsepower. Prior to that there were D318 (G?) turbocharged engines I think were used in #14 graders that utilized the turbo along with higher fuel rate for increased horsepower as well as industrial power units of the same era similarly equipped, so it's possible the engine might be a transplant.

    One thing nobody has asked is if it has excessive blowby coming out of the crankcase breather. Especially if that has a "huffing" quality to it, I would suspect one or more damaged pistons possibly resulting from stuck rings.
    Last edited by ccjersey; 10-31-2017 at 09:12 AM.
    D2-5J's, D6-9U's, D318 and D333 power units, 12E-99E grader, 922B & 944A wheel loaders, D330C generator set, DW20 water tanker and a bunch of Jersey cows to take care of in my spare time

  7. #7
    Join Date
    Oct 2017
    Posts
    10

    Default

    Thanks everyone for the suggestions. I will follow up on those and get back with the results.

    ccjersey, I can't find an engine model number, just the serial number #8T19245. Is that enough to ID the engine? As far as I know it is the original engine, and it exactly matches the pictures in the manual. We bought it from the County, and a friend who worked at the county shop for many years said that they had it rebuilt, but doesn't recall it ever being replaced. they also used to have another one supposedly like this one except it didn't have the turbo. We are at 3000 ft, so maybe they ordered this one with the turbo for that reason, as you suggest.

    The air pipes to and from the turbo are several cast sections. Are they just a friction fit between sections or is there some kind of sealer? Any particular cautions in separating them?

    Thanks again. I will report back.
    Bob

  8. #8
    Join Date
    Nov 2006
    Location
    Corralitos, Ca.
    Posts
    13,183

    Default

    The air pipe joints are either gasketed or use o-ring type internal seals.

  9. #9
    Join Date
    Oct 2017
    Posts
    10

    Default

    OK, here is an update.
    Removed the air cleaner. No improvement.
    Checked crankcase breather. No noticeable discharge.
    Was going to remove muffler, but discovered there is none. Just an empty exhaust stack, so no blockage there.

    So now it is looking more like maybe the turbo.
    I understand how turbos work, but have no experience with them and have never seen inside one. I do believe that it is turning because I can hear it, but it's a harsher sound than the high pitch whine that I remember. I had hoped to remove the air pipe into the turbo to see if it was turning easily, but was unable to get it off. I also have been unable to remove the exhaust stack from the turbo, so I am not yet able to determine if the turbo is spinning easily and not dragging. Instead, I removed the air pipe between the turbo and intake manifold. What a bear! Still blew black smoke. I'm a bit confused by what I see inside the air output side of the turbo. Should I be able to see the turbo vanes? All I see are two metal disks about roughly 7" diameter with about 1/16" space between them. Seems like a tiny space for the air coming off the impeller, but I see nowhere else for the air output to be coming from.

    So, what I know now is that even with the air side of the turbo out of the equation, it still smokes. Question: if the turbo is stuck, or more likely dragging, would that create significant back pressure? If so, am I correct in thinking that with sufficient back pressure the cylinders wouldn't evacuate all the exhaust and therefore wouldn't be able to take in enough air? Looks like I am going to have to get access to one end or the other of the turbo to see if it is turning freely.

    Bob

  10. #10
    Join Date
    Nov 2006
    Location
    Faunsdale, AL USA
    Posts
    3,212

    Default

    I am surprised that it still smokes with no restriction to the intake, but you did say it smoked badly even when it had 1 or 2 psi boost, so I guess that is to be expected.

    The grader serial number on the engine tag does indicate it is original to the machine.....though it could have had the tag moved if the engine were ever replaced. But you have a history that it is original so I would go with that. 8T19245 was manufactured in 1956

    The #12 graders manufactured from 1948 to 1959 all used the 4.5" bore 6 cylinder D318 engine with the governor set at a higher rpm and probably increased rack setting compared to the D6 tractors I am used to dealing with. It is likely that the fuel delivery of that engine is increased beyond the normal non-turbo grader and the turbo is required to make it perform.

    The only other thing I can think of is if the engine was trying to lock up and spin a bearing or the clutch was somehow dragging, the governor might go to full fuel attempting to bring the rpm up and cause it to smoke badly.
    D2-5J's, D6-9U's, D318 and D333 power units, 12E-99E grader, 922B & 944A wheel loaders, D330C generator set, DW20 water tanker and a bunch of Jersey cows to take care of in my spare time

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •