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C9 Bent Push Rod???!!!!

stevenatkinson ยท 2015-10-14 12:06

Gents Can any one help me. Our 2009 336d started making a fluttering/missfire yesterday as if she needed a fuel filter while unloading some trailers in the yard, I told the driver to keep using it until he was done and then I would take a look. Just as he was about to park up it started to make a loud popping noise so he shut it down immediately, this morning we pulled the rocker cover to investigate and while checking the valve gear discovered a stuck push rod, so we pulled it and it is bent with a score on it. Any ideas what the cause could be?

Replies6
  1. #1Nige2015-10-14 13:12

    Check the tightness of the rocker shaft bolts, the camshaft lobe condition and the valve that the pushrod operates to see if it's sticking. You might just find a bent valve.

  2. #2stevenatkinson2015-10-14 13:34

    Thanks Nige I will look through your suggestions. How can I check the cam shaft lobe I couldn't see an inspection plate on the engine? Do you know the torque on the rocker shaft bolts ? Thanks Steve

  3. #3Nige2015-10-14 13:56

    74 +/- 15ft.lb. The valve lifters hook out from the top. It needs a hook to get down there to persuade the lifter out of its hole. After that it's shine a light down the hole while you bar the engine over.

  4. #4kshansen2015-10-14 14:37

    Here is a drawing of the valve operating system. The item #1 is a clip that's job is to keep the lifter pointed in the right direction in relation to the cam. Reaching down from the top with a hook, maybe a piece of coat hanger you should be able to pull the lifters out of the bore in the block. Don't want to jinks you but when the 3406 in the 980G at the quarry bent a push rod twice found the problem was this #1 spring clip had failed. This let the lifter rotate in the block. That is not a good thing for the camshaft or the block. We were lucky as this was a fairly recent rebuilt engine by the local Cat dealer and they ate the bill for the reman short block. I believe it is considered standard practice to replace not reuse these clips. At least that was the case years back when we were doing our own engine work at the shop.

  5. #5Nige2015-10-14 14:40

    Indeed it is .........

  6. #6stevenatkinson2015-10-14 15:48

    Thanks for this guys, il check the things Nige suggested if I eliminate them I guess my only option will be to remove the motor as she will need a big strip down to check the cam shaft as it doesn't look like it can be pulled while still in the excavator