HELP... smoke comming out of crankcase breather

[darylat8750ft]

Hi Guys,
My 4341 moved a lot of snow this winter. Good so far. Today I was grading with a double blade grader. I was coming uphill in 3H and the fuel control unit was wide open for 4 to 5 min. with the RPM vareing between 1500 (rarely usually it was above 1700) and 2100. It pulled down to 1500RPM and the gravel was getting deeper so I was just reaching for the clutch to shift down. It started ratteling like a Ford diesel pickup when it is cold. RPM / power dropped rapidly, I disengaged the clutch before it quit and pulled the throttle back. Now there is a lot of blow-by. A lot of smokey air coming out of the crankcase breather tube. If it was a elect. ignition engine I would say it had the timing to far advanced and it pre-ignited and put a hole in a piston, but I have very little experience with diesels. There were no bad mechanical sounds. So..... I won't know for sure until I pull the heads but any educated guesses would be appreciated. If the sleave is messed up is it possible to change a sleave in a home shop or is a big press nessassary?
Thanks,
Daryl in WY

 

[dave_peters]

Sounds like you may have a broken piston.
Cylinder liners are not hard to get out, best way is to make up a puller with a bit of threaded rod and some plate, buit if you have a copper drift they can be tapped up from the sump end with a hammer.
If the bore is not damaged you can buy pistons seperately, just clean up the bore with a hone or glazebuster and make sure there is no step at the top. if there is you can get a stepped compression ring from a re-ring set to make sure the ring doesn't hit the step, or get the step machined out.
On balance I would say , replace the piston and liner. In UK at least, they are not killingly expensive
Dave

 

[darylat8750ft]

Thanks Dave,
That's what it sounds like to me. I'll go out and pull the heads off now. I hope I don't have to change the sleeve. Should know in a few hours.
Should these things have an ignition "rattle" after they are warmed up? Could this have been caused by the fuel injection having too much advance? Did I just "lug" it too long?
Thanks,
Daryl in WY, USA

 

[alan]

One or more of the pistons have "picked up" & siezed the piston rings. Replace damaged pistons & thier liners in matched graded pairs. (A grade piston with A grade liner, B grade piston with B grade liner or C grade piston with C grade liner) Do not mix different grade pistons & liners

 

[darylat8750ft]

Thanks for the input guys,
I have the heads off. Nothing looks obviously bad. The number 3 cyl. looks "cleaner" than the other 3. There is a possible crack on the top of the piston but I didn't dare scratch at it with any hard, in case it wasn't. Tomorrow I will clean it up with rags and solvent and get a better look. Alan's view of seized rings makes sense to me. On first look the cyl. walls have nice cross hatch hone marks yet. Would seized rings mess up the cyl. walls? I guess I'll just have to pull all the pistons. I haven't had to use my ring compressor since my racing days. (One nice thing about race cars is that you break them before they get very dirty or rusty

Any comments on possible causes of this? Did I just lug it too long or is timing a possibility? It only has a little over 500 hours on it.

I live at 8700 feet (around 3000 meters, I think) elevation. More power is always useful. Are higher compression pistons available? If not, is milling the heads possible, and if so how much can I safely take off? I did check the intake and exhaust manifolds. The gaskets for both intake and exhaust are slightly smaller I.D. than the manifolds and ports in the heads. I will carefully match them up on reassembly and should pick up a little power.

Thanks for your knowledge and efforts.
Daryl in WY

 

[ixer0]

Hi

These engines normally "go for ever". Did it overheat ? Has it got a water leak ? They normally only get piston trouble with overheating, even with hard work. Another thought, is the compressor piston okay ?

Mike

 

[darylat8750ft]

Hi Mike,
No previous sign of distress. Water temperature at incident was not quite touching the begining of the red (I have an addenum to the manual that says due to calibration the normal range includes the first couple of red marks). This is where it has run under load since new. Oil was in the middle of the marks on the dipstick. One error I made that might have effected this is when I stepped on the clutch the rpm had already dropped so low that it was loaded up and running so rough that I was concerned about mechanical damage and I shut it off. After a minute or so I cranked it over to check for sounds of rod damage, and it fired right up, but with blow by. In retrospect this may have caused localized heat build up and caused my problem. I would also appreciate comment on whether or not there should be compression "rattle" under load when throughly warm. Is it possible for the fuel injector timing to be to far advanced? I understand these had higher compression before EU emission standards caused them to be lowered, If this is true, are any of the higher compression pistons available? With only 526 hours on it should I replace the liners if the cross hatch finnish still looks good? (Assuming I can knock down the step at the top of the ring travel.)
Thanks,
Daryl in WY

 

[ixer0]

Hi Daryl
I'll try to answer all your questions.

Stopping it when hot shouldn't hurt it. It's not as precise as your racing engines used to be !!
These engines don't normally have any rattle when hot.
Timing could be wrong but if it starts okay it's unlikely, unless the pump drive shaft has twisted but that would make it retarded.
I wouldn't play around with different pistons. All you could do is fit 1.2mm head gaskets.
With only 526 hours on the clock there shouldn't be any wear on the liners, so just hone them out and fit new rings. (assuming it hasn't siezed one)

Mike

 

[darylat8750ft]

Thanks Mike,
Just in for lunch. It already has the 1.2mm head gaskets, so I guess cleaning up the ports is all I can do to improve power. Above the stopping point for the top ring it was smooth enough that I couldn't feel a step with my fingernail, (after I cleaned off the carbon) and the cross hatch continued above that point. I don't have the pistons out yet. (It seems I should get everything cleaned up good before I push the pistons out to keep crud out of the bottom, I taped off the fuel stuff and stuffed rags in the push rod holes.) Unless I see something else when the pistons are out I should be able to save the liners with just a hone.
Any other input from anybody about the possible causes of compression "rattle" (predentination?) would be appreciated.
Thanks again,
Daryl in WY

 

[darylat8750ft]

Another update,
3 good cyls and one scored. Pulled the piston and liner, top 2 rings welded to piston. I guess I have to chalk this up to operator error. I should have known better that to lug it that long. New parts should get here next week. It will go back together quicker than it came apart.
Thanks all for your input. Without a forum like this it would be hard to recommend a Zetor in the USA. But with it owning one is reasonable.
The heads were pretty carboned up. I'm hoping that cleaning every thing up will reduce the compression rattle.
Daryl in WY

 

[dave_peters]

I dont think you could have done that by bad driving. these things happen with the best of tractors, but it would be a good idea to have the relevant injector checked, and make sure the index marks on the body are in line before you re install it.
Dave

 

[ixer0]

Daryl

This still sounds like an overheating problem. I would be inclined to fit a new thermostat if you can't find a leak anywhere. They don't normally run near the red over here in the UK.

Mike

 

[darylat8750ft]

Thanks Mike and Dave for the input.

When I removed the liner there was some stuff that looked like flocking or an old deteriated (sp?) cotton ball between the cyl. and the water jacket. It was on the other side of the cyl from the scoring. I cleaned it out and will flush the cooling system before use.

Do I need to seat the new rings with mineral oil or will they seat in ok using the regular 15-40 Rotella oil I always use?

Thanks
Daryl

 

[ixer0]

Hi

Just use ordinary engine oil Daryl. It's not a Chevy !!!

Mike

 

[crankshaft]

If you use a snow blower You must check your air cleaner priodicly.
My 7245 has the same problem and a lot of wather in the bottom air cleaner was the problem. The whater melt with the oil and is aspired by engine.
Langis

 

[treaney]

At 8700 feet (2636m) elevation the boiling point of water is 91 degrees C. So your temperature gauge will read 10% higher than if you were at sea level.

Did you ever do anything about putting on a turbo to give the engine more air?

 

[Renze]

Daryl, making your engine lug for long, shouldnt hurt it: We dont know any better, last month i was pulling a 11 tine chisel at 30 cm depth in 2nd gear, with the 5245. The exhaust elbow was red hot glowing in the dark, even though i have fitted a 60mm pipe off a turbo 7341.

I think this is bad luck, or an overheated piston. Check the injector of that cylinder, if it isnt spraying, but dripping the fuel on the piston, it can overheat and seize the rings.

Usually making these engines work, makes them healthy, as the hotter combustion temperatures burn out the carbon buildup in the ring grooves, reducing blowby.

 

[darylat8750ft]

Thanks for the input guys,

The tractor works good enough with the snow thrower that I have decided messing around with the turbo isn't worth the $ and effort. I also now have some concerns about reliability and don't want to cause myself needless irritation.

I checked the injectors and they all sprayed good at the correct pressure. I tried to get the 1.2mm head gaskets but Peter said I should use the 1.5mm and that he does not stock the 1.2mm anymore. The parts came quickly but I have been on a trip for work so no progress in the last week. I should get it back together this afternoon or tomorrow.

The local Zetor guy said that he had one problem that he thought was caused by bad fuel that had gasoline mixed in it. Apparently some of the local fuel suppliers haul diesel in the same trucks that they haul gas in and sometimes they don't get compleatly emptied before diesel is added. Or, could it be that they add gasoline for a "winter blend"? I'll call my supplier and ask about that. It makes sense to me that gas in the fuel would make it fire and burn quicker, and possibaly cause the detonation knock.

In any event the lower compression ratio of the thicker head gasket should reduce that tendency. (Although at this altitude I have trouble thinking cylinder pressures could be an issue.)

Daryl

 

[darylat8750ft]

Thanks for the help guys. It's back together and seems fine.
I'll run it through a few more heat cycles then retorqe the heads and recheck the valve clearances. I'll get some fresh fuel from a different supplier before I really make her snort. I will let you know if there are any other issues.
Daryl in WY