Detroit 12.7l burning oil and excessive blowby

We have one truck, we pulled out of the fence row, somebody ran the blow by tube(hose) all the way back to just before the tandems. lol

 

Time for a overhaul.

 

Gear oil when added to your motor will make foam in oil pan and burn up the motor

 

I'm not sure if you understand this but:

Bearings should be done at 1 million miles.. You've gone 1 1/2 times farther. Really bad idea.

If you never had the bull gear done you're on borrowed time. That is usually done before 800,000 miles. To keep running that truck is a really, really bad idea.

If for some reason I had a truck like that and the bullgear was never done with that many miles on it I wouldn't even start the truck again until it was done. At any moment that engine is going to self destruct.

You got twice the amount of time out of it than you should have.

I don't understand what you're trying to do unless this is the truck version of the Seinfeld episode where Kramer took the car for the test drive and wanted to see how far it could go before he ran out of gas.

Except in your case you're going to destroy one of the most sought after engines that exists.

Truck prices are at an all time high and even if you sold the truck you would do better than destroying it.

If you destroy it, it's worth scrap value.

Makes no sense to me. It's your truck, do as you wish.

 

If you think you can inframe it yourself, go for it. Do your research first. The counterbores will need to be checked and probably cut. That’s around $300 per cylinder. The bull gear is a bit tricky, and a lot of labor. You can run it till it blows a head gasket. Might make it home, adding coolant. Might want to check the bull gear, by taking the inspection cover, or accessory drive off. If it fails, you’ll be stranded for sure. Along with needing new front gears. Bent valves maybe. It can easily cost you double compared to replacing it before it goes. The extra money spent, will almost pay for the inframe kit, and head. A gallon of Lucas might benefit the bull gear bearing, buying time and help a bit with blow by and leaks. Too much will cause sludge. Also make it hard to crank in cold weather. I ran mine to 1.3 on an overhaul. The valve guides were so worn, the valves had actually hit the piston on one cylinder. The bull gear had over 2 mil on it, and still looked good. Too much Lucas over the previous 2 yrs. caused a lot of sludge. It never had sludge before. Pick your poison. It’s definitely worth rebuilding. Parts are some of the cheapest for any engine. I paid $7000 Labor. Including 6 counterbores and Bull gear. Parts were about $7000. Along with another $7000 in extras like radiator, cac, turbo, anything that had to come off anyways. There’s different kits, for different models. Depending on your block, you can upgrade the engine if needed. What model is it? PK? Or? Serial # info is important, date of Manufacture. That will tell if the block has oil sqirters, or at least is drilled and capped, and can be added. If so, the block is very desirable. You don’t want to risk ruining it.

 

Get it done professionally at a reputable shop. They have the right tools for the job, plus experience. Don’t use the cheap aftermarket parts unless you like throwing your money away. Get genuine parts for it. There are some threads on here regarding better turbos for the Detroit as well. Good luck and I wish you many trouble free miles to come.