Oil & Fuel blow by

[sebes]

I own a 1989 B9200hst with a Montana FEL. my hour meter does not work, meter says 662 but I'm guessing is has 1000 hrs on it. I am starting to get some blow by out of the crank case vent with very little oil. I have no idea how much is normal or if I'm living on borrowed time. I have to use the glow plugs when starting cold (is that a sign of low compression?) a rebuilt engine is north of $3200 ouch! Any input would be greatly appreciated!

thanks in advance

 

[repete]

I own a 1989 B9200hst with a Montana FEL. my hour meter does not work, meter says 662 but I'm guessing is has 1000 hrs on it. I am starting to get some blow by out of the crank case vent with very little oil. I have no idea how much is normal or if I'm living on borrowed time. I have to use the glow plugs when starting cold (is that a sign of low compression?) a rebuilt engine is north of $3200 ouch! Any input would be greatly appreciated!

thanks in advance

Before I did anything engine wise I would be sure I had a good strong battery and good connections to get the fastest crank speed possible.

 

[moship]

Blow by happens from day one as ring seal is never 100%. The real question is how much blow by are you getting. Oil will always be in the mist. Again it’s a matter of the volume. I’ve seen some engines have a spec for blow by where a flow meter is connect to the vent so the flow rate could be quantified. Having said that, The only proper way to assess ring seal is by compression and leak down testing.

Is the oil contaminated? If ok I’d continue to run assuming power has not diminished, no odd engine sounds, etc.

If you desire a new tractor use this as an excuse to buy a new one.

 

[TractorGuy]

First thing to do for any signs of blowby is to check the vent system. If it has a PCV valve make sure it isn't clogged. Same for the hose and nipple. Some PCV nipples will have a small hole or orifice in them. Stick a wire down in that to make sure it isn't stopped up and the pressure can escape back into the intake.

Before I rebuilt and engine for blowby I would add a vent or reroute the vent to a catch can. As long as you get it to start and run acceptably to get your work done that would keep it from blowing seals out. Leave the system with too much pressure inside and it will push out the engine seals.

 

[Dave M7040]

Your tractor is dying for a few days of very hard work.

If you are using a synthetic oil, stop. It is too good a lubricant and many diesels cannot keep their piston rings sealed when you use the synthetic.

Diesels who spend their working time at med to high revs and no load develop a condition called "diesel slobber." You are in the early stages of this condition.

The type of load your tractor needs is the pulling a heavy trailer up a long hill with the exhaust starting to blow a little black smoke. These loads build up high cylinder pressures and keep the rings seated against the cylinder walls. Pulling a plow through the field.

Dave M7040

 

[Spiros]

Had an old Massey at the airport used to mow the rough grasses with a 10 foot bush hog. It developed blow by so bad that it would build up enough pressure to blow the dipstick out of the crankcase. We still mowed with it for over five years. Compression rings gone bad.

 

[aczlan]

I have to use the glow plugs when starting cold (is that a sign of low compression?)

We have a B7500 and even when it's 90° out, you have to use the glow plugs to get it to start. I would not be concerned about needing to use the glow plugs to get it to start based on the experience we have had with our B7500.

Aaron Z

 

[DK35vince]

We have a B7500 and even when it's 90ｰ out, you have to use the glow plugs to get it to start. I would not be concerned about needing to use the glow plugs to get it to start based on the experience we have had with our B7500.

Aaron Z

+1
Some blow by is normal.
Most of the Kubota, Kohler and DaeDong diesel engines I have run all required the glow plugs to start since new.
Is it using excessive oil ?
If not it doesn't sound like you have an issue.