155 Sluge from exhaust Why?

[Yanmar155]

I repainted the green Yanmar to an International paint code. Motor runs just fine but I am getting black sludge from the exhaust. New injectors and pump looks clean and fine.

 

[bmaverick]

I repainted the green Yanmar to an International paint code. Motor runs just fine but I am getting black sludge from the exhaust. New injectors and pump looks clean and fine.View attachment 1843904

Maybe hydraulic hose spitting ?

 

[ponytug]

@yanmwar155 Welcome! Where are you located? You might want to update your profile.

My bet would be not working the diesel hard enough and getting what is called wet stacking.

Wet stacking - Wikipedia

en.wikipedia.org

After you rule out fuel leaking into the exhaust, generally increasingly graded exercise (workload) on the tractor will burn it off. (Don't forget to check for fuel in the oil before working the tractor hard, as some wet stacking causes can dilute the oil.)

All the best,

Peter

 

[zzvyb6]

Mine does it after a heavy rain even though the stack's exhaust flow is sideways at the top. Carbon buildup is washed into clumps, then spit out.

 

[Yanmar155]

@yanmwar155 Welcome! Where are you located? You might want to update your profile.

My bet would be not working the diesel hard enough and getting what is called wet stacking.

Wet stacking - Wikipedia

en.wikipedia.org

After you rule out fuel leaking into the exhaust, generally increasingly graded exercise (workload) on the tractor will burn it off. (Don't forget to check for fuel in the oil before working the tractor hard, as some wet stacking causes can dilute the oil.)

All the best,

Peter

I have been monitoring the engine oil and it looks fine. I have no temp guage but can use a hand held temp reader.
Also, I took the exhaust off and noticed the sludge coming out of the back cylinder.

 

[careyo63]

Does the muffler have a lid on it to prevent Rain from getting in it or Smell like Diesel fuel. I would be checking your fluid levels and see if your low on anything.
I would get oily carbon bombs on my hood . I pulled the Exhaust and soaked it in gas then blew it all out with the Air compressor. It quit doing it but my lid will get a carbon build up on it that I clean it off every few months and guess that's what it was coming from over the decades. Thin liquid looking?

 

[bmaverick]

I have been monitoring the engine oil and it looks fine. I have no temp guage but can use a hand held temp reader.
Also, I took the exhaust off and noticed the sludge coming out of the back cylinder.

What grade oil are you running? These Yanmar engines do not like 15W40. It's a bit too thick. It retains heat longer in the engine. Yanmar and Deere mention to use 10W30 summer, hot summers straight SAE30 and winter 5W30.

Additionally, for any diesel engine, it is ideal to use the TALLEST possible fitting filter you can find. Those with diesel trucks understand the principles behind this important need. Most filters today are finer micro, thus the flow supply of oil is reduced. To regain the flow, a taller filter is best. More filter surface area is the key.

Keep the engine idle times to less than 10mins. I try to keep it at 5mins max.

 

[YanmarFever]

Its called diesel slobber, did you leave the tractor out in the rain?

 

[winston1]

Noting one cylinder might be causing this you might want to consider loosening injector lines one at a time and see if problem cylinder is different. Carefull with high pressure if doing it. Could possibly be a bad injector. Worth looking into.

 

[4get gto]

Kind of agree with winston above. You might want to check into that cylinder in question. Does it clear up after running a bit or does it keep spitting it out. ? Does the cylinder in question get as hot when running ? Should be able to put temperature gun on each individual cylinders to check OR you might be able feel the difference. Be extra careful doing it this old recheck way...normally they don't get as hot as gas motor would..