John Deere 6068L EGR

[partsandservice]

Can anyone tell me what caused this? Before break down the engine had an obvious fuel knock.

 

[equip guy]

At a glance it appears that you possibly had too much fuel dumping into the first two cyl from Lto R. Possible faulty injectors. The fuel appears to have "washed" any soot/carbon that should more look like thr first two R to L. How many hours are on the engine? and have you done any cleaning to the pistons before submitting pic?

 

[partsandservice]

Fuel wash yes. 4400 hrs. The only cleaning was done with a shop rag, no cleaning agent or abrasives. I was thinking it could be a fuel timing issue. At this stage I am going to replace high pressure fuel pump, rail relief valve and all six injectors, however I fear that there may be programing issues. The high pressure pump has its own timing sensor and there is also a crank sensor. No codes were present. Also there was no noticable exhaust smoke. I did find slight wear on the ends of the push tubes. I also adjusted valves and ran engine before tearing it down. They will be replaced along with cam followers. I have posted here hopefully to get insite as to the cause so this does not happen again. The progression of the "wash" is what has me wondering. Worst on 1 and progressivly lighter to 6. Same thing with push tube wear. Also the head is at the machine shop.

 

[Iron@Dirt]

Think it would be worth checking rod and main bearings?

 

[equip guy]

From experience, when any one of those sensors act up they usualy throw a code. Not being in your shoes I don't know how much time you can afford with machine down or cost of parts, but I would perform a couple of things. First obtain fuel pressure specs and test output on each injector line, second if you have the resource, do a injector blow off test and check spray pattern. I do have the pump service manual and can check next week on any other specs. Did you happen to notice your timeing mark placement prior to removing? This would be a basic check to see if it had jumped. You said you had no codes, but did you check pending dtc's from the ECM?

 

[cutting edge]

Have you thought about getting your local Deere dealership involved?

You're gonna have to have them come out and calibrate the new injectors anyways.

Burning any coolant in that engine?

 

[partsandservice]

Pending codes? Only saw active and stored codes. I have not removed the fuel pump yet. I did however time the engine and check the timing mark. dead on. None of the pump shops around here have the tooling to check these injectors yet. This will be the third one of these engines I have been into. I think we caught this one in time as both of the others dropped valves on the number one cyl and this one shows the most spray mark on number one. I would be good to check the bottom end but greenbacks are in short supply. As far as john deere goes when they come to program the injectors they are also going update the program and I think the reprogram is related to the EGR. Its good to find a forum with people that have knowledge and hope I can share some of mine. If time allows, I will post pics of the push tubes to show the wear progression from one to six on monday.

 

[cutting edge]

Burning any coolant in that engine?

????

 

[partsandservice]

Did not mean to leave out cutting edge, No coolant loss currently. About 1000 hrs previously, the egr cooler busted and since its replacement have had no more coolant loss.

 

[equip guy]

This will sound a little odd, but when John Deere comes out, MAKE SURE that the flash update for the engine (injectors) is for the relevant machine. By this I mean Premium/non Premium, Quad box, sync shuttle ect. I recently had a 6230 that had transmission troubles. Showing low trans pressure at idle. When brought up 300 rpm's machine would stay in motion. JD cooporate thought it needed a reprogram and when it sent the update it did so with out making sure it was of the same tractor. Although engine and trans were the same on the update the other features like heat-A/C, blower, and other functions were wiped out during the program, which resulted with a new $500 module to be replaced, labor and mileage. Of coarse this was a goof up on cooporate, the tech didn't confirm, and I had one pissed off operator working in 100 degree heat cutting hay. This program also altered some engine controls too. The problem resulted in a bad transmission gasket between valve body causing fluid to divert to another port, thus cutting out pressure at idle/low rpm useage.

 

[partsandservice]

Going Back

Head reinstalled , Reman injectors, New push tubes.

 

[StanRAUUS]

Possible root cause IDID, internal deep injector deposits
JD http://www1.eere.energy.gov/biomass/pdfs/Biomass_2009_Adv_Biofuels_III_Stiffler-Clause.pdf
http://www.lubrizol.com/9040Zer0/Performance/DieselInjectorDeposits.html

 

[partsandservice]

Thanks for all the input. I believe the problem was this IDID. I concentrated on the fuel system and she runs out great. Fuel additve will be used from now on because of the ULSD. I could not tell a difference in performance before or after the injectors were calibrated.

 

[Nige]

Amazing how many allegedly "modern" engines don't like to run on ULSD .... you'd think their fuel injection systems would be designed around it.

 

[Quality]

Parts & Service,

Thanks for the pictures and tips. I have a 6068L in my shop out of a 748H and we are doing a complete overhaul. I will certainly have the injectors remaned.
Quality Equipment & Parts, Inc.
Lake City, FL

 

[partsandservice]

I know of y'all . I see your ads in the SLT. If you pull the gear train down, be sure to time the idler gear as the pump/cam sensor reads off the back of this gear(it is the same size as cam gear. Look close at push tube ends and cam followers. I adjust valves to.010 intake and .014 exhaust band all that nasty overhead noise goes away. Other than. That it is just a 6068 powertec