D722 Engine Question - Puffing Smoke and Oil out of the breather hose

[rmcard]

This question is related to the problem I had posted last week about blowing my main oil seal on my G1900 because of a Mud Dauber building a nest at the end of the hose.

Since re-inserting the seal and putting a couple of hours on the tractor I've noticed that I do get significant puffing of smoke out of the hose (which runs to the rear of the tractor) as well as oil dribbling out and puddling on the ground if it sits for long enough.

Is this a problem? I've put my thumb over the hose and there isn't that much pressure that I can't easily keep my thumb there, I can't hardly detect any pressure at all.

But it did build up enough to blow a seal.

As for the oil dripping out, before I get too excited I've ordered a new foam breather element to install into the top of the valve cover because I suspect the current breather element is probably compromised.

Is the smoke and pressure normal for this engine? Or am I looking at maybe broken rings or blown head gasket? The tractor doesn't overheat and runs strong and smooth. No other problems have been detected.

Let me know if any of you have had experience with this or can assure me that my tractor is running normally.

 

[Repair]

how many hours are on the tractor?

You could run a compression test to see how worn out the rings are and then you would know.

Some blow-by is normal but is the amount that your engine is putting out excessive, that is the million dollar question and it sounds like it is excessive.

 

[rmcard]

The engine has almost 1100 hours on it, which doesn't seem like a lot.

I'll try to do a compression test on it this weekend.

 

[Repair]

The engine has almost 1100 hours on it, which doesn't seem like a lot.

I'll try to do a compression test on it this weekend.

After you do the test put some oil in the cylinder and retest, if the readings are effected then it's the rings if they don't change it's the valves.

 

[Delmar]

Compression test will be very informative. Just FYI, when I was doing a compression test on a D722 it was a challenge to avoid buying a proprietary Kubota tester. I had a thread on here that you might want to find. None of the tester kits I could find had an adapter that would work. I ended up using (successfully) a paintball gun fitting. I think I've still got it around somewhere and would be happy to send it to you to use. Good luck!

 

[ThisIsNotaStep]

Selfish question .. where is the breather hose on a BX23 .. I have allot of wasps, and don't want to learn the hard way .. come to think of it seems like every critter down at the lake is out to get me! Thanks

 

[lugbolt]

I would not use oil in cylinders on these little diesels. A tiny bit too much oil and you'll end up with a bent rod or two.

Smoke out of the vent hose is subjective. How much? There is going to be "some" blowby with 1100 hours but how much is too much??

Did I read that correctly? Breather hose routed to the back of the tractor? It should just run down the side of the block and dump near the oil pan. A long hose run to the rear, may I ask why it's done that way?

 

[rmcard]

Hi Jk, I'll have to look at my tester to see what adaptors it has, I know I can also purchase more from the manufacturer's website. But if I strike out I may take you up on borrowing your adaptor.

Lugbolt, looking at my valve cover vent hose more closely it appears that its a clear fiber reinforced hose that is probably aftermarket and most likely installed by the previous owner who then ran it to the back of the machine along the frame. I took a video of me starting and running the tractor this evening and will load it up to photobucket once I can get back into my Verizon cloud service. It appears to be on the fritz right now.

 

[D2Cat]

You're in Michigan. If you have a low spot in that hose running to the rear of your tractor you could get condensation in there it freeze. Might cause you some additional problems.

 

[lugbolt]

Running a long hose out to the rear is not a great idea. I am thinking that the PO did it because there was crankcase fumes/oil vapors being blown down the side of the engine, so they re-routed it to the back. If that's the case, it's likely a good time to rebuild the little engine.

Running that long of a hose to the rear is going to cause some restriction of air flow. That can cause the engine to build more pressure in the crankcase than it was designed-especially if the engine is worn. And that can cause other seals, gaskets, etc to begin to leak. All the new engines have the crankcase vent routed into the intake manifold, which I don't personally care for, but the oil sure stays cleaner, the exterior of the engine area stays a LOT cleaner, and there is less chance of crankcase pressure (if excessive) to cause other leaks.

 

[rmcard]

Well I did make a crappy video,
https://youtu.be/FL6g9PXOTHs
a little long but you can see at the beginning it starts with white smoke but clears up after a couple moments and then near the end I finally got a good angle you can see the exhaust coming out of the tube. A lot of what's in the middle is just bad camera work so I suggest clicking to near the end after the first minute or so.

Also, I checked and I can get an adaptor for my compression tester for around $25. What's painful is that they still want to charge me almost $10 for shipping for something that can be dropped into an envelope. And the company is in my same state! only about 150 miles from me!

 

[rmcard]

I was a little off on where I got a good shot of the Valve cover vent tube, it's actually around the 4:20 mark on the video.

 

[D2Cat]

You can get an inexpensive DIESEL compression tester at Harbor Freight for about $30. It has an assortment of fittings. Might check them out to see if they have the correct one for your engine.

 

[rmcard]

I was able to order a competitor's brand adapter that should fit my compression tester off Newegg.com for about $19 including shipping. I'll see how quick it gets here.

https://www.newegg.com/Product/Product.aspx?Item=9SIA1B10NY7106

From the pictures on the HarborFreight website it looks like they use the same quick disconnect so the adapter should work on that setup as well.

If I really have bad compression I imagine I stand a chance of the engine running away on me and going out like a hand grenade.