Author Topic: john deere 440a with a 4239d slight knock after rebuild (Read 1355 times)

duckslayingpro · « **on:** January 31, 2012, 07:43:49 pm »

Hi all. I just recently rebuilt my 4239d new main bearings, crank turned, new pistons, liners, etc. Done everthing to the Tech manual specs. Got the motor dropped back in the skidder. Bled the fuel lines fired right up sounded good. Ideling around for the first few minutes per break in instructions. After a 10-15 minute period I started hearing a slight knocking type sound. Almost sounds like it is in the head but cannot be sure. Any ideals would be greatly appreciated.

I thought maybe I had injection pump timing advanced to much so I retarded the pump. no change...
Thanks
duckslayingpro

duckslayingpro · « **Reply #1 on:** January 31, 2012, 07:47:03 pm »

I shut the motor down after this knock started.
Also motor is not getting hot. only got to around 165 degree on temp gauge and no blowby or anything like that.
Thanks again.

Bobus2003 · « **Reply #2 on:** January 31, 2012, 09:00:49 pm »

Is it Rocker Arm noise? I just rebuilt the 3304 CAT in our 518 at work and after about a half hour of running it got alot of rocker arm noise.. Don't quite have them adjusted right. But have well over 100hrs on it now without issue

duckslayingpro · « **Reply #3 on:** January 31, 2012, 09:08:08 pm »

I would say it would be possible. I am gonna try and listen to it closer to try and pinpoint but it does kinda have me stumped. The "knock" or sound does speed up with rpm if that makes any difference.

treefarmer87 · « **Reply #4 on:** January 31, 2012, 09:18:43 pm »

check the timing and it might be a bent valve

sealark37 · « **Reply #5 on:** January 31, 2012, 09:38:19 pm »

It could be a bad injector nozzle. The affected cylinder should be cooler than the others.

doghunter · « **Reply #6 on:** January 31, 2012, 11:17:48 pm »

i had one do exactly the same you have an injector dribbling if you run it it will cook the affected cylinder pull the injectors and have them checked probably u broke loose a very tiny piece of debris in the fuel system and it is now in one of the injectors u may be able to pull the exhaust manifold and see which cylinder is smoking or spitting out raw fuel dont work it or you'll need a new cylinder kit for the affected cylinder I LEARNED THE HARD WAY

lumberjack48 · « **Reply #7 on:** February 01, 2012, 09:08:59 am »

Quote from: sealark37 on January 31, 2012, 09:38:19 pm

It could be a bad injector nozzle. The affected cylinder should be cooler than the others.

When its running feel the exhaust manifold where it comes out of the cylinder, the cool one will be the one thats misfiring.

duckslayingpro · « **Reply #8 on:** February 01, 2012, 09:29:00 pm »

I didnt get to go out to.the skidder today. Hopefully i can tomorrow. But it may be saturday. I will check everything you guys have stated. Thanks for thr replies.

sandhills · « **Reply #9 on:** February 02, 2012, 12:24:03 am »

You'll laugh but this really does work, take a screwdriver and put the handle in your ear, put the other end on the top of each injector while the engine is running, if one isn't working you'll hear the difference, working injectors have a distinct sound. Only other thing I can offer is we had a camshaft go bad and it would make a "thumping" sound out of the air breather, one of the exhaust valve lobes went bad so it was trying to push everything out and pull in through the same valve, also created a lot of soot in the intake manifold.

lumberjack48 · « **Reply #10 on:** February 02, 2012, 10:48:33 am »

The old mechanics used a Axe handle or something in the order to pin point a knock in a motor.
One end on the motor, the other end against your ear.

Ford_man · « **Reply #11 on:** February 02, 2012, 06:27:07 pm »

I had a JD that broke a rocker arm it knocked and it also smoked when it pulled just a little.

snowstorm · « **Reply #12 on:** February 02, 2012, 07:41:33 pm »

Quote from: duckslayingpro on January 31, 2012, 07:43:49 pm

Hi all. I just recently rebuilt my 4239d new main bearings, crank turned, new pistons, liners, etc. Done everthing to the Tech manual specs. Got the motor dropped back in the skidder. Bled the fuel lines fired right up sounded good. Ideling around for the first few minutes per break in instructions. After a 10-15 minute period I started hearing a slight knocking type sound. Almost sounds like it is in the head but cannot be sure. Any ideals would be greatly appreciated.

I thought maybe I had injection pump timing advanced to much so I retarded the pump. no change...
Thanks
duckslayingpro

did you use deere parts? already had the rings on the pistons in the liners? how much force did it take to seat the liners? were the wrist pin bushings miked? snap rings ok thet can be installed backwards most dont know that. if that motor came in that skidder new its a 219. you dont just advance the timing on a diesel no no no. you had the crank out are you sure the timing marks line up?

oil pump ok? how much pressure? did you do all the work? experinace? could be a dozen different things. if turningthe pump helped then maybe the timing marks are off

duckslayingpro · « **Reply #13 on:** February 04, 2012, 06:07:06 pm »

I checked on the fuel related testing injectors tested good. Looked at valves. They were way out of adjustment they had like an 1/8" of play. Adjusted them to spec. Started the motor. Knock was gone for a few minutes only to return. Pulled tge rocker arms off and pulled the pshrods. Everyone of them is bent. Will try new pushrods and checking valves again before startup. Will order pushrods monday. Hopefully they will be in quick. Thanks guys!

snowstorm · « **Reply #14 on:** February 04, 2012, 06:59:34 pm »

now the question is why did they bend?? how fast dose that motor turn? should be 2500rpm. had a 580 case bend one after the keepers came off the valve stem valve hit the piston made quite a mess

OntarioAl · « **Reply #15 on:** February 05, 2012, 09:15:54 am »

If all the push rods are bent something is seriously wrong and before putting in new ones, I would pull the head and have a look and see if the valves are striking the pistons.
snowstorm poses some good questions

Quote from: snowstorm on February 02, 2012, 07:41:33 pm

Quote from: duckslayingpro on January 31, 2012, 07:43:49 pm
Hi all. I just recently rebuilt my 4239d new main bearings, crank turned, new pistons, liners, etc. Done everthing to the Tech manual specs. Got the motor dropped back in the skidder. Bled the fuel lines fired right up sounded good. Ideling around for the first few minutes per break in instructions. After a 10-15 minute period I started hearing a slight knocking type sound. Almost sounds like it is in the head but cannot be sure. Any ideals would be greatly appreciated.

I thought maybe I had injection pump timing advanced to much so I retarded the pump. no change...
Thanks
duckslayingpro
did you use deere parts? already had the rings on the pistons in the liners? how much force did it take to seat the liners? were the wrist pin bushings miked? snap rings ok thet can be installed backwards most dont know that. if that motor came in that skidder new its a 219. you dont just advance the timing on a diesel no no no. you had the crank out are you sure the timing marks line up? oil pump ok? how much pressure? did you do all the work? experinace? could be a dozen different things. if turningthe pump helped then maybe the timing marks are off
In any event I would not try to restart the motor until the cause of the bent push rods is determined.
My 2 cents
Thanks
Al

OntarioAl · « **Reply #16 on:** February 05, 2012, 09:19:44 am »

Sorry folks
I messed up the quote and inserted my final comment in Snowstorms comments.
In any event I would not try to restart the motor until the cause of the bent push rods is determined.
My 2 cents
Thanks
Al

Shotgun · « **Reply #17 on:** February 05, 2012, 09:47:35 am »

Al, you could also have edited your post in Reply #15 to make it meet your needs. Quite a few folks put their comments about the quote in the quote box. Don't feel bad, at least you recognized it. Good job.

Norm

pineywoods · « **Reply #18 on:** February 05, 2012, 03:06:04 pm »

If all the pushrods are bent = camshaft - crankshaft timing. Timing gears or chain not installed properly. Very easy to do if the gears are spiral. Not saying how I know...Usually results in bent valves also.

snowstorm · « **Reply #19 on:** February 05, 2012, 03:59:14 pm »

Quote from: pineywoods on February 05, 2012, 03:06:04 pm

If all the pushrods are bent = camshaft - crankshaft timing. Timing gears or chain not installed properly. Very easy to do if the gears are spiral. Not saying how I know...Usually results in bent valves also.

no timeing chain its gear driven it could off a bit it would explain a lot

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Author Topic: john deere 440a with a 4239d slight knock after rebuild (Read 1355 times)