MX6000 noise after warm.

[beal13]

Hi, can anyone tell me what is making the sound about 5 seconds into this recording. This occurs about one to two minutes after starting and letting the tractor warm up, it doesn’t go away just gets drowned out at higher rpm’s. It’s on an MX6000, about 55 hours, all fluids and filters changed, and it doesn’t seem to affect performance. Thank you!

MX6000.m4a

drive.google.com

 

[mcmxi]

Hi, can anyone tell me what is making the sound about 5 seconds into this recording. This occurs about one to two minutes after starting and letting the tractor warm up, it doesn’t go away just gets drowned out at higher rpm’s. It’s on an MX6000, about 55 hours, all fluids and filters changed, and it doesn’t seem to affect performance. Thank you!

MX6000.m4a

drive.google.com

Are you applying the parking brake at any point during that audio clip? There's more noise transferred into the cab with the parking brake applied. Also, I've noticed that the bucket level indicator vibrates at a frequency that produces an annoying metallic tone.

 

[beal13]

Are you applying the parking brake at any point during that audio clip? There's more noise transferred into the cab with the parking brake applied. Also, I've noticed that the bucket level indicator vibrates at a frequency that produces an annoying metallic tone.

Hi, yes the parking break is on so I’ll have to try without, it’s not a cab model though. Sounds perfect for close to 2 minutes warming up from starting and then the sound starts. Thanks

 

[beal13]

Are you applying the parking brake at any point during that audio clip? There's more noise transferred into the cab with the parking brake applied. Also, I've noticed that the bucket level indicator vibrates at a frequency that produces an annoying metallic tone.

Just an update that the noise is present with or without the parking brake and we don’t have a bucket level indicator. It definitely appears to be engine related as it’s not present until the engine is warm and once it starts the only way to make it go away or maybe just appear to go away is having the throttle at the lowest setting.

 

[Matt Ellerbee]

My 6000 has had that rattle since I got it at 125 hrs. Has 240ish now. Put on headphones and turn it up.

Like you said, no performance issues here, oil is good and regens are consistent. I haven’t worried much about it.

 

[woodman55]

My L6060 does the same thing, and it is at low idle.

 

[mcmxi]

I'd forgotten that my MX has the same "feature". I don't know if this will work but I recorded my MX6000 warming up from cold with all accessories off. It took about 3 minutes with the engine running at around 1,500 rpm before the additional sound could be heard. This audio clip is 30 seconds long and the sound "kicks in" at 21 seconds.

MX6000 Cold Start.mp3

drive.google.com

I have close to 200 hours on my MX now (bought new), and had 110 hours or so on the open station MX6000 that I sold. I don't remember if that one had the same "feature", but it was a smooth running beast, as is this one. It would be interesting to know what is activating and making that sound. It could be part of the exhaust system, the HST pump, and hopefully @whitetiger or @North Idaho Wolfman can chime in and explain the mystery.

 

[mcmxi]

@beal13, I changed the sharing permissions to "anyone with the link" so you should be able to listen to the audio file now.

 

[beal13]

I'd forgotten that my MX has the same "feature". I don't know if this will work but I recorded my MX6000 warming up from cold with all accessories off. It took about 3 minutes with the engine running at around 1,500 rpm before the additional sound could be heard. This audio clip is 30 seconds long and the sound "kicks in" at 21 seconds.

https://drive.google.com/file/d/1xnKZttq_07FLN-3xHu1S_tv-b1xQ_Jux/view?usp=drive_link

I have close to 200 hours on my MX now (bought new), and had 110 hours or so on the open station MX6000 that I sold. I don't remember if that one had the same "feature", but it was a smooth running beast, as is this one. It would be interesting to know what is activating and making that sound. It could be part of the exhaust system, the HST pump, and hopefully @whitetiger or @North Idaho Wolfman can chime in and explain the mystery.

Thank you! I believe that’s definitely the same. I won’t stress over it anymore.

 

[mcmxi]

Thank you! I believe that’s definitely the same. I won’t stress over it anymore.

I would like to know the "why" if someone cares to enlighten us.

 

[mcmxi]

I'm wondering if the change in sound has something to do with the EGR valve. The valve is closed when the engine is cold, but as it warms up the valve opens to allow exhaust gas to pass through the EGR cooler and into the intake. Hmmm ....

I'm trying to remember if the M6060 does this too. I'll have to check that out tomorrow.

 

[woodman55]

I am wondering if a couple of the injectors are turning off, to make the engine warm up faster ? It is a common feature with electronically controlled engines.

 

[fried1765]

Hi, yes the parking break is on so I’ll have to try without, it’s not a cab model though. Sounds perfect for close to 2 minutes warming up from starting and then the sound starts. Thanks

Warranty?
Call the dealer!
Have him pick it up!

 

[mcmxi]

I am wondering if a couple of the injectors are turning off, to make the engine warm up faster ? It is a common feature with electronically controlled engines.

I looked through the WSM and have yet to find any explanation as to the cold start process but I like the way you're thinking.

Many years ago when I bought my first diesel truck, a 2002 F350 Crew Cab DRW shown below, I had no idea that the injectors would shut off when letting off on the accelerator. I remember my first drive from the docks in Honolulu to my house in Aiea, and a particular down grade when the engine appeared to die, but the silence was just the injectors shutting off.

There's no compression breaking with those trucks, so I ended up tapping into the EBPV (exhaust back pressure valve) circuit which is used for warm up, and adding a switch and LED so that I could activate the valve on long down grades such as the Likelike Hwy. It made a huge difference to how much braking was required. Great memories of this 6-speed manual truck. It was an XLT 7.3L model and cost $34k in 2001.

 

[loggin]

I am wondering if a couple of the injectors are turning off, to make the engine warm up faster ? It is a common feature with electronically controlled engines.

Umm.. I am trying to understand this. Perhaps you could explain how turning off an injector would help to warm up an engine? Also I think you would definitely notice if an injector turned off at idle on a 4 cylinder engine. Wouldn't it be running really rough..?

Always trying to learn!

 

[woodman55]

Umm.. I am trying to understand this. Perhaps you could explain how turning off an injector would help to warm up an engine? Also I think you would definitely notice if an injector turned off at idle on a 4 cylinder engine. Wouldn't it be running really rough..?

Always trying to learn!

The other cyls work harder to keep the engine running, this raises the cyl temps, which warms the engine faster. The engine does run rougher, which is the change in sound we are hearing.

 

[mcmxi]

I did a cold start test on the M6060 this morning and recorded the engine sound for 7 minutes. I think at around 1.45 minutes after starting there's a change in sound but it's very subtle compared to the MX6000. The audio file in the link is 30 seconds long and the change in sound can be heard at around 20 seconds. The M6060 warms up way faster than the MX6000 if the coolant temperature gauges are anything to go by.

I changed the file of the MX to an MP3 and added here for ease of comparison.

M6060 Cold Start.mp3

drive.google.com

MX6000 Cold Start.mp3

drive.google.com