Heavy black smoke, 6V71 non turbo

[Hallback]

We have a 6v71 in our West Coast yarder and it blows an extreme amount of black smoke. We put a new air filter on it and it still has not alleviated the problem. Do these usually have injector issues where they could be over fueling? It is so bad that it has covered our processor in soot within 200 hours of running.

 

[Bluox]

Need more info , under load , picking up load ect. just started done all along ? Check air filter intake.
could be injectors.
Bob

 

[Birken Vogt]

Somebody correct me if I am wrong but I think in truck engines the horsepower/fuel volume was set by injector part number. Larger injectors=more fuel possible. So maybe some clown along the way decided to "increase power" by putting in oversize injectors. Check the part number, should be pretty easy to figure this one yes or no.

 

[Hallback]

It is under load. Only one when yarding a turn in does it do it.

 

[old-iron-habit]

Not sure where it sets on a V6-71 but if the return line restrictor is wrong sized for the injectors or partially plugged it could contribute to black smoke. On a inline engine they are the 90 degree brass fitting coming out of the head on the return
fuel line. Is this condition new in the last 200 hrs you ran it or is this a newly acquired machine that came with the black smoke problem?

 

[kshansen]

Started with the questions/suggestions below and almost forgot the most important questions! Is this something new or has it done it for as long as you have been around it. Next important question is other than the new air filter has anyone done any work on this engine? To me these are the most important things to know before trying to diagnosis a problem!

Now back to the other questions in no particular order just as they come to mind:

You say it's Non-Turbo so one idea would be to remove exhaust manifolds and run it to see if the smoke is coming out of all exhausts the same black snootiness. Just be sure to wear hearing protection!

Also check for restriction in the exhaust side of things, if exhaust can't get out fresh air for combustion can't get in!

Have you checked to see if there is anything covering the screen on top of the blower? Did someone stick a rag in intake while changing air filter and forget to remove it?

Can you take the top off the blower and see that the emergency shut down is fully open when latched? Do the rotors of the blower look nice and clean or are they coated with black greasy gunk?

Other have made good suggestions and I'm sure more will have ideas as well.

May even help if you could post a short video or even a picture to let us see more or less first hand what the exhaust actually looks like. A little puff of smoke when first getting into it might be normal but if it looks like an old steam engine pulling a grade not so normal!

 

[Hallback]

It is like an old coal train when it is pulling a turn. It is done this ever since we got the machine and we have a couple hundred hours on it now. Thanks for the tip on checking the blower as I had forgot about the emergency shutdown on there.

 

[RZucker]

Another thing to check is for loose air box covers or blown out cover gaskets. seen that a time or 2.
Another thought is what's the oil consumption? I have seen leaking piston pin retainers make black smoke on a hard pull.

 

[Hallback]

That's what gets me, it is not using oil and it is very light on the fuel usage also.

 

[Birken Vogt]

Well don't let it continue because all that soot is basically like dust tearing up the innards of the motor. A puff here and there is OK but not all the time.

 

[kshansen]

Another thing to check is for loose air box covers or blown out cover gaskets. seen that a time or 2.
Another thought is what's the oil consumption? I have seen leaking piston pin retainers make black smoke on a hard pull.

Air box cover leaks!
That's a good one I forgot about! Loose or leaking airbox cover(s) would effectively be the same as a bad turbo on a turbo engine, low boost so not enough air to burn the fuel that the injectors are pushing out under load.

If you have access to a manometer or pressure gauge that reads in inches of mercury you can attach it to one of the airbox drains, those pipes that hang down on the side of the engine and tend to drip oil! Under full load at 2,100 RPM you should have between 5 and 8.2 inches of mercury pressure on those tubes. That is only equal to 2.5 to 4 psi so need a good gauge to read that low accurately.

Might not have anything to due with the smoke but what are you using for oil? Detroits like straight weight 40 or 50 SAE oil with the right additives. Somebody can probably point to a long thread here on that subject!

 

[Former Wrench]

Here are a couple of ideas that sort of have been mentioned. Injectors should be 65 MM or less. The 70 and 75 are for turbo engines providing more air. Faulty blower drive seals could have caused oil slime to plug the blower screen, losing air flow. A faulty tune up. If the valves are not set right, you're not in time; same with injector heights; should be 1.460. Crushed or damaged air cleaner or air cleaner housing.

 

[Bluox]

Have some one do a overhead on the engine.
Bob

 

[crane operator]

I'm thinking emergency shut down like khansen mentioned, or blower seals etc.

My 6-71 inline with no turbo doesn't black smoke at all, and I'm working the snot out of it dragging around 80,000 of crane.

Mine will tend to burn off slobbered oil that wet stacks in the exhaust manifold when I'm doing too much idling on a jobsite with the crane. Usually about 3 miles down the road it gets the exhaust manifold warm enough to burn it out. It doesn't use much oil, but it will smoke that out when it finally gets hot enough.

If he's sitting there quite a bit between turns, and then has a hard pull, it may warm it up enough to burn that oil out.

If yours is wet stacking you'll see it around the exhaust manifolds and piping.

 

[Hallback]

Yeah I haven't noticed any of the wet stacking or blubbering. It is usually about 2 minutes between turns Max.

 

[Junkyard]

How did I miss a Detroit thread? Shame on me. Worst thing is I can’t think of anything to add!

That sound you hear is my head banging the table.....

Good luck. I’ll fly up and sort it out for ya if you want! Haha

 

[RZucker]

Here are a couple of ideas that sort of have been mentioned. Injectors should be 65 MM or less. The 70 and 75 are for turbo engines providing more air. Faulty blower drive seals could have caused oil slime to plug the blower screen, losing air flow. A faulty tune up. If the valves are not set right, you're not in time; same with injector heights; should be 1.460. Crushed or damaged air cleaner or air cleaner housing.

1.460 is no Bueno in a natural aspirated 71 series with advanced cam timing (and most are), 1.484 is the proper timing pin for them. 1.460 in an engine with advanced timing will lead to broken top rings and missing piston parts. Usually the top ring land. Check the rocker cover tag before tuning one of these engines.

 

[Birken Vogt]

1.460 is no Bueno in a natural aspirated 71 series with advanced cam timing (and most are), 1.484 is the proper timing pin for them. 1.460 in an engine with advanced timing will lead to broken top rings and missing piston parts. Usually the top ring land. Check the rocker cover tag before tuning one of these engines.

Yes but no telling what Billy Bob has been in there and done before you got to it....

Any way to tell how the cam may be timed without pulling the engine apart? Dial indicator and degrees but is that info published anywhere?

 

[RZucker]

Yes but no telling what Billy Bob has been in there and done before you got to it....

Any way to tell how the cam may be timed without pulling the engine apart? Dial indicator and degrees but is that info published anywhere?

There is a procedure in the service manual to check cam timing. Don't remember it off the top of my head, but it does tell you where the cams are set. And yes, I have seen some strange combinations from engine swaps.

 

[Truck Shop]

Yes but no telling what Billy Bob has been in there and done before you got to it....

Any way to tell how the cam may be timed without pulling the engine apart? Dial indicator and degrees but is that info published anywhere?

It's not necessarily a Billy Bob but definitely a {whoodly dang} that one should worry about tinkering around under valve covers.

Truck Shop