12.7 detroit smoking and rattling

How is ur coolant level? White smoke can be reason of coolant leak,

 

Not necessarily a fuel issue. Could be valve train. You'll have that with no compression. Isolate by pulling the exhaust and starting.

Often you can do the manual cylinder cutout to isolate it. It may not change how it's running, but when you lose the smoke you at least know which cylinder.

 

Might have blown an injector. No coolant loss is main thing. Could have blown head gasket, or a cracked head. May be caused from dropped cylinder. I doubt it. Look at the exhaust manifold gasket around each cylinder. Sometimes a blown injector will make the gasket wet with fuel. You could take the exhaust pipe off at the turbo. Look for raw fuel. It will look like black thin oil, but it’s fuel. The problems only 1 injector. But which one. A heat gun while running might show the dead cylinder. Injector harnesses are known for problems. I’d try to avoid guessing and changing all injectors and harness, without at least a better idea/diagnosis. You can check oil, letting it drip onto a paper towel. Look for quick separation of fuel from oil on the outer edge of the oil drops. Any fuel will run quickly outwards of the drip spot. No fuel, oil drip/spot will stay consistent. A good shop should be able to tell if an injectors not firing. A bad Shop will tear it apart, then further, till you end up with a rebuilt engine. You say you smell fuel? Like excessive unburned fuel? Likely an injector. If it’s stinky raunchy smelling, almost like sulpher, might have a leaking fuel line going to the back of the head. Usually easily spotted, leaking a lot. Not always, sometimes leaking a little, down onto the hot block, and it stinks. Check them for leaking, they’re known for it. If ones leaking, replace it with a long enough hose. The original hose/metal line is a PITA and too expensive anyway.

 

One sure way is to take exhaust mainifold off to find the bad cylinder. If it’s a bad injector you can run it home. I have anyway. I ran out another 2k miles, chugging along, right before getting mine rebuilt. The rattling might be the missing sound, going through the exhaust, if it’s a blown injector. When mine blew, it almost sounded like a turbo blew, since it split the weak rusty y pipe wide open. Started running like crap, and exhaust was loud. Might want to rule out a bad turbo, before trying to run it home. I had nothing to lose at the time. Running it home is your call. I’d hate to suggest something that blows your engine. Good Luck.

 

I’d like to know what they find, since I run a 12.7 also.