Engine knocking ..bang bang bang..

[olink]

Looking for help in diagnoses before I tear into this thing. Have a FarmPro 2425 with Y385 engine. Most recently been grading and land clearing. Have a couple of small hydraulic leaks, so before the long day began, I topped off the rear Hyd for the drag box operation. Just a few minutes into working, I backed into a stump and bent dragbox braces and stopped the engine while I attemped to straighten braces. Needed tools, so I headed back to the garage with the tractor. About 100 yds later, the engine started a load knocking. I shut it down immediately. checked oil and found it to be about 2qts high...over filled. Drained the oil and put in new oil to proper levels. Started just fine, but the loud knocking continues. Never got any indication of overheating, had good oil pressure. Engine only has about 40 hours on it. I used to rebuild VW engines as a young man, kind of sounds like I dropped a valve? I have absolutely NO experience with diesels. Anyone want to give me a starting point? Pull the valve cover? Or could this be some sort of a fuel issue causing the knocking?...like a misfire? Oh, tractor is out of warranty, bought in April of 2003. Suggestions/comments very welcome and much appreciated. OLY

 

[billbill1]

Oly, how did it get overful on oil? I wonder if it got in through the hydraulics somehow. I have no clue on what could have happened, maybe Greg or Chip will be able to help. Sorry

 

[Surge]

Olink,

If you were sure the original oil level was correct, ie: you did not originally over fill the crankcase and was found to be significantly above the fill level, then you can narrow it down, there are only so many fluids in the tractor.

1) Smell the oil..... if it smells like diesel, you have fuel leaking into the crankcase... bad seal, injector pump... something...

2) If it appeared to be seperated...maybe coolant... again smell it... if it had normal antifreeze, it will have a pungent, almost sweet smell and you should see the coolant float on the oil. Again, it is a front seal or cracked block letting the coolant from the block into the crankcase.

3) If you see two grades of oil... again some separation of oil, heavier engine oil and thin oil ( it could be Hydraulic oil) let the oil settle out, in a clear container... the lighter hydraulic oil should rise to the top and you will see the gradiant separation... Not sure the old smell test would work on this check.... Again, some seal has blown to allow the mix... Check the level in each of the above reservoirs, it may also give you an indicaton the the mysterious fluid....

You can then go from there on repair, based on the fluid type...

 

[greg_g]

</font><font color="blue" class="small">( the engine started a load knocking. I shut it down immediately. checked oil and found it to be about 2qts high...over filled. )</font>
First guess is hydraulic pump seal blew. Check your hydraulic reservior, see if it's down about two quarts.

//greg//

 

[JohnS]

Especially, if after running again, it is high on oil and hyd tank is low. Fuel and coolant are possibilities, but the most commmon is the hhd pump seal goes, and the hyd oil fills the engine. See: this web page

 

[SPIKER]

I like all the suggestions so far. these things are pretty tough tractors but have a few weaknesses. the Hyd Pump seal & primary pump line routing is one of them. the QD from the pump the the FEL may have came loose this blows the seal and dumps hyd fluid past the seal into the crank case by means of the common pump drive gear to engine crank gear that are actually in the engine crank case.

one quick check is to see if the hyd sstem is still working. if it is then the QD may not be the problem but somethign farther down line. I have not checking in the valve cover on mine, (neglected the 50 hr service of valve lash adjustment and head bolt re-torque.) thew injection pump shouldn't get fuel into oil, but it does fet fuel into the injection pump oil. (see johnS's site as linked above.) read all that info there and get the recogmended things done... the rest is minor tune up stuff nad common since running. these engines are not some high tech honda miltiport 30 valve thing... just more like the old 50's tech pretty similar to the VW ones of past...

others have described a fuel problem similar to this but not WITH the engine oil over fill probl.. the guys here and at NYCTOA site are great info and will help in any way possable.

MarkM /forums/images/graemlins/smile.gif

 

[olink]

I overfilled the hyd res about an hour prior to this occurance. I'm pretty sure it has something to do with that since the res is low again. I have a couple of small leaks and since I was headed out for the day with the tractor, I thought a bit over fill wouldn't hurt??? Thanks for the reply..sorry I didn't get back sooner, been busy with the military...

 

[olink]

Sure appreciate you replying. I've been busy with military stuff and haven't been able to get to the tractor repair. I'm sure the oil level was correct, because I check it everytime I use the tractor and I had just changed the oil about 3 weeks before (6 hours). I saved the oil from this occurance, so I will check to see if there is any separation of fluids. I'm thinking this is a blown seal between the hyd pump and crankcase? I don't have a good repair manual, so I don't know the different paths hydro could take into the case, but That seems to be a logical starting point. Thanks for your patience on my reply. I'll let you all know what I find out. It's raining like crazy here today, so this may be another delay day!

 

[olink]

Greg, the hyd res is definitely low... and I don't see any major spills on the ground between the garage and the work site (about 300 ft away) so, I think you have hit it on the head! Probably the seal between the pump and the case. Thanks .

 

[JimR]

Let's hope you didn't do any serious damage to your tractor motor.