12.7 Detroit leaking oil from blow by tube

Mine has horrible blowby. So much that I extended the hose to exit by rear axle as the exhaust was filling the cab. It smokes nonstop when idiling Using 2 gallons of oil a week and 3-4 gallons of coolant. Still running loads and making money lol. This is why I’m replacing engine soon. Real soon.

 

Another idea I had, was to run it into hoses, or pvc even, splitting it, into 2, the splitting those into 2. Each time going to a larger hose. Diluting it from 1 big smoker to 4. By increasing the size, each time, it would cut down on any chance of getting plugged like mine did in the snow storm. The tube stays hot, when it’s short, doesn’t have a chance to freeze. All goofy ideas. The single hose ran back worked, till it got froze up. Had it ran on a constant downward slope, so oil wouldn’t pool. Catch can will work. Just ideas I’ve had. The excessive blow by is aggravating. Seems to be less, if oils changed more often. I went back to 15k, original Detroit spec. 20ks plenty for the bearings. Maybe not for the rings? Idling makes it worse, like the cylinders get glazed. Supposedly will happen from idling, mainly from being too cool, and not having and side force put on the sleeves. I really don’t know. Just things I’ve read and heard.

 

That’s how mine was. The smoke looked like were on fire, after running it back. Ran it at least 5-6 yrs and 500-600k miles that way. It got real bad about 750-800k.

 

It’s amazing and another testament to the awesomeness of the S60. In the beginning I thought everyday would be the day the motor finally gave up, especially when the cold weather moved in.

 

there is no reason not to drive it as far as you need to get the service you want. if the engine is tired it is tired how many miles on it

 

i owned a fishing boat with a ww2 grey marine every detriot will keep running maybe not well bt running

 

Had to look that up. Very cool.

 

The blow by is the rings, maybe worn valve guides. Sometimes a 60’s car would pour smoke, burning oil when accelerating. Getting dubbed a clunker, or oil burner. Car needed a ring job at only 40-60k miles. Problem was it cost $300 in the 70’s. More than the car itself. The only logical thing to do was keep oil in it, if not, it would spin a bearing. Otherwise it would run another 60k. That’s how the 12.7s are. The bearings hardly wear. For some reason the rings and cylinders wear out. The rest is still bullet proof, and dependable. Just have to keep oil in it. Lol. The first ones had factory suggested rod and main replacement interval of 500k. After inspections, they raised it to 750k. Soon thereafter 1 mil. Engines with 1 mil. showed no bearing wear. Detroit was surprised. It’s a heck of a story. At the time, Cats B model were suggested every 250k. Till about 1992, 5 years after the 12.7. Then the C model was 500k. Not till the E model came out in 95 or 96? Could they go 1 mil. like a Detroit. A lot of Detroit’s only made 750-850k, still they were dubbed the million miles engine. Do you know when it was manufactured? The date on valve cover? Is it a GK, PK or MK? Engine model.

 

1996 GK

 

I dont have much blowby(smoke) but just very little oil only when driving, it doesn't drip the oil when just sitting and idling(Warming up in the morning or shutting down at night) I dont idle as I have an APU. Its enough oil that after a few thousand miles ill have oil on my fenders over my drive tires.....

I was advised to wait until I get a valve adjustment to change/clean the mesh crankcase filter. But I think a question I always have had in the back of my mind has been answered.......

When I go to check my oil, Im having to wipe oil off the dipstick off the top, kinda like its blowing oil up the stick(not out of the dipstick tube though).

So.....I need to change my crankcase breather??? Engine has 500k miles, tuned up to 600hp, runs VERY strong, I do heavy haul so I dont even keep track of fuel mileage, my recent IFTA was 5.1 mpg I believe. Uses about a quart of oil every 12k miles.