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Komatsu pc18mr bad blow by

hvguy · 2020-06-12 01:34

Picked up a unit for cheap, didn't run, got the fuel system bled and it barely ran. All 3 injectors were loose, got them tight, apparently it's been sitting a while. Barely has any power,enough blow-by to force oil out of the pcv. The engine is a 3d67e Kubota. BUT I can't find anything on that engine. Similar models use a d902.... Are these the same engine? Pumps even look the same. Tried running it to hopefully get the piston rings to un-stick but it ended up overheating. My guess is the thermostat is stuck. What's your opinion. A d902 is affordable, but I wonder if it'll fit

Replies13
  1. #102SILVER2020-06-12 18:07

    We have done this exact thing. We picked up an almost dead pc18 mr cheap and swapped in a d902 from a grasshopper mower I picked up for $300. It works great, we use it for pot-holeing existing utilities before we start a job.

  2. #2hvguy2020-06-12 18:10

    Was it a drop in replacement? Dang that would be super easy!

  3. #302SILVER2020-06-12 18:16

    Yes, all bracketry, and engine components bolted right up including pump coupler. Only issue is the oil dipstick ended up on the wrong side(probably changeable). It runs great and is rated slightly higher in HP from the mower configuration.

  4. #4hvguy2020-06-12 18:24

    That's exactly what I wanted to hear for the 2k I paid for it, another 3k would be reasonable. Thanks again!

  5. #502SILVER2020-06-12 19:44

    No problem, I will try to get pictures of it for you tomorrow

  6. #6Cburt2020-06-12 21:32

    Had the same machine and did that exact engine swap at 3200 hrs. Direct swap only difference was oil pan and accessories. Unbolted everything pulled engine and swapped parts. Not bad to do. Less than a day job.

  7. #7hvguy2020-06-12 22:10

    Sounds easy enough. Finding a 902 is appearing to be a ball ache, found a d722 (which is what this engine appears to be) that came out of a heavy truck ac system. They're asking 950, and it's local. May just go with the same old unit. Wonder why these engines only last 2500hrs

  8. #8hvguy2020-06-14 01:37

    Found a d722, basically the same unit. Paid 700, it's an old Apu air conditioning unit for a semi truck. Had 125 hours on it She been sitting for a while but cranked up no problem.

  9. #9hvguy2020-08-12 21:01

    Wow. Where do I even start. I managed to hookup the output from the alternator to ground, the fuel filter leaked and the high speed travel sometime works lol Got everything sorted and the engine works.... But the thermostat housing on the donor engine was different. And there was NO easy way to swap it without removing the head... So I bought a new head gasket and swapped the old head onto the donor engine. So far so good. New thermostat, oil, filter, fuel, lift pump "even tho I figured out the fuse was blown for the pump lol" Now it's leaking oil from the valve cover "ordered a new gasket" and at low rpm it makes a little knock, at high rpm it misfires. My guess is the old injectors need swapped. That's what I'll try first.

  10. #10Anny Brown2020-08-18 22:31

    you can get the complete manual for more details download it

  11. #11hvguy2020-08-18 22:32

    I ended up buying it online, if anybody needs it let me know

  12. #12jmmybuckles2024-03-23 21:50

    Where did you buy the manual from? I'm looking to replace a fuel pump.

  13. #13hvguy2024-03-25 12:27

    I don't remember. I just googled it. And if you're replacing the lift pump, it's just mounted on the side of the machine. 2 wires and 2 hoses. Easy.