# Deere Compact Utility Tractor Engine Combustion Noise



## Live Oak (Dec 22, 2003)

This subject may have come up in the past but this may be a good reminder for those of you with Yanmar engines in your John Deere CUT's. For some (myself included) the combustion noise or combustion knock (if you will) can be very irritating for the operator, especially when operating the tractor for long periods of time. I personally use a good pair of ear muff type hearing protectors but you can improve combustion noise level other ways too. 

Injection timing can effect this noise but in this case unless someone has been working or adjusting the pump timing, I would assume it is set correctly. The combustion knock in some cases can be related to poor quality or low cetane fuel. (not likley but sometimes the case if using fuel that has been setting for a long time) 

The minimum cetane rating for diesel fuel in the States is supposed to be 40. In this case the combustion knock can be reduced or minimized by the addition of a cetane rating level raising diesel fuel additive. Cetane rating of diesel fuel pertains to the delay of combustion upon completion of the ignition compression cycle. Lower cetane level fuels delay ignition longer; higher less delay and less noise. 

The most you can reasonably expect to raise the cetane level in most fuels is around 6 points but this can make a noticable difference depending on the quality of the fuel it is added to. Mind you, no miracle claims here; just a reasonable improvement in some cases. It is a good idea to use a good fuel additive as it is cheap insurance maintaining the fuel system as a good fuel additive will:


1. improve cetane rating (minimum should be 40 but higher is better)cetane rating is not like octane rating. It effects the delay of ignition of the fuel upon compression the less delay the better.

2. add detergents to aid cleaning the fuel system

3. stabilize the fuel (diesel is far more stabil than gas but cannot be stored for extended periods without deteriorating. A tractor or farm fuel source may sit for long periods.

4. enhance the lubricity of the fuel to ensure lubrication of injectors and pumps.

5. rust and corrosion protection from water or other contaminants that may get into fuel.

6. lowers gel/cloud point or winterizes fuel

7. provides de-ice protection in that it soluablizes water deposits mixed in with fuel with the fuel itself; allowing the water to pass through the system (still not good for it) with as little damage/problems as possible.

Some fuel additives that claim to raise cetane are Power Service (regular formula), John Deere Summer Formula, Howes, and Amalgamated Inc.

You may want to try one of these and see if you notice an improvement. In any case it is still a good maintenance practice to run a good diesel fuel additive all the time. 

In time you will come to either love or ignore the sound of a diesel at work.


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## MowHoward2210 (Nov 2, 2003)

Chief I am using the Power Service in the white bottle. It appears to be more of a winter formula, as it has the anti-gelling agents. I have read that it is ok to use this year 'round.

I looked for the PS in the Silver container, but all I found was the large size, and I was afraid it would sit on the shelf too long, as the only diesel I have is the fuel-sipping JD 2210.

I will alternate a non-treated tank and take sound readings btween the treated and untreated fuel. Should be interesting.


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## Live Oak (Dec 22, 2003)

I currently use Power Service in the silver bottle. I have noticed modest improvement in engine noise when I mix it at the full dose level to raise cetane 6 points. Nothing miraculous but a nice noticable improvemtent. Also makes an even more noticable improvement in the Cummins as well. I still use the muffs too. I spend too much time in the seat not to wear them. It would be VERY interesting to see what your results are. Another diesel fuel additive that a lot of guys over on TDR praise highly is Stanadyen Performance Formula. They used to make John Deere's fuel additive.


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## MowHoward2210 (Nov 2, 2003)

I have taken some dB readings on my 2210 that was running on a tank of treated diesel. I know I should wait to post results after the untreated tank is recorded (and I will), but I am posting now to reiterate a point.

I made readings at startup (2300 RPM) and at 5 minutes (2300 RPM) in a 30 X 45 polebarn. I always warm up the diesel before moving the tractor. The results seemed out of wack once I got home, so I wont post them. I will run them again before I put untreated diesel in the tank, and will also try to guage the cetane level increase per what is on the PS bottle that I don't have access to at this moment.

These figures were obtained outdoors "A" weighted and "C" weighted. (A / C)

dB @ Full Throttle - 3250 RPM 93 / 87
dB w/MMM engaged - 2900 RPM 96/89
db @ FT w/MMM engaged - 3200 RPM 100 / 97 

For what it is worth, I am just assuming a 50 RPM
drop w/the MMM engaged at Full Throttle. 2900 is the RPM that puts the Mid-PTO at 540 RPM, and that is the recommended speed for the mower.

The point (Chief's point) I want to reiterate is the need for hearing protection. I wear Craftsman "ear muffs" hearing protection. They are yellow and labeled at Peltor, FWIW.

We only have one set of ears, and this dumb*ss spent a lot of time 4" from a Jensen Triax speaker or the like, blasting 40w (a lot back then) of distorted Rock and Roll to the back of my head, so I'm sure I got a head start on hearing loss. I'm sure lots of us 30 to ? year old members have experienced all sorts of noises in our occupations that contribute. Why make it worse?


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## Live Oak (Dec 22, 2003)

I think your 2210 has an indirect injection Yanmar diesel? They are actually supposed to run quieter than a direct injection diesel. If you are pushing 100 dB, I can't imagain how much noise my 4410 is putting out with the MMM engaged at 2600 rpm! I know it is very irritating and even somewhat painful. The Stihl ear muffs work well and knock down the noise level to a comfortable level. They are made by Peltor. I think they cut the noise level 25dB. Now I know why my head hurt so much after mowing for 5 hours with no ear muffs when I first got the tractor.   That is VERY unhealthy.


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## MowHoward2210 (Nov 2, 2003)

Yes, Chief, it's an indirect injection Yanmar. What was weird was that it was louder at 2300 RPM after 5 minutes than at startup. I thought it would be just the opposite. I am holding a sound level meter upside down at arms link seated on the tractor and pointing it downward at the hood mounted fuel cap, thinking this would minimize reflection. With the meter upside down and my chicken-scratch notes, I might have screwed up the data, so I'll do it over. :nerd:


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