IH 674 Diesel - Using/Blowing oil

Sorry for long post. I use my IH 674 Diesel about every two weeks during the summer for 1.5-2 hours for light mowing/bush hogging. It has always used a quart or less of oil between uses. The last couple of times I noticed it using 2 or 3 quarts. This past weekend I used it for about 3.5 hours with the last couple of hours in very heavy tall grass and weeds. I noticed when working very hard that the crankcase breather tube was putting out some whitish steam/smoke with some oil dripping. I kept an eye on the oil guage and noticed pressure start to drop from 50 or so to about 25. I stopped the tractor and checked the oil. The dip stick would barely touch any oil. Didn't have any more oil so I parked her. Checked the air filter, it had a little stuff in the intake tube (probably from a rat), but not enough to stop off more than a small portion of the air. The air filer itself was pretty clean. It does not appear to be blowing oil smoke at the exhaust. Could it be a stuck ring? Broken ring? It's not running hot or using water. No water in oil or oil in water. Thinking of changing the oil and adding some Lucus oil treatment. Any other ideas to try?

Thanks

Sounds like a compression problem. Compression get by the rings.Bad rings worn or broken will cause the blow by and oil consumption.

MAY WANT TO TAKE A SAMPLE OF OIL TO A LOCAL DEALER AND CHECK FOR ANTI-FREEZE.A LITTLE OF IT CAN WIPE OUT THE MAIN AND ROD BRGS.THEN THE OIL RINGS CANT WIPE OFF THE EXCESS OIL FROM THE ROD BRGS.THIS WOULD EXPLAIN THE DROP IN OIL PRESSURE.
IF SO THE CYL O-RINGS ARE BAD LEAKING COOLANT INTO OIL PAN

Is it possible that oil is pumping to the top of the motor but not getting back to the oil pan fast enough due to clogged ports. Wouldn't the buildup of oil up top end up in the vent tube? Just an idea. I'm not real knowledgable in this area. It doesn't seem like a gradual loosening or wear of the motor since it occurred relatively rapidly. I think the drop in oil pressure was due to low oil in the motor.

if your not working it and getting it up to operating temp.that probably is your biggest problem. change the oil and hook it to an impliment and go out and work it hard for at least half a day. i have seen this before with yard tractors, they just idle around and stop and start an then their going through oil gotta get that glaze off the cyls. and get them rings to expand into the cyls.dont put any additive in when doing this.

The 674D has a D-239 German Diesel engine in it. As someone else said the German Diesels like to be worked hard.
How many hours are on the tach? These German Diesels are good for well over 15,000 Hrs if proper maintenance has be performed. A couple quick checks:
1)check for oil leaking out the bottom of the clutch inspection plate. Could be loose rear main seal.
2)There was a change to the older D-239 with the crankcase vent tube as oil would leak out the crankcase tube if the tractor was on a steep incline or right side on downward slope.

JimB

Attached is a picture of the tractor vent tube. This was taken right after I repainted a few years ago. Doesn't look quite that good now! The tractor is about 50 miles from me this week, but I'll check the inspection plate this weekend. I'll also try working it hard. I do some mowing at steep inclines, but the steep stuff was with the tube up the hill this past Saturday. Thanks

I forgot to mention in the previous post that I don't know how many hours are on the tractor. It was rebuilt some years before I purchased. It really hasn't been worked very hard in the last 10 years or so. Some mowing in the summer and breaking up a garden in the spring, deer plots in the fall, etc. It has always cranked relatively easy, not used much oil and maintained good oil pressure.

Go to caseih.com, parts, search for parts and enter D-239, go to figure D-08 and look at the crankcase breather options.

JimB