Mx5100 spitting the dipstick out?!?

[The Fred]

I believe there is a crankcase breather valve on the valve cover. There is a hose from this valve to the intake manifold. I am assuming your engine is fairly similar to my L5740. The workshop manual doesn't illustrate the valve very well - there is a top view showing 4 attaching screws holding a cover that might access the valve. On my tractor I can barely see the hose because of 2 tanks covering it. Back in the 60's when they first started putting PVC valves on cars my dad bought a car where the corresponding valve tended to freeze in cold weather and blew out the valve cover gasket a couple times before they came out with a fix. This sounds like what is happening to yours. And yes, PVC is new to many off highway diesels. Tier 3 engines I worked with still had an open breather tube - just an open hose that directed the fumes down and out. Your 2012 tractor under 75 HP is Tier 4 interim and I believe PVC became required. The only older diesel I still have is a 2005 mini-excavator with a straight out hose and the crankcase fumes from that little engine are quite impressive, and smelly. It sounds like Kubota has a problem with their valve that cropped up due to this odd winter.

Just to the right of the beer bottle, 4 screws, remove carefully because there is a diaphragm and small spring underneath. Most likely it froze there. Good luck! Fred

 

[Wayne64SS]

I don't think it's a pollution thing at all. I think the breather tube is to get the cranckcase vapors away from the intake so the filters stay clean.

Also, if too much vapor were fed back into the intake, under the right conditions the engine could run away.

It is in fact STRICTLY for emissions. The recirculate back to the intake.

On a lot of the old 2 stroke detroits the vent was run to the air intake. I don't think I've ever seen that on a 4 stroke diesel. A lot of them run a hose or pipe from the actual breather cap to some sort of remotely mounted canister or filter where oil mist is trapped but the gasses can still vent.

Maybe the newer silver series, all the old ones just had a dump tube. As a matter of fact the only ones I have that recirc like a normal emissions engine is the newer 6v53t military power packs.

 

[nspec]

"I don't always drink Dos Equis, but when I do, I put turbos on little tractors....stay thirsty my friends...."

 

[nspec]

(that was meant for Fred's picture)

 

[The Fred]

(that was meant for Fred's picture)

It is in fact STRICTLY for emissions. The recirculate back to the intake.

Yup it is all about emissions Wayne. Be ready for all the emissions related BS of the 60 series tractors coming to a farm near you soon!

I have a photo of the actual diaphragm somewhere been looking for it. It's made of the same orange silicone crap that all the car OEMs use. After time they split/tear and cause a check engine light. Not on Kubotas YET LOL!

Fred

 

[tjkubota93]

Run a loop of1/4" or 3/8" hose with hot engine coolant around the valve/hose that freezes. Alot of cars and trucks have coolant through the pcv valves now.

 

[rsallen]

Replace the thermostat........or put a piece of cardboard in front of the rad.

 

[MHarryE]

Primary products of diesel combustion are carbon dioxide and water. The water vapor that gets past the rings into the crankcase has to go someplace and that path is out of the breather. It hits your cold PCV valve and freezes blocking the passage. Blowby must go somewhere and the dipstick is the path of least resistance. There may be no problem running without the dipstick until things warm up but that narrow tube may be too small to handle the blowby and like someone mentioned, the next weakest point may be a crankshaft seal. Something like this happening on a modern engine after 50 years of history with positive crankcase ventilation is due to PPD - P*** Poor Design if like you say your dealer is reporting a shop being loaded up with machines having the problem. You have me worried because I have 3 Tier 4 interim Kubotas; however, the one that now has about 250 winter hours over the past 2 years has not had a problem so maybe the heated garage is the answer.

 

[The Fred]

Run a loop of1/4" or 3/8" hose with hot engine coolant around the valve/hose that freezes. Alot of cars and trucks have coolant through the pcv valves now.

That's a really great idea. Maybe insulate over the top of the valve cover just for cold weather. That pink Owens-Corning stuff will take the heat of exhaust headers with no problem, the mice love it too.

Fred

 

[tjkubota93]

Thanks. Maybe use copper for the heated area and rubber to get it there?