A funny thing happened to my X485 yesterday

[awlchu]

After mowing grass for ~ 2hrs I decided to take a break. I returned to my tractor within 10minutes and started it. Without warning the idle would not settle down, similar to a rpm "surging" effect.

Speed up then drop, repeat. The only way to keep the rpm steady was to give it a full throttle and *eventually* it would settle down to a constant rpm (as expected).

Notes:
Does not do this when cold
Only surges after sitting a few minutes warm, does not do it if I shutdown and restart the engine, rpm remain steady.

hrs <30hr on this new tractor.

I plan to contact the dealer for warranty but before I do that are there any simple checks I can perform before hand?

 

[al3]

Run, don’t walk, to the dealership before the warranty expires. I had a 485 for just under 3 years; it developed a 45-75 second surge problem at the 30 hours point. Checked inlet temp sensor resistance (nominal) and plug wires/caps at home, which is about all you can do yourself. (Shop manual procedure to check out EFI is to replace it with a known good one) Unit spent a lot of time at the dealership which was never able to run down the problem. They replaced injectors & EFI module to no avail. Finally gave up on the unit….
I’ve corresponded with a few other folks with the same issue. Two of them said replacing the entire throttle body assembly (body, valve and shaft) fixed the problem for them. That can’t be a cheap repair, so by all means take the time to address it before your two years is up. Good luck and post the fix if/when you find one.

 

[DJLX]

I was one of those that had a surge problem with my X585. It appears that the butterfly valve in the throttle body would bind up causing the governor to react making it surge. It would just rev up and down. In the beginning it would happen only occasionally and I took it to the dealer and it didn't do it, naturally. I kinda diagnose the problem by squirting wd 40 at the valve bearings and finally when it was bad enough took it back to the dealer. They replaced the throttle body after they couldn't understand why it was doing it but that fixed the problem.

 

[awlchu]

Good advice, I called the dealer and they are picking up the unit on Friday.

And I will post on this board their findings........

 

[CableGei]

My X585 does that occassionally. I've got 300 hours on it and it's probably done it 5 times. I took it to the dealer once and they couldn't duplicate it.

Should I be persistant and take it back again? I've got about 3 months left on my warranty.

 

[al3]

Yes, I’d get it addressed----my surging eventually lead to backfires which then damaged a fuel injector.
My 485 surged only on start up after it had cold soaked when the temps were +5 F and below. Problem wouldn’t appear after it had warmed up or when the temps were higher than 5. Part of the challenge was getting it to the dealer when air temps were cold enough to replicate the problem. So they’d work on it, then have to wait for cold weather to see if it was fixed. Meantime snow is falling and my drive has to get blown. So it didn’t get fixed. Then the surging began to be accompanied by backfires, which can damage fuel injectors ($100+ each). Which it did. By this time unit is out of warranty, Deere agrees to cover parts, not labor. Dealer stopped charging for labor after the first unsuccessful attempt to repair. After 4 trips to the dealer (60 mile round trip in dead of winter) weather warms to the point that dealer can’t test any more. I gave up, said I really wanted a diesel anyway…….
LESSON LEARNED: Get it documented, in writing, that this problem exists before the warranty expires. The only way to do that is to take it to the dealer so he can troubleshoot for an hour or so. Insure a complete and thorough description of problem (short cycle, repetitive surging under XXXXX conditions, how often) is written on the work ticket. Get and save a copy of that ticket.
Sorry for writing a novel-----hope Deere runs down this issue.

 

[renoel]

Hello,
Did this thread end here or was the results posted ? I'm having this problem with my X485 and would like to try to fix the problem myself; the warranty is expired.

Richard

 

[brs]

I had same issue. Backfire, surge, and engine would sart to run hot and fall down on 1 cylinder. My fuel pump (Electic in the tank) was making some wierd noises, so I pulled that. Found that they have updated this pump because of pickup issues and my problem was I was not getting consistant pressure to the fuel regulator due to a bad pump. $200.00 dollar ticket here.

 

[sunnyside360]

I had same issue. Backfire, surge, and engine would sart to run hot and fall down on 1 cylinder. My fuel pump (Electic in the tank) was making some wierd noises, so I pulled that. Found that they have updated this pump because of pickup issues and my problem was I was not getting consistant pressure to the fuel regulator due to a bad pump. $200.00 dollar ticket here.

I got an X485 shortly after JD came out with the X-series. There was a recall to replace the fuel pump even though I did not have any problems. Ran the unit a couple more years w/o any issues and traded for 3720.
I've heard gasoline with higher amounts of ethanol can cause problems when warm.

 

[renoel]

Thanks to both of you for your follow-ups. I apologize for not responding earlier with what resolved my problem ... As it turns out (I'm embarrassed to say), the filter screen behind the radiator had become completely clogged so very little air was getting through. This of course caused the engine to run hot. As you may have noted in other posts on this type of problem, the X-series engines are sensitive to heat and respond as described in this thread when they heat up. Since I found this filter screen - and which clearly I would have been aware of had I read the owner's manual more closely - I've been 'relgious' about keeping it clean and have not had a problem since.

Thanks again ...

Richard