4120 Engine problem- Any Ideas?
- Thread starter GalwayBoy
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clarityconnect
Member
I'll second that as I'm about to receive my new 4120 in about a week and I'm naturally anxious to see how this episode ends or is satisfied. Hope everything ends well and that JD is resposive to this situation/problem.
I picked up the tractor yesterday.
Turned the key, and she revved right up and blew a puff of black smoke. Seemed to run much smoother than before, and with more power. I turned the manure piles with the loader when I returned home, and was satisfied with the power. Just finished up three hours of mowing and had no issues.
The service manager was not in when I called, and in fact, the dealer was closed when I put it on the trailer.The guy with whom I spoke said that they did some work to the rack. The rectangular access cover on the front of the engine has obviously been removed and is newly sealed.
I intend to give a call tomorrow, and ask specifically what was done.
In any case, it's good to have it back! Things were starting to look pretty shabby around here.
Jon
Turned the key, and she revved right up and blew a puff of black smoke. Seemed to run much smoother than before, and with more power. I turned the manure piles with the loader when I returned home, and was satisfied with the power. Just finished up three hours of mowing and had no issues.
The service manager was not in when I called, and in fact, the dealer was closed when I put it on the trailer.The guy with whom I spoke said that they did some work to the rack. The rectangular access cover on the front of the engine has obviously been removed and is newly sealed.
I intend to give a call tomorrow, and ask specifically what was done.
In any case, it's good to have it back! Things were starting to look pretty shabby around here.
Jon
AKfish
Super Member
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- 5,419
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- Alaska
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- JD 5115M; JD 110 TLB; JD 4720; Ford 9N; JD X300R
Thanks Jon, for the follow-up info.
Help me out, though... what's the rack? I recall that early diesel engines had a common-line fuel distrubution to the cylinders known as a rail --- but I don't know what a rack is.
Appreciate hearing about your 4120 problem and how you managed to take care of it.
AKfish
Help me out, though... what's the rack? I recall that early diesel engines had a common-line fuel distrubution to the cylinders known as a rail --- but I don't know what a rack is.
Appreciate hearing about your 4120 problem and how you managed to take care of it.
AKfish
AK,
Sorry to disappoint you, but I know about as much about the workings of this fuel system as you do.
I called the dealer yesterday, but the service manager is on vacation this week, and he's the guy who handled my repair. I'll contact him when he's back in the shop and try learn what was done, and some info on the mechanics of the system.
Jon
Sorry to disappoint you, but I know about as much about the workings of this fuel system as you do.
I called the dealer yesterday, but the service manager is on vacation this week, and he's the guy who handled my repair. I'll contact him when he's back in the shop and try learn what was done, and some info on the mechanics of the system.
Jon
Green is Keen
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- Guess...! It's green and rimes with "Cold Beer".......
Jon,
Sorry I tuned in late, but glad to hear you got it fixed.
As I read through the thread I was thinking that a lack of fuel to the front cylinder was the reason for loss of power. My guess would have been a failed injector. When the shop "Runs the Rack", they are adjusting the lash in the valve train, which not only opens the exhauste & intake valves, but triggers the injector as well.
No more hours than you have on the engine, someone must have failed to tighten a lock nut.....
Sorry I tuned in late, but glad to hear you got it fixed.
As I read through the thread I was thinking that a lack of fuel to the front cylinder was the reason for loss of power. My guess would have been a failed injector. When the shop "Runs the Rack", they are adjusting the lash in the valve train, which not only opens the exhauste & intake valves, but triggers the injector as well.
No more hours than you have on the engine, someone must have failed to tighten a lock nut.....
Just an update-
Was at the dealer to get hydro oil and some filters in order to do engine and trans oil change, and got to speak briefly my service rep. He also said they worked on the " rack", although he didn't personally work on it. I asked about a subsequent hiccup that occurred while under load, and was told that all the 4x20 tractors do that- even new units on the lot with no hours.
They apparently dyno'd the machine after completion of the work, and are satisfied with its operation.
I'll post a followup if needed.
Thanks for everyones posts!
Jon
Was at the dealer to get hydro oil and some filters in order to do engine and trans oil change, and got to speak briefly my service rep. He also said they worked on the " rack", although he didn't personally work on it. I asked about a subsequent hiccup that occurred while under load, and was told that all the 4x20 tractors do that- even new units on the lot with no hours.
They apparently dyno'd the machine after completion of the work, and are satisfied with its operation.
I'll post a followup if needed.
Thanks for everyones posts!
Jon
RRacing
Gold Member
I had the same problem but with some added smoke. It was fixed by the rack and injector timing. I got a recall and they had to replace the pump springs and its almost as bad as it was before. They have new specs for the rack and my dealer refuses to adjust it back to were it was as per JD . After owning 5 John deeres I think this will be my last. 3 of the other 4 were jewels. This one has lemon written all over it!!!!
AKfish
Super Member
- Joined
- Oct 1, 2004
- Messages
- 5,419
- Location
- Alaska
- Tractor
- JD 5115M; JD 110 TLB; JD 4720; Ford 9N; JD X300R
RRacing -- sorry to hear that you're having problems that your dealer won't address.
Adjusting the "lash" on the valves is a relatively easy exercise. Some good wrenches, a screwdriver and a feeler guage. Probably have to replace the valve cover gasket, too. The hardest part is advancing the cylinder's to adjust each set of valves. Need a 1/2" drive ratchet and socket on the crankshaft pulley and maybe a short "cheater".
I haven't kept up with the shop talk --- so, didn't know that "workin' the rack" meant adjusting the valves --- oh, well; I'm gettin' to be an ol' fart anyway...
That said, I don't know if your tractor is still under warranty, but given that you have an established track record of purchasing multiple tractors and implements from JD; I would like to believe that someone, somewhere in the corporate food chain would be very interested in keeping you as a loyal customer.
Don't roll-over on this until you're satisfied that your tractor is working the way it was designed to work!!
AKfish
Adjusting the "lash" on the valves is a relatively easy exercise. Some good wrenches, a screwdriver and a feeler guage. Probably have to replace the valve cover gasket, too. The hardest part is advancing the cylinder's to adjust each set of valves. Need a 1/2" drive ratchet and socket on the crankshaft pulley and maybe a short "cheater".
I haven't kept up with the shop talk --- so, didn't know that "workin' the rack" meant adjusting the valves --- oh, well; I'm gettin' to be an ol' fart anyway...
That said, I don't know if your tractor is still under warranty, but given that you have an established track record of purchasing multiple tractors and implements from JD; I would like to believe that someone, somewhere in the corporate food chain would be very interested in keeping you as a loyal customer.
Don't roll-over on this until you're satisfied that your tractor is working the way it was designed to work!!
AKfish
