iDRY Vacuum Kilns

Sponsors:

john deere 440a with a 4239d slight knock after rebuild

Started by duckslayingpro, January 31, 2012, 07:43:49 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

duckslayingpro

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

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

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

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

1994 Ford L9000
2004 Tigercat 718
1998 Barko 225
1999 John Deere 748G
FEC 1550 slasher
CTR 314 Delimber
Sthil 461
Sthil 250

sealark37

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

doghunter

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

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.
Third generation logger, owner operator, 30 yrs felling experience with pole skidder. I got my neck broke back in 89, left me a quad. The wife kept the job going up to 96.

duckslayingpro

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

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

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.
Third generation logger, owner operator, 30 yrs felling experience with pole skidder. I got my neck broke back in 89, left me a quad. The wife kept the job going up to 96.

Ford_man

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

snowstorm

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

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

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

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
 
Al Raman

OntarioAl

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
Al Raman

Shotgun

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
Joined The Forestry Forum 5 days before 9/11.

pineywoods

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.
1995 Wood Mizer LT 40, Liquid cooled kawasaki,homebuilt hydraulics. Homebuilt solar dry kiln.  Woodmaster 718 planner, Kubota M4700 with homemade forks and winch, stihl  028, 029, Ms390
100k bd ft club.Charter member of The Grumpy old Men

snowstorm

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

lumberjack48

I would pull the head, most likely bent valve stems to, it all most has to be timing gears are set wrong.

I rebuilt a 292 Ford, when we went to start it, it blew out of the carb and sucked in the exhaust. [ don't laugh ] When i had put the timing chain on the motor was up side down.
Third generation logger, owner operator, 30 yrs felling experience with pole skidder. I got my neck broke back in 89, left me a quad. The wife kept the job going up to 96.

kiko

Multiple bent push rods?  Cam out of time or engine was not timed properly during valve lash adjustment.  Top center number one: Intake and exhaust cly 1 , Intake cly 2 ,Ex cly 3. Rotate crank 360 deg,   Ex cly 2 , Intake cly 3,  Intake and Ex cly 4. Not sure of lash but propably Intake .014  Ex .018.  If cam is timed properly vales should be overlapped on whish ever cly is at TDC. cam off a couple of teeth would cause engine failure but not bent push tubes. Hope this helps.

duckslayingpro

Well took head off and looked at valves everything looks to be good. A friend who used to be a john deere mechanic timed engine for me. I asked him about it. He seems to think the pushrods may have bent from the old block. I had to get a new crank, block, and head from schafers enterprises. The old block had a rod threw through it. News rods and everything installed in new block. I did reuse my pushrods and rocker arm and injection pump from old block. Oil presaure is holding around 30-40 lbs
I guess my next question is do you all think the pushrods could have.already been bent? The pushrods are not  very visually bent. Rolling them on the table is only way i can see that they are bent.Wish i would have checked them before putting them in engine. Live and learn i guess... Guys thanks for all the help. This is a great forum!

sandhills

Those valves may resemble the pushrods in the fact it could be hard to tell if they are bent, the first thing I would do is "dummy" up the engine and crank by hand, obviously there should be no lock up what so ever.  Did the top of the pistons show any sign of hitting the valves?  Maybe not even possible on these engines?

kiko

duckslayingpro, I forgot to mention this the other night.  With the head off you can roll the engine untill the number one piston comes up. Now drop four new push tubes into the cam followers on clys 1 and 2. If the cam is timed correctly the first second and forth push tubes will be the same height with the third one sticking up higher( counting from the  fan)  If this does not happen, roll the engine one revolution and look at the push tubes again if you still don,t have the three of them level with third one higher your cam is out of time.  And yes I think the tubes could have been bent from the previous engine failure, but if valve lash was set correctly to begin with it is unlikely that they bent more to give the 1/8 gap you spoke of before . So, what I am trying to say is a slight bend in a pushtube can usally be adjusted out but should not be run for any extended period.

Thank You Sponsors!