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western iowa,by Denison | So we replaced the lifters and pushrods and it happened again-now take the head off???Its a 4cylinder diesel motor in my 324j wheel loader if that matters? Like feeding cattle with right hand gone |
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n.c.iowa | All of them or just one cylinder? |
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ec. nebr. | If you are bending pushrods, you have a mechanical hit on the valves. Maybe the cam is out of time? Esp. if it is happening on more than 1 cyl. Otherwise could be a bad spring causing coil binding on a single valve. I would say you are ready to grenade this engine. Can't believe it would start even if hitting valves you would think they would get bent and you would have no compression for combustion to occur. |
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| YEP... 'head comes off'. Before you do, check the cam timing just for giggles, especially if all 4 cylinders are getting bent. If just one, probably not necessary. You may have a huge buildup of carbon on the piston tops, valves, or other foreign object causing binding.. Does the turbo 'sound' ok?? Post pics! |
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Somerville, Indiana | I hope it doesn't pertain to your engine, Cummins of old had
different timing sequence from different model years...We
went by the wrong sequence of A B C, and bent many push rods..
Cam shaft wasn't problematic in our Cummins, so that part may
be 'special' that we have seen..
edit: so a guess as to timing gear at the cam shaft?..Are you able
to test the timing of the cam shaft without pulling the head..
Edited by dave morgan 3/29/2020 09:30
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Idaho | You might be over speeding it without knowing it. Only takes a second to over speed, valve float and bingo bent push rod. Could the governor be getting "over active". good luck |
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Pierce county WI | That's what came to my mind is running fast, or weak valve springs. Unless, it's possible on a Deere engine the pressed gears can turn on the hub putting the cam out of time. That should have been noticeable though when they pulled the cam to change the lifters. |
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NC IA | Take this tid bit as conjecture, but I’ve heard of a bad crank pulley damper causing the cam gear to slip on camshaft. |
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SC Nebraska | On V8 natural gas irrigation engines, bent push rods come from worn valve seats. Just a thought. |
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Whitehouse | 324J used a 5030 engine if I remember right. Those engines use a friction washer and a bolt to hold the cam gear in place, it is not pressed or keyed in any way. I have seen a few of the 4 cylinder 2.4L cousins have a cam gear come loose and slip the timing resulting in bent push rods.
Not sure how you would check the timing without the right tools as there is a dummy pump that goes in place of #1 injection pump. When the pump lobe on the cam hits the dummy pump and stops, the timing pin should be able to be inserted into the flywheel.
If it is an engine with electronic unit pumps they are easier to remove and install. if they are mechanical pumps there is also a special tool to set pump position when installing it in regards to the fuel rack.
On edit, read some comments above, the lifters can be removed without removing the cam, when reinstalling used lifters however there is a bleed down tool that is used to compress the lifter before being installed, since the lifters were replaced though that should not be an issue. My money is on slipped timing.
Edited by JKM 3/29/2020 10:19
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Westside, IA | Few pics
 (2100BCE0-6FCE-44C2-B8E3-2D618FBD51CB (full).jpeg)
 (2C5DF5C5-0385-4E36-B62B-C578E67D1EA6 (full).jpeg)
 (019563FA-4EEC-44CF-92F0-1A6E567B6B41 (full).jpeg)
Attachments
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 2100BCE0-6FCE-44C2-B8E3-2D618FBD51CB (full).jpeg (177KB - 20 downloads)
2C5DF5C5-0385-4E36-B62B-C578E67D1EA6 (full).jpeg (276KB - 19 downloads)
019563FA-4EEC-44CF-92F0-1A6E567B6B41 (full).jpeg (272KB - 16 downloads)
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n.c.iowa | Initially I’d go with the slipped cam gear scenario. Probably see if you can determine if it has. |
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western iowa,by Denison | its a 5cylinder motor-sorry-only doing it on one hole-we replaced the rods and lifters on that hole and it fired right up and bent the push rod right away-takin head off next I guess-it had a slight tick like a gasket leak on the exhaust for a couple hours before this happened |
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NW Ohio,near Findlay | Is is possible that the head has been off before you owned it? A friend of mine had a Perkins 4 cylinder motor in a chipper. Head gasket was leaking water somewhere, never saw it. He had a buddy, said he could fix it for the money he owed him. They called me after it was together, would run, but terrible, backfire out the exhaust and intake. They didn't do any head work other than had another buddy check it if needed leveled, planed. They said it's OK, new gasket and slapped it on. without book, torques, nothing. When they disassembled it they pulled valve rockers off by just loosing the hold downs evenly and pulled them off, I do the same. When reassembling it in reverse, they tightened the hold down rocker bolts, good to go they thought. Since they didn't know the valve clearance specs, and no valve work, clearance would be OK.
Well owner now called me to bring book over and see what wrong. Pulled rocker cover off, rolled motor over, valve clearance was way, way off, on most of them, some valves were close, but most too tight. Could not figure it out, why some, not all. Push rods I assumed were all the same whether exhaust or intake, rockers were never taken off arms, nothing made sense. Only thing to due was to pull rocker arm off and pull push rods, see if anything wrong with push rods. We checked which valves were way off before removing, see if anything wrong on lifter. What we found was the stupid so called mechanic just cleaned the head and scraped all the junk down the lifter holes in the block, and on top of lifter. The guy that put it together said he did not do that, junk must have been there before and when he pulled push rods, the junk went on top of lifter.
We sucked out the lifter pockets with a long slender tube and block was clean, except head gasket material in lifter pocket. Like most motors with head on and no side cover on block, removing lifters not possible. Reassembled push rod and rockers, run the rack, set all valves, checked torque on head bolts. Motor run perfect, lucked out, no push rods bent or valve.
So in your case, see if anything on top of lifter in block. Maybe someone dropped something in the holes and holding push rod up off the seat in the lifter. I know nothing about that motor, cam timing could be off, but if that, I wouldn't think it would even start. Over speed would have to be way high before bending push rods. Rocker arms free on rocker shaft.
Post a follow up when you find out. |
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Boone, Iowa | Can you tell if all of the valve spring heights look the same? I have seen where a valve seat comes loose and can cause weird issues. |
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ec. nebr. | From your pictures I saw, I would remove the rocker arms on the bent cyl. and try to push on the valve and see if it moves freely??? Maybe it seized in the guide??? Does the valve have 2 springs? an inner and an outer? Maybe there is a broken coil in the spring?
Edited by flyboytoo 3/29/2020 11:34
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Texas | Usually when I’ve experienced a single bent push rod it was either a valve was stuck or there was a lifter failure.
When multiple bent pushrods occurred, that was from the timing gear breaking.
Sounds like your engine has an issue just on one cylinder if it’s just the one pushrod that keeps getting bent.
Check the valve, valve spring, and rocker arm carefully before pulling the head.
Yep, very well could be valve seat or even pieces of piston causing issues with the valve.
Edited by Pigpiggy 3/29/2020 12:39
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western iowa,by Denison | thanks-we replaced the lifter and push rod and still bent-I hope Adam takes the head off and we find something-it has around 5800 hours on it and does not use oil or water |
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West Central Iowa | A spun rod bearing could allow the piston to contact the valve(s) and bend pushrod(s). Most of the diesel engines I have seen with a spun rod bearing were described to me by the operator as having a noise high up in the engine which they thought was a valve train problem. On a diesel engine, most of the time what you hear is the piston contacting the head and not a rod bearing knock. Maybe this was the noise (tick) you heard before the pushrod bent. |
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n.c.iowa | I was wondering that pirlbeck, if on the exhaust/intake stroke it could throw the piston up higher. |
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Texas | I totally forgot about that possibility. Wonder if a bent rod could do anything to a valve? |
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E.Central MN | That sounds like maybe the valve wasn't completely closing, when you pull the head check to see if that valve or valve seat has been damaged. Hopefully it didn't damage the piston or the head, but it could have. |
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4cylinder diesel motor clatter-bent push rods-ok ?
