3720 Fuel Smoke

   / 3720 Fuel Smoke #1  

dkhntr04

Silver Member
Joined
Sep 26, 2010
Messages
169
Location
Northern MN
Tractor
Deere 3720 Cab
I just got my 2008 3720 yesterday and it puts out some greyish fuel smoke, the kind that burns your eyes. I can only see it in low light conditions when it is illuminated by artificial lights, but I can smell it, and it will cause the burning in me eyes when I am outside the cab and downwind.

I ran the tractor for 8 hours today and the smoke output seemed consistent all day long. The tractor was clean when I started and at the end of the day the left front of the loader frame had a considerable quantity of soot on it. The 59" blower that came with it also was black with soot on the left side from the previous owner.

This is not normal for most engine I have worked with, but I am just checking to see if this engine is known for running like this before I investigate further.
 
   / 3720 Fuel Smoke #2  
As far as the color goes, I experience the same thing as you in low light and late night. I have a verticle exhaust and work lights so i can see the grey smoke in the work lights. Cant see it during the day. My exhaust pipe has soot in it as well and it will smell if i climb out of the cab. My machine has less than 100 hors on it. Yours has been put to use and broken in. Everyone i know of that has the exhaust in the same location as yours has soot all over the loader frame. Im just gonna say this is normal buddy. This is my first diesel tractor but i run heavy equipment for a living and this is pretty much the nature of deisels engines. Is this your first deisel? Not being a wise crack. this is a serious question
 
   / 3720 Fuel Smoke
  • Thread Starter
#3  
Not my first diesel by far! I work as a farm mechanic and do everything from light bulbs to engine overhauls. I know enough to know that different engines may have different quirks. Some smoke like this, some don't. That's what I am trying to find out, if this engine is known for acrid fuel smoke.

I don't have much experience with small diesels, I operate and work on stuff in the 8-14 liter range most of the time. The Kubota B2400 and the McCormick I just sold didn't put out any smoke like this unless they were cold. The Mitsubishi in the McCormick put less soot on the FEL in 50 hours than this 3720 did in a day.
 
   / 3720 Fuel Smoke #4  
ok. well im just one guy and as i said, this is my first deisel tractor and i work with mainly larger diesels. Im thinking all is good since i have seen nothing but soot issues on the front end loader on the these machines and i experience most of what you say granted i have an exhaust stack throught the hood. Surely you will get some more responses to shed some light on this tonight or tomorrow
 
   / 3720 Fuel Smoke #5  
My 3720 isn't as clean as some other compact diesels I've had in the past. It's mainly an issue when operator at a lower rpm. If I'm working the engine a little the smoke is less. But at idle it seems to burn dirty. My 4720 was louder but not as much smoke. My previous three New Holland TC40D and DA produced very little smoke. But my 3720 has a noticeable smoke.
 
   / 3720 Fuel Smoke #6  
The diesels I've owned that had exhaust that burned my eyes usually had a cold water temp issue. Not familiar with your particular tractor, but if it does not have a water temp gauge, you might want to confirm that the thermostat is not opening to soon.
 
   / 3720 Fuel Smoke #7  
The issue is a combination of EPA mandates and the Yanmar engine itself. The normally aspirated 3320 has ~32hp, the turbo 3520 has ~37, and the intercooled 3720 has ~44. The harder a diesel works - within governor limitations - the less it will "smoke". Put a 3320 alongside a 3720 doing the exact same work, and you'll see fewer particulates in the 3720 exhaust. Through 2013 these engine only have to meet EPA T3 mandates. More strict mandates starting in 2014 (IT4) will require the use of particulate filters. Once that happens, you can actually run your finger inside the exhaust tip - and it will come out clean.

//greg//
 
   / 3720 Fuel Smoke #8  
The issue is a combination of EPA mandates and the Yanmar engine itself. The normally aspirated 3320 has ~32hp, the turbo 3520 has ~37, and the intercooled 3720 has ~44. The harder a diesel works - within governor limitations - the less it will "smoke". Put a 3320 alongside a 3720 doing the exact same work, and you'll see fewer particulates in the 3720 exhaust. Through 2013 these engine only have to meet EPA T3 mandates. More strict mandates starting in 2014 (IT4) will require the use of particulate filters. Once that happens, you can actually run your finger inside the exhaust tip - and it will come out clean.
//greg//

the 3720 should smoke more(comparatively) since it is higher hp and doing the same work as the 3320 by what you are saying since it is using LESS of its power potential..
the problem with that theory is the the 3720 is turbocharged AND intercooled and has LESS displacement than the 3320 so it could smoke more or less and still be normal.
 
   / 3720 Fuel Smoke #9  
This is not an issue unique to the 3720. I have had two of them and have also had a 4310 prior. All of them had the left lower exit exhaust and they all would about choke me when the weather was cold or in tight confines with a strong odor of diesel fuel. They also would all leave a sooty deposit on the left lower hood/side panel and on the loader arm on that side. I suspect the smell came from the fact that the exhaust fumes would hover low around the left side of the machine when cooler and when moving forward the operator would basically be driving through them. I currently have a 2320 and rarely, if ever, do I encounter this problem. The difference: one is a directed injected and the other an indirect injected diesel. Having operated a 3320, 3520, 2 3720's and a 2720 in addition to the machine I have now I can say I have never had a direct-injected diesel that did not seem to produce more fumes and more soot. Though some are more than others, I would say my experience is that this is normal, but aggravating.

John M
 
   / 3720 Fuel Smoke #10  
the 3720 should smoke more(comparatively) since it is higher hp and doing the same work as the 3320 .
Pretty sure that's what I said. And no, all three use the same basic block and 90mm stroke. The difference is that the 3320 has a 88mm bore giving it a 1.64l displacement. The other two have an 84mm bore, giving them 1.5 liter displacement. But that's immaterial, 3320 hp and torque are still lower than the other two. So carrying the same weight and doing the same work, the 3320 is going to work harder and smoke comparatively less (assuming operators follow prescribed throttle settings).

//greg//
 
 
Top