Mx5100 spitting the dipstick out?!?

[KennyG]

The crankcase has to be vented to relieve the pressure as the engine warms up and the air inside expands. It also has to vent the fumes if there is blow by from the pistons. I think most modern engines are vented to the intake, but that really doesn't make a difference. If the vent path is such that moisture will condense and freeze as it passes through the vent system, it will block the vent and the pressure increase will blow out something, most likely the dipstick.

I think it's a design problem. I've only had this happen to one vehicle, an old Fiat 124 and everything on that car was a design error.

 

[KennyG]

Oh, by the way, I cleaned every bit of the Fiat vent system and couldn't fix it. I just drove it without a dipstick in really cold weather. One mechanic told me most people didn't have this problem with their Fiats because they couldn't start them in cold weather. :laughing:

 

[Purdyfarm]

So here's my question...where on earth is this 'freezing'? And do they mean actually freezing like with ice, or are they saying it gets plugged? I'm thinking the hose that runs down to the underside of the tractor from the breather cap is freezing from deep snow or more likely condensate is slowly freezing to the point where the tube gets blocked. If that is the case, I would simply shorten the hose so the end is up inside next to the warm engine and not underneath the tractor. You could even make the aforementioned cannister to keep things clean. I can't imagine it's the actual breather cap freezing as it is on the valve cover on top of a warm engine. This should be a pretty simple fix.[/QUOTE]

The breather cap is located on the top of the valve cover, the hose that comes off of it is about 6 inches long and ties in to the intake. according to the dealer the moisture is a common thing in the breather, which makes sense because all motors produce some moisture. I guess the issue is the new design to the breather itself. It appears to come off with 4 screws but on my model tractor I have to remove the fuel take to get to the screw to take it off.

 

[MHarryE]

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.

 

[Purdyfarm]

FatTire, the temp gauge barley comes up off the bottom.

 

[Purdyfarm]

KennyG and MHarryE I believe you are both correct, an engineering issue! Oh wonderful!!

 

[AStanton]

If it is some type of valve hanging up, can't you spray it with some lube like Tri-Flo? Locksmiths put this in locks to prevent them from freezing.

 

[nspec]

Can the pcv valve be removed/elminated and vent to atmosphere as in pre emission days? Obviously dealer won't do it but perhaps it could be done by the owner? Never seen a diesel with a pcv valve. I'm around larger motors and even the tier 4 engines have a cranckcase vent filter - the vent goes straight to a filter cannister which captures the oil mist and allows gases to escape. Just a tube from the valve cover to the filter - no valve.

 

[Recoveryhill]

Oh, by the way, I cleaned every bit of the Fiat vent system and couldn't fix it. I just drove it without a dipstick in really cold weather. One mechanic told me most people didn't have this problem with their Fiats because they couldn't start them in cold weather. :laughing:

I got a chuckle out of that one! "Fix It Again Tony"

 

[Baby Grand]

The crankcase has to be vented to relieve the pressure as the engine warms up and the air inside expands. It also has to vent the fumes if there is blow by from the pistons. I think most modern engines are vented to the intake, but that really doesn't make a difference. If the vent path is such that moisture will condense and freeze as it passes through the vent system, it will block the vent and the pressure increase will blow out something, most likely the dipstick.

I think it's a design problem. I've only had this happen to one vehicle, an old Fiat 124 and everything on that car was a design error.

I had a 1971 SAAB 99 that started pumping engine oil thru the rear seal one very frosty morning on my way to work. Condensation in the PCV valve froze it in the closed position after I shut it down the night before, allowing the crankcase to pressurize on warming up the next day. Replaced the PCV valve and never had the problem again.