NX crankcase pressure

Kioti Dave · Jan 17, 2020

It has been pretty cold here lately in Western Canada. Today, engine blew out crankcase dipstick due to high pressure. I am assuming that a vent hose is frozen. Anyone else see this happen to them?

justman777 · Jan 17, 2020

All of these odd issues with people in the cold North make me glad to live in Texas! It was 72 degrees Fahrenheit here today. Had to turn on the AC because the house was getting warmish and muggy. Can't open the doors due to it being Mountain Cedar season. If you live in South Texas, you know what that means...

But to answer your original question, no, I haven't had that happen. Shouldn't the PCV or other valve take care of excess pressure? Do these things even have one? Hmm...

xcgreene · Jan 18, 2020

Most newer diesels do have a Positive Crankcase Ventilation valve (PCV) Some of them can freeze up if its a certain type and in the right situations. If you only ran the engine in short stints, where there was enough moisture still steaming off in that PCV system, then shut down during a very cold snap, I have seen this happen before. blew the dip stick right out of the tube. Not good for the engine seals, don't run it this way if you can avoid it. An air dryer of sorts over the PCV valve will free it up.

On an older tractor, I had some mud wasps make good use of the crank case vent tube, plugged it up real good. Found out in a similar fashion.

On a 22r Toyota gasoline engine I've seen the front main seal blow out due to a stuck PCV valve while driving. Oil everywhere in the engine bay. Looked like this one had gummed up, as opposed to freezing.

Kioti Paul · Jan 18, 2020

My older (DK45) has "positive" crankcase venting, but it simply consists of a (very short) hose that runs from the valve cover to the intake manifold. Because there is no throttle (air) valve, there is no need to have a PCV valve to restrict manifold vacuum loss at low power settings.

I cannot visualize how a PCV valve could work in a diesel, or why there would be any need for one. I do agree if you have (any measurable) crankcase pressure, it can be very detrimental to your crankshaft seals. My crankcase vent hose runs from the rear of the valve cover, to the rear of the intake manifold, maybe 1 foot long.

Kioti Dave · Jan 18, 2020

justman777 said:
All of these odd issues with people in the cold North make me glad to live in Texas! It was 72 degrees Fahrenheit here today. Had to turn on the AC because the house was getting warmish and muggy. Can't open the doors due to it being Mountain Cedar season. If you live in South Texas, you know what that means...

But to answer your original question, no, I haven't had that happen. Shouldn't the PCV or other valve take care of excess pressure? Do these things even have one? Hmm...

Had to rub it in hey!

it's was minus 42 here the other day. ( same in farenheit or celcius) after I let the tractor sit for a few minutes it was fine. Did it once last winter as well. The hose from valve cover seemed fine. Something is frozen.

K5lwq · Jan 18, 2020

Kioti Dave said:
Had to rub it in hey! &#55358;&#56694;&#55358;&#56694;&#55358;&#56694; it's was minus 42 here the other day. ( same in farenheit or celcius) after I let the tractor sit for a few minutes it was fine. Did it once last winter as well. The hose from valve cover seemed fine. Something is frozen.

Pretty sure everything is frozen at those temps! That is crazy cold!!

Kioti Paul · Jan 18, 2020

Kioti Dave said:
Had to rub it in hey! &#55358;&#56694;&#55358;&#56694;&#55358;&#56694; it's was minus 42 here the other day. ( same in farenheit or celcius) after I let the tractor sit for a few minutes it was fine. Did it once last winter as well. The hose from valve cover seemed fine. Something is frozen.

We're laughing now....You will get your laughs in July, when it is 105 here!

xcgreene · Jan 18, 2020

Kioti Paul said:
My older (DK45) has "positive" crankcase venting, but it simply consists of a (very short) hose that runs from the valve cover to the intake manifold. Because there is no throttle (air) valve, there is no need to have a PCV valve to restrict manifold vacuum loss at low power settings.

I cannot visualize how a PCV valve could work in a diesel, or why there would be any need for one. I do agree if you have (any measurable) crankcase pressure, it can be very detrimental to your crankshaft seals. My crankcase vent hose runs from the rear of the valve cover, to the rear of the intake manifold, maybe 1 foot long.

Here's a snip from the Kioti manual for the DKse tractors. Really isn't much going on there, but #11, the oil baffle plate, would be easy to have a look at.

If OP can rule that out, its one more thing off the troubleshoot check list.

Kioti Dave · Jan 18, 2020

One other thing I forgot to mention. There was engine oil coming out the muffler. Probably due to increased pressure in engine? After the crankcase pressure went away and the excess oil in the muffler burnt off it all seemed fine. No mention of PCV in shop manual.