NX crankcase pressure

[Kioti Dave]

Are you using a block heater?

Yes, do use a block heater. This did happen last winter as well. That may be why my rear main seal began to leak. Will have to be careful not to run when this happens again. I try not to use tractor when it is very cold, but when the driveway snows in.... I am concerned this may happen again. Would there be any harm in tapping into fill cap to add another bypass to avoid any seal damage?? If it is a design flaw, what could a person do to avoid this?? I guess a heated shop would solve that.

 

[justman777]

Took a look at the service manual. These tractors do have a PCV valve. Sits on top of the valve cover on the end opposite the fill cap. It has a circular metal cap over it that is attached by what appears to be three screws. The blow-by hose looks like it's 3 or 4 inches in length and is connected to the PCV valve and goes into what appears to be the intake manifold. I'd open that up and see what you can see.

 

[Kioti Dave]

Took a look at the service manual. These tractors do have a PCV valve. Sits on top of the valve cover on the end opposite the fill cap. It has a circular metal cap over it that is attached by what appears to be three screws. The blow-by hose looks like it's 3 or 4 inches in length and is connected to the PCV valve and goes into what appears to be the intake manifold. I'd open that up and see what you can see.

Yes, it is finally going to 'warm' up to 0 celcius tomorrow, 32 in your world. Will have a good look. I will have to remember to ask about the heat in the summer. Thanks for the help.

 

[justman777]

Yes, it is finally going to 'warm' up to 0 celcius tomorrow, 32 in your world. Will have a good look. I will have to remember to ask about the heat in the summer. Thanks for the help.

No problem. Helps me learn things about my own tractor!

You may try a hair dryer or heat gun to warm up the PCV valve or bypass hose before you use your tractor. Seems if your issue goes away after the engine runs for a bit and warms everything up, something freezing up would be a likely cause of your issues.

 

[Kioti Dave]

Took a look at the service manual. These tractors do have a PCV valve. Sits on top of the valve cover on the end opposite the fill cap. It has a circular metal cap over it that is attached by what appears to be three screws. The blow-by hose looks like it's 3 or 4 inches in length and is connected to the PCV valve and goes into what appears to be the intake manifold. I'd open that up and see what you can see.

On my 2016 model, there appears to be a 3/4" rubber hose about 10" in length that goes from side of valve cover to intake tube. There is no PCV valve visible. Fired up tractor and no pressure build up. Can't see how the 3/4 " rubber hose could get completely plugged. Will take apart intake to see if there is a valve inside?

 

[xcgreene]

That snip I took in post #8 of this thread is a screen grab from the kioti Workshop manual. and should be exactly what the DKse and most likely NX series tractors have.

I'm shooting from the hip here, but it is possible that the oil heater, if its not big enough or hot enough for extreme colds, may be causing the problem. If only the bottom of the engine is hot, moisture will rise up to the valve cover area, and if there is not enough heat to keep pushing the moisture out of the engine entirely, and it is super cold, The moisture will condensate and freeze back up right at the top, where the pcv system is. Especially if the engine is only run in short increments in the cold, where it does not have time to steam off all moisture gathered.

Worth a check during the next hard freeze, to see if your valve cover is still well below 32deg with the heater still on.


This is one of the reasons I prefer the lower radiator hose jacket water heaters, as opposed to the sump pad type. The hot water really gets around the whole engine with the former, if its big enough.

 

[justman777]

On my 2016 model, there appears to be a 3/4" rubber hose about 10" in length that goes from side of valve cover to intake tube. There is no PCV valve visible. Fired up tractor and no pressure build up. Can't see how the 3/4 " rubber hose could get completely plugged. Will take apart intake to see if there is a valve inside?

If you take a look at XCGreen's earlier post with the picture, it shows the valve cover assembly. To the rear of the valve cover assembly is a round cap held on by three or four screws. The picture only shows three, but I suspect there's a fourth screw on the backside. That round cap covers the PCV valve. The tube you found (blow-by tube) comes from the PCV valve and goes to the intake manifold. If you pop that cap off, the PCV valve should be underneath it.

Also, XCGreen is correct in that the DK and NX series share common engine configurations. The graphic he posted is the exact same in the NX workshop manual. The graphic I referred to in order to find the PCV valve is on page 3-80 of the NX workshop manual. The one he posted is found on page 3-41 of the NX workshop manual.

 

[Kioti Dave]

If you take a look at XCGreen's earlier post with the picture, it shows the valve cover assembly. To the rear of the valve cover assembly is a round cap held on by three or four screws. The picture only shows three, but I suspect there's a fourth screw on the backside. That round cap covers the PCV valve. The tube you found (blow-by tube) comes from the PCV valve and goes to the intake manifold. If you pop that cap off, the PCV valve should be underneath it.

Also, XCGreen is correct in that the DK and NX series share common engine configurations. The graphic he posted is the exact same in the NX workshop manual. The graphic I referred to in order to find the PCV valve is on page 3-80 of the NX workshop manual. The one he posted is found on page 3-41 of the NX workshop manual.

I think you guys are correct. My shop manual from 2016 doesn't have the same photos, so thanks for the diagram. It does take forever for the engine to warm up. Think a block heater and an oil pan heater would help? The engine was at operating temp when this happened though. After I let it sit for 15 minutes it was fine (shut the engine off) Can the PCV get 'stuck'?

 

[xcgreene]

I think you guys are correct. My shop manual from 2016 doesn't have the same photos, so thanks for the diagram. It does take forever for the engine to warm up. Think a block heater and an oil pan heater would help? The engine was at operating temp when this happened though. After I let it sit for 15 minutes it was fine (shut the engine off) Can the PCV get 'stuck'?

Yes they can. Have a look at this screenshot here, a different view than before. Just take the 4 screws out and have a look at the baffle plate, #5. It could be gummed up stuck against the seal.

A quick thing to rule out while troubleshooting, and with some luck, it could solve your problem.

 

[Kioti Dave]

Yes they can. Have a look at this screenshot here, a different view than before. Just take the 4 screws out and have a look at the baffle plate, #5. It could be gummed up stuck against the seal.

A quick thing to rule out while troubleshooting, and with some luck, it could solve your problem.

View attachment 637831

Thanks for the picture. Will take apart when it is warmer. Sure miss the old tractor. Looks like I may have to take off hood just to have room to get this apart. :confused2: