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D6N Water in the fuel

Pushing forward ยท 2026-03-03 11:08

D6n ALY02368 will get water in the fuel when it sits and idles. The filters have been replaced and the tank drained. Will burn off after a few minutes. What is the cause of this? the cups or o-rings on the injectors?

Replies10
  1. #1Simon C2026-03-03 11:19

    You are getting water in the fuel filter or water in the exhaust on start up or at idle. I am guessing you are talking about on top of the piston. If it is a precumbustion engine then the seals do burn out if lots of hours or overheated. Could be cracked head also or blown head gasket if pushing into the radiator. Need more information. How many hours and is it precumbustion? Simon C

  2. #2Pushing forward2026-03-03 13:54

    There is no water in the filters. Only happens after idling. Has almost 14000 hours. A couple of years ago it was the opposite, fuel was getting into the coolant. I replaced the cups and o-rings and it stopped. Engine is a 3126.

  3. #3Simon C2026-03-03 14:54

    A bore scope might be the solution to find out where it is leaking. You have mega hours for a unit like that if it was never overhauled to new condition, so don't be surprised if you are into a bigger one. Maybe someone else will suggest something simpler, wait and see. Simon C

  4. #4Pushing forward2026-03-03 21:28

    Thank you Simon. Didn't really know where to start the process of elimination.

  5. #5Nige2026-03-03 22:22

    Seconded. If the engine has never been overhauled before then maybe now is the time.

  6. #6Pushing forward2026-03-04 08:47

    How much would an overhaul cost?

  7. #7Welder Dave2026-03-05 01:23

    It used to be around $2000 a cylinder but everything has gone up like crazy. It could be higher depending on what all is needed done. That doesn't include a turbo or injection pump work.

  8. #8Simon C2026-03-05 09:50

    6 injectors for a C15 would be close to or more than $10000. Not sure what motor he has but engines in Canada are $40K - $100K or more depending on the model. Just a Skidsteer common rail pump is close to $10000 Canadian. Equipment is big bucks to fix now a days. That is why lots of it goes to the auction house. Not everything at the auction is junk, but every piece of junk is at the auction.!!! LOL Simon C

  9. #9Nige2026-03-05 10:17

    Engine is a 3126. Should be cheaper to overhaul than a C15 but could turn into a money pit for a variety of reasons.

  10. #10Pushing forward2026-03-05 23:20

    Thank you for some numbers to work with.