MF 2660 Perkins Smoke

[JWR]

My MF 2660 has about 550 hrs or slightly less on it. 2010 model bought in April 2011. Never ever a minute's trouble with that Perkins. Probably the most reliable thing about the tractor... Anyway on 11/27/22 at about 38 degrees outside air temp I started it up with no problem and went about using it for 1/2 hr grapple working some limbs. Warmed into the 50's while working. Then I moved to a different field to do final bush hogging of meadows before winter. That's when the smoke started. Heavily smoking blue/white smoke for several hundred feet of downhill travel. Could find nothing wrong. Oil at full mark. Temp normal. Running smooth. No warning lights on or blinking or momentary. Same as always except for the smoke. When smoking it was heavy not just a hint but a LOT of smoke. Nothing like I saw one time when a diesel was burning crankcase oil (black cloud about like a plane crash) -- not at all similar. During the next 90 minutes of work cutting heavy wet grass and weeds everything ran totally normal. No issues but once in a while a period of smoking. ALWAYS GOING DOWNHILL or just after downhill travel. Never smoked going uphill.

Background: The fuel tank was down low to probably 4 or 5 gal when I added one 5 gal can of red dyed off-road diesel the night before the smoking started. That fuel was from a high volume regional supplier at their terminal and had sat in the can about 1 month. The can was "clean" in that it is never used for anything but diesel and kept closed in a garage. Next morning, the day of the smoking, I added one more fresh can of fuel (not off-road, just purchased from a truck stop that morning) which brought the gauge up to a little more than half full.

Note also that I had my 2660 modified in 2011 when new because the #$%^& thing would not climb a 45% slope with 1/3 of a tank of fuel (!) Stalled. Starved for fuel. The dealer put a T with stop valves in the legs such that one pickup was in the back and one in the front of the tank. That solved the hill-climb starvation of fuel issue.
[I was cussing mad about that and a dozen other issues at the time in a brand new tractor right off the showroom floor. Another long story.]

Now, all that said, my theory is that this smoking is/was a fuel issue. It only happened going downhill or just long enough after downhill for the fuel to get picked up and in to the injectors. It cannot be crankcase oil related (burning that would be coal black smoke.) I know of no path for hydraulic oil to get into the combustion. Total cumulative smoking time out of a 2 to 2.5 hour running time I estimate was a few minutes, not just a few seconds.

What say you world of experienced diesel operators ? Why was is it smoking ? [I say "was" because after a couple hours operation there was no more heavy smoking but 1 or 2 times I did notice a very light smoking for a few seconds... obviously not staring at the exhaust for 2 hours. When it was smoking heavily it got your attention without looking at the exhaust.]

 

[lpakiz]

Here's a Wild, Wild WAG-- could you have a failed valve stem seal (or a crack or some other means) near the front of the engine, or in a location where run-off valve train lube oil could pool and/or run into the intake passages in the head, thereby entering the combustion chamber? Altho smoke from burning lube-oil would generally be more blue than black.
If you throttled down to idle during one of these episodes, do you think all cylinders are excessively smoking equally, or ate there distinct puffs, indicating only one cylinder is the culprit?
Did you or could you notice an increase in power, coming from the extra "fuel"? On older engines (before controlled emissions) there was a "blow-by" tube under the engine to vent crankcase fumes out to atmosphere. It would be interesting to see if the amount of blow-by "fog" decreased during these episodes.
Could engine oil pool in the air intake system somehow to feed oil or fumes into the engine? I'm thinking of the old EGR systems on gas engines. There are engines that have a system to "scavenge" crankcase fumes and route them to the air intake so they burn (as fuel) instead of venting them to the atmosphere.

I suppose if you burned enough engine oil, it would show up as low oil on the dipstick.

The old 2-cycle Detroit Diesels would actually "run away" when seals in the blower or turbo would fail and the engine would suck in and run on engine oil. If I recall correctly, they were equipped with an emergency flapper that could be deployed to block the air intake, to snub the engine in such a situation. If left unchecked, the engine would over-rev to the point of self-destruction, IE--blow up!

 

[MF243RedTop]

I say it just sucked some air into the system through one pickup or the other since you mentioned the T on the pickup lines. Once the air was cleared through the system the engine went back to operating normally.

Sounds like a poorly designed fuel tank without enough slope on the bottom to take hills and slopes into account.

 

[thepumpguysc]

If your engine intake system has a “THERMO-START” ..
Check it for proper operation.
Unhook the fuel feed line and cap it..
Good luck

 

[JWR]

If your engine intake system has a “THERMO-START” ..
Check it for proper operation.
Unhook the fuel feed line and cap it..
Good luck

Do not know what that is. I will need to look into it. Hold that thought...

 

[JWR]

I say it just sucked some air into the system through one pickup or the other since you mentioned the T on the pickup lines. Once the air was cleared through the system the engine went back to operating normally.

Sounds like a poorly designed fuel tank without enough slope on the bottom to take hills and slopes into account.

Would sucking air instead of fuel produce blueish white smoke ? There was no effect on power that I could detect, though going down hill it would not show. A few bursts of smoke did happen just after a downhill but I never felt any interruption of power output. I would have felt it then after the downhill.

 

[thepumpguysc]

If it does have that system.. it’ll be screwed into the intake manifold where the rubber ends and aluminum starts..
There will be a single wire and a tube for the fuel to enter the intake.

 

[JWR]

Here's a Wild, Wild WAG-- could you have a failed valve stem seal (or a crack or some other means) near the front of the engine, or in a location where run-off valve train lube oil could pool and/or run into the intake passages in the head, thereby entering the combustion chamber? Altho smoke from burning lube-oil would generally be more blue than black.

No, lube oil in a diesel, if burned, puts out some really black smoke, not blueish.

If you throttled down to idle during one of these episodes, do you think all cylinders are excessively smoking equally, or ate there distinct puffs, indicating only one cylinder is the culprit?

No distinct puffs. It ran the entire time like nothing ever happened. I did throttle down to idle AND up to higher than normal operating rpm during the smoking and could see no change. No missing, no stumble, no change in the smoking.

Did you or could you notice an increase in power, coming from the extra "fuel"? On older engines (before controlled emissions) there was a "blow-by" tube under the engine to vent crankcase fumes out to atmosphere. It would be interesting to see if the amount of blow-by "fog" decreased during these episodes.

No. No change in power output.

Could engine oil pool in the air intake system somehow to feed oil or fumes into the engine? I'm thinking of the old EGR systems on gas engines. There are engines that have a system to "scavenge" crankcase fumes and route them to the air intake so they burn (as fuel) instead of venting them to the atmosphere.

Not sure about fumes but EGR systems on a VW diesel can put lube oil in the intake and the result is black smoke out the rear -- big time!

I suppose if you burned enough engine oil, it would show up as low oil on the dipstick.

No apparent engine oil usage. Checked it after this incident and had checked it a month ago. Right at the full mark, no change.

The old 2-cycle Detroit Diesels would actually "run away" when seals in the blower or turbo would fail and the engine would suck in and run on engine oil. If I recall correctly, they were equipped with an emergency flapper that could be deployed to block the air intake, to snub the engine in such a situation. If left unchecked, the engine would over-rev to the point of self-destruction, IE--blow up!

Amen to that ! Tell me about it! I had a VW diesel start sucking engine oil from the crankcase due to excessive blowby in it's old age. It fogged the entire highway with sooty black smoke for 1/4 mile until I finally figured out what was happening. Key would not shut it down of course and I had to put it in high gear and use the brakes to stall the engine. Thank goodness it was a stick and not automatic! That happens you will never forget it. Using air intake blockage is about the ONLY solution if it had been an automatic. And that never occurred to me so I would have lost the engine if it had been automatic.

 

[thepumpguysc]

Lol.!!!! Run aways are funny.. it WASNT the FIRST TIME tho..
I love watching people freak out..
I’ve had the pleasure of watching SEVERAL.. & putting out most..

 

[MF243RedTop]

Would sucking air instead of fuel produce blueish white smoke ? There was no effect on power that I could detect, though going down hill it would not show. A few bursts of smoke did happen just after a downhill but I never felt any interruption of power output. I would have felt it then after the downhill.

Sourced from the web:

-Continuous “light” white smoke

To run correctly, a diesel engine needs precise timing of the injector pump and proper pressure. Any decrease in the pressure or delay in delivering the fuel to the combustion chamber will cause incomplete combustion, and you will have white smoke.

This is a steady stream of lighter white smoke. It can even be random but often “puff.” Some likely causes include,

A clogged fuel filter
Low pressure in the fuel pump (Air in the fuel)
Faulty or damaged injectors

Enough air to cause smoke but not enough to interrupt power.