We have three John Deere tractors. Two 2006 model 6615's and one 2001 model 6405. The 6405 has started blowing large amounts of blue white (unburnt fuel) smoke when going down hill under partial throttle. Now one of the 6615's is beginning to to the same. Pulling the throttle back to idle stops the smoke. I'm kind of suspecting leaky injectors. But I'm not a diesel mechanic. Some of our other older tractors are also beginning to smoke. Should we be adding two stroke oil to their fuel due to the ULSD. Any input would be appreciated.

Hmmm... I got another great forum that is specialize in Tractor and such... www.tractorfarmandfamily.com The owner is a member here LiveOak or (TFF Admin)

Thanks for the plug Mike! We would love to hear about the issues you having on TFF but before I can reply with a more accurate answer, the duty cylce or use these tractors are put to would be helpful in diagnosing the problem. Smoke can be caused by a number of issues. Many times on these tractors that don't get a lot of a long, high power duty cycle and/or spend a lot of time idling tend to smoke a good bit until run for a hard days work.

What pople don't realize is that the injectors on newer equipment no matter what it is has just as finicky of fuel systems and requirements as over the road vehicles anymore. Frequent fuel filter changes and clean fuel are still required just like any other engine. Problem I see is farmers with the old rusty fuel tanks at the farm and in the bed of the truck ect that have never been cleaned and then they wonder why they go through injectors and pumps on their new tractors.......... Or I have seen them pull the fuel nozzle out that was full of dirt and just pump it in the tank without wiping it out and the same with dirt around the fuel filler neck. Some people just don't care until its effects show up and then complain about the product rather than their practices.

Thanks for the plug Mike! We would love to hear about the issues you having on TFF but before I can reply with a more accurate answer, the duty cylce or use these tractors are put to would be helpful in diagnosing the problem. Smoke can be caused by a number of issues. Many times on these tractors that don't get a lot of a long, high power duty cycle and/or spend a lot of time idling tend to smoke a good bit until run for a hard days work.

Checked out your site...looks good, but didn't see much that looked like "in depth diesel guru-age" like this site. About these tractors, they are all full time working farm tractors. The 6405 is probably the hardest working tractor on the farm. Its the mid sized all around tractor. It pulls in most of the loads at harvest time (Now), and good old western PA has plenty of hills to make it work hard. It also does most of the planting, brush hogging, and any other tasks that don't require the 100 hp tractors. It gets plenty of chances to burn out the carbon, but it consistently smokes on down grades. Whats coming out of the stack is plain old raw fuel, same as you get on a frigid morning. Thats why I think fuel is leaking from the injectors at low pressure when it shouldn't be entering the cylinder at all. But thats just a theory.

Checked out your site...looks good, but didn't see much that looked like "in depth diesel guru-age" like this site. About these tractors, they are all full time working farm tractors. The 6405 is probably the hardest working tractor on the farm. Its the mid sized all around tractor. It pulls in most of the loads at harvest time (Now), and good old western PA has plenty of hills to make it work hard. It also does most of the planting, brush hogging, and any other tasks that don't require the 100 hp tractors. It gets plenty of chances to burn out the carbon, but it consistently smokes on down grades. Whats coming out of the stack is plain old raw fuel, same as you get on a frigid morning. Thats why I think fuel is leaking from the injectors at low pressure when it shouldn't be entering the cylinder at all. But thats just a theory.

Call a deere dealer and ask for the service department then ask the service guy about it, he will be able to give you a TON of information they see problems just like yours everyday and could at least give you a clue. If they say "just bring it in" say thanks and try another dealer in the phone book. Trust me, you will find one with a service or parts guy that will talk to you and be honest.

I have a friend with a 5525 and he has the same issue with it. It was worrysome for him. Finally JD (West Central in Somerset) came out and replaced the fuel lines. It appears from what the mechanic said that Deere bought some cheezy cheap fuel line and they draw air badly into the injection pump. I would think this would be a real good place to start. Good fuel line is a whole lot less expensive than a service call. Regardless if it is the problem or not, the fuel lines should be replaced. The ones from the tank to the transfer pump.This fellows tractor was a 2004 or 2005 model so the problem has been around for a while. His would also blow white smoke at times.