X495 throttle up "whump"

[ArkCivEngr]

X495 throttle up \"whump\"

A normal start-up on my X495 is a gradual throttling up, usually taking a minute to a minute and a half. It works out right because that's about how long it takes me to drive to where my trailer is, and most of my yards are further off than that.

I've noticed that if I try to throttle up more quickly than that, I get a dull "whump" sound from the engine. It's a muffled sound, and it also shakes the front end of the tractor a little, exactly like someone lightly kicking a tire.

This usually does not happen on a warm startup; only when I haven't operated it for more than a day.

Any ideas what's causing this? It gives me absolutely no problems other than this minor issue.

 

[awlchu]

Re: X495 throttle up \"whump\"

I have not noticed any unusual noises from my X595. I can throttle up immediately from cold start without a problem.

Did you make any changes to your tractor? new fuel, new filters, any disassembly (outside of maintenance)?

Any fuel leaks etc. ?

 

[ArkCivEngr]

Re: X495 throttle up \"whump\"

None of the changes you mentioned. I've changed the engine oil and filter, but this noise happened before that. The only other thing I've done is replace the back-plate on the transmission (the aluminum one that says "Tuff Torq"), and when I did that, I also changed out the transmission fluid and filter. But again, this sound has been around quite a bit before that happened.

I hauled 3 loads of brush off this evening, and watched it closely. Even after a 7-8 minute ride from the garage to the trailer to the work area, it still had the "whump" on throttle-up. I have a little puff of dark smoke on startup, but so does my Cummins and Kubota and most every other diesel I've ever seen, so that can't be an issue. There is no smoke that I've noticed when the "whump" happens, although white smoke is more difficult to see.

When you say you throttle up immediately, do you mean you just push from zero and go straight to full throttle, nothing gradual and no pausing? If you can do that with no noises, I'll probably at least ask my dealer about it.

 

[awlchu]

Re: X495 throttle up \"whump\"

To quantify, I can push my throttle up from idle to WOT within 1 sec and not have a problem (stalling or unusual noises).

This probably is a diesel thing...

At WOT this is one of the smoothest engines I've ever had.

 

[ArkCivEngr]

Re: X495 throttle up \"whump\"

I agree; it is a smooth one.

I hauled a few more loads today, and noticed that the sound is also accompanied at times by a little puff of white/gray smoke. It also seemed to do it less as the afternoon wore on; I presume because the engine was warmer.

I did my initial oil change at 33 hours instead of the recommended 50 (found the "break-in oil" thread a bit too late). I'm just wondering if this noise has anything to do with that.

 

[ArkCivEngr]

Re: X495 throttle up \"whump\"

This may be causing my problem: according to the owner's manual startup procedure, it says to go between 1/2 and FULL throttle before cranking. My normal starting point has been low idle or perhaps 1/4.

I guess I'll do as the manual says and put it at 1/2 or a shade above and see if that solves the problem. That just seems odd, though. Almost like it's too much, too quickly. /forums/images/graemlins/confused.gif