Smoke coming out of tube from top of engine

pjs9370 · Dec 18, 2016

Hey I'm new to owning my deisel 755 sub compact Deere and was wondering if anyone knows if this is normal for some smoke to blow out of the top of the crank case. Looks like a type of breather tube? Would appreciate any input for a Green horn owner!

Egon · Dec 18, 2016

Depending on how much it's normal.

davesl708 · Dec 18, 2016

At first startup yes a little puff of black smoke is ok. If constant black smoke then too much unburned fuel. Possibly dirty injectors or engine needs work.
If white smoke then water in fuel or bad head gasket or other engine problem.

buickanddeere · Dec 18, 2016

Normal for some vapour from the crank case. Use a block heater instead of ether .
Is it used hard and brought up to full operating temperature ? When was the engine oil last changed ?

motownbrowne · Dec 18, 2016

pjs9370 said:
Hey I'm new to owning my deisel 755 sub compact Deere and was wondering if anyone knows if this is normal for some smoke to blow out of the top of the crank case. Looks like a type of breather tube? Would appreciate any input for a Green horn owner!

It is a vent. At least it sounds like one, and outs very likely that that engine has one.

What you're referring to is called blow-by. As the piston compresses the fuel and air, some of the gasses blow by the piston rings and into the crankcase. It's a normal condition, but wear can lead to excessive blow by, which isn't great. It won't hurt anything unless it gets pretty bad, though.

You should Google "blow-by" and learn how to determine if yours is normal. Also, that vent is how any condensation in your oil is evacuated. When the oil gets hot enough, the water evaporates and gets pushed out the vent. Tractors have relatively large oil pans, and take some time to heat up. It's good practice to use your engine hard for more than an hour every few times you use it. Otherwise, you can end up with a buildup of moisture in your oil.

pjs9370 · Dec 18, 2016

Thanks for the Info.. I'll look into this further to determine if it's normal blow-by. I just changed the engine oil. Over all I Love the machine, working vey well! I just don't want to damage my New Baby!