Help Me Diagnose an Engine Problem

[trook]

I own a 2009 JD4320 with 565 hours. Earlier today, I noticed that the engine seems to be running a little "rough". By that, I mean that if it is idling and you depress the foot throttle, it feels a little "rough" as the engine rpm's increase and it feels like it is missing a little. It also feels like is has a little less power and sounds slightly different. Almost like a 8 cylinder gas engine with 1 cylinder missing.

I don't notice this if I am at 1500 rpm and quickly accelerate to 2600rpm. It may have the same issue at the higher rpm's, but its hard to tell. If the issue is there, it is not as noticeable.

Since the fuel tank was about 1/4 full, I decided to fill up with fresh fuel, but it runs the same.

I didn't think the fuel filter would be the problem, but I changed it anyway. However, it didn't fix the problem. Also, the air filter is fine.

Suggestions?

 

[jd110]

Sounds like you might have a sticky fuel injector. You might try to add some conditioner to the fuel and see if that helps. I like the Lucas fuel conditioner.

 

[tomd999]

Hiya,

Is it throwing any error codes on the display? As noted, could be a injector on the way out but it could also be carbon build up in the exhaust port blocking flow, valve train part failure, (broken rocker, pushrod, lifter, cam lobe) or bad valve lash adjustment. May want to take a long handle screwdriver, put the tip on the top of the injectors and the handle to your ear, with it idling you should be able to hear the injector blow off it's seat and the knock of detonation of the fuel, listen for one cylinder with a slightly different sound, that's the one you start looking at first.

Tom

 

[trook]

Should I add some seafoam in case an injector is slightly clogged?

 

[whistlepig]

Could be sucking air into the fuel lines. That will make it miss. Look for fuel leaks. If it's leaking fuel it is sometimes sucking air.

 

[SPYDERLK]

Does it have normai power when its at rated rpm or does it bog easily?
larry

 

[trook]

It is not leaking fuel. If it is losing any power at pto speed, its not obvious. It appears to cut with normal power at pto speed. This evening, I was able to cut 5ft tall VERY thick grass. It bogged a little, but nothing I didn't expect.

 

[trook]

Re: *** Update*** Help Me Diagnose an Engine Problem

Well, after exhausting all means to diagnose the problem, I took it to the nearest dealer. They stated it had a "dead cylinder". Further, they are unsure of the cause, but believe the problem is most likely an injector, injector tip, rocker arm or push rod. The bad news is that it will take $400-$600 in labor just to be able to get into the engine enough so they can diagnose the problem!! They have narrowed the problem to "Cylinder 4". Depending on the cause, the price is obviously expected to increase.

I asked them if they have seen anything like this on a 4000 series Deere and they said no. They said that they NEVER have problems with the 4x20 series and that they are really good tractors. When I inquired about the warranty, they stated it was 2 yrs/2000 hours.

The tractor is 4 years old, but it has less than 600 hours and the original warranty goes to 2000 hours (within 2 years). I can't help but wonder if this is some type of defect. I should know more next week, but it sure would be nice if John Deere would cover this problem considering only 585 hours are on the tractor even though the "time" expired at 2 years.

 

[logankelly]

so if you have a car with bad engine that has 70,000 miles on but is only 2 years old and is within the 36 month but exceeds the 36,000 miles warranty should car company honor the warranty.

 

[trook]

I'm mostly wanting to update everyone that attempted to help me troubleshoot the initial problem.

To follow up on the question posed by logankelly, I believe the better comparison would be quite the opposite: A car that has exceeded the 24 month portion of the warranty but has only acquired 10,000 miles of the 100,000 mile portion.

I understand that they don't have to honor anything. However, I am curious to see whether or not they will see this as a defect that should not have happened (which it obviously is) with such low "mileage" and demonstrate that John Deere does actually value their reputation, name and the quality of their product by doing the right thing.

If so, should they respond in a reasonable and prudent manner? Or, should they say .....sorry.... I don't care how few hours you have, how well you have maintained your machine or how much we imply that our tractors are better than all others combined- you have exceeded the 24 months portion of the warranty and are completely on your own regardless of any mechanical defect that may exist with our product. By the way, can I interest you in this new and improved model that just arrived on our lot????

 

[logankelly]

didnt want to put a burr under your saddle with that post. you orginal owner? takes less than a hour to pull hood off and the injector out maybe you can do that yourself, just a thought, Kept us post on your results

 

[jeffster]

it never hurts to ask, especially if you are polite about it. I lost the turbo on my truck at 6 years and 92k miles, so well outside the 3/36k coverage. I called the customer service line of the manufacturer and explained I have taken care of my truck and I have bought a number of vehicles from them and was there anything they could do to help? They offered to pay for half of the repair (almost $4k), or give me an extra $8k off a new vehicle on top of my current discount level and current rebates. Not saying it is going to work every time, but worse case is you wasted a few minutes of your life trying.

 

[trook]

On the Compact 4320? The dealer told me it was more complicated than on the older tractors and that it involved approx 6 hours of labor. I hope they are not pulling my leg.

 

[wacummins]

On the Compact 4320? The dealer told me it was more complicated than on the older tractors and that it involved approx 6 hours of labor. I hope they are not pulling my leg.

It is more complicated by a long shot. Each injector is also its own injector pump. I don't know if it would take 6 hrs to tear down, but I can believe that it will take that to change it out and re-time the injector pumps to the rack etc....

William....

 

[tomd999]

Hiya,

Hmmmm, betcha it's the injector or one of the electrical connectors to it that's your issue.

Modern injectors operate under higher pressures and have much smaller passages, any contamination of the fuel may result in clogging. The current generation are Multiple Event Digital Injectors where the ECM triggers multiple injection events during the combustion cycle starting with a "pre burn" event to "soften" the knock of a direct injection Diesel and then 4 or more injection events as the piston descends in the bore during the power stroke providing more uniform cylinder pressure and thus more torque output with much less wasted fuel and emissions. This is why Diesels sound so different nowdays, gone is the ear shattering knock at idle of the mid '90's in-line direct injected Cummins.

That being said, and I may be wrong on this as I haven't seen your tractor and I'm not 100% sure if Deere was using multiple event digital injectors on your model year, but the newer injectors "should be" pretty simple to change out as the "adjustment" is taken care of by the ECM and all the mechanic needs to do is swap the physical part and connect it up.

Tom

 

[trook]

William,

Deere told me the same thing. Each injector has its own pump and that they all have to be timed together which increases the labor. He didn't say anything about the computer automatically timing everything and implied it was somewhat of a lengthy and detailed process. It seems unusual to me that I am having this issue with less than 600 hrs on the tractor. I should know the specific problem by the end of next week.

Thanks for all your input and assistance.

 

[wacummins]

William,

Deere told me the same thing. Each injector has its own pump and that they all have to be timed together which increases the labor. He didn't say anything about the computer automatically timing everything and implied it was somewhat of a lengthy and detailed process. It seems unusual to me that I am having this issue with less than 600 hrs on the tractor. I should know the specific problem by the end of next week.

Thanks for all your input and assistance.

Yep your problem and the one other I have read about scare the crap out of me as I also have a 4320! Your engine dose not have an ECM, its injection is all mechanical. The pumps run off the cam and are controlled by a rack that interconnects them. On the bottom of the pump is a roller like you would find on a roller valve lifter. The other one I read about that roller was destroyed and it took out most of the engine! You may have noticed that when your tractor starts it sounds different for a few seconds, this is due to the cold start advance running the control rack and adjusting the timing. In 2009 the 4520 and 4720's went to an "E" version of the engine and have some electronic control of the system, I'm not totally sure how much was changed out tough as they still appear to have the mechanical injector pumps, maybe just the rack is now controlled by the ECM?? In any case my engine service manual dose not cover the new design so I'm only guessing about their operation

I do know that if I ever have to change out any of the injector/pumps out on mine I will "tune" mine to the pre 2009 4720 specs and add the correct turbo and intercooler.

Hopefully your problem will be some slight problem with the injector and not too $$$. And no you shouldn't have some thing like this happing on a low hour machine. As I recall the other tractor was also rather low hr's too.

William....

 

[tomd999]

Hiya,

All I can say is Wow!

I had no idea that Deere would still be using a mechanical "rack" system like the old Big Cam Cummins from the late 70's on the 4x20 series engines. How are they making Tier 4 with close to 40 year old tech???

If I was in the market for that chassis size, I would not even consider a Deere if that is the case.

Tom

 

[Tx Jim]

It is more complicated by a long shot. Each injector is also its own injector pump. I don't know if it would take 6 hrs to tear down, but I can believe that it will take that to change it out and re-time the injector pumps to the rack etc....William....

I just looked up the individual inj pumps. Reman ones re $275 ea.

 

[wacummins]

I just looked up the individual inj pumps. Reman ones re $275 ea.

Yep they are not that $$$ I have even seen new parts (OEM) new for about that price point. I bet a good pump shop could re-"MAN" the stock 4320 parts to the 4720 specs for a few hundred $ for a set of 4.

I wish the original poster would update the status of his machine, I would like to know what the problem was/is and the damage $$$

William....