I think I might have some problems in the head after the turbo blew up. If I have a dropped valve, would the motor still idle very smooth, and start with no problems? I have the turbo, all intake piping, grid heater, intercooler removed off the truck because I am replacing it all, but at idle the truck is smooth, except for this loud banging noise, I cant tell if its a normal diesel sound or there is an issue.

 

In my non-expert guess, a loud banging noise would not be normal, but I would expect one cylinder would be a dead miss if you had dropped a valve.

Checking the valve gap might be worth while, though. If one is way off, then I think I'd be pulling the head.

 

Sight down the tops of the valve stems.........they should all be at the same height.


Bob

 

Only have eleven stems would be a good indication of a dropped valve

 

but the system is a cross over style rocker arm. If just one valve was dropped, wouldnt it remain unnoticed untill the rocker is removed.

 

There should still be a change in valve gap.

 

Use an automotive stethoscope and you will be able to narrow down which cylinder is having problems.

 

If only 11 stems you have a huge problem... 24 valve engine??

 

If you have a loud banging, smooth idle, and this is after the turbo disintegrated, you likely have a chunk of turbine or housing in one of the cylinders bouncing around on top of a piston.

A dropped valve will lead to a miss, no exception!

 

You beat me to it.
yes, you will have significant valve play, try looking from the side. If you have a loud tap noise when running, yes you could of broken the valve inside the cyclinder or melted a piston/ring and part of it broke of inside or part of the turbo could have been sucked into the cyclinder melted and is now lodged in the piston top or cyclinder wall. Sounds like either way the head needs to come off and be reconditioned.

 

What part of the turbo blew up, Compressor of Turbine side?

For a poor mans stethoscope get a long screwdriver about 24" long, and press the butt of the handle against your ear and then probe the side of the block and valve covers with the tip of the screwdriver.
You will be amazed how easy it is to pinpoint a sound this way.

Just pay attention and don't stick it into the fan or other moving parts.
I had a rattle in an engine that would come and go for about a year only under a load, could never figure out what it was till I pulled the head and found the entire top of the piston was missing up to the top ring, there was still a chunk rattling between the piston and the head that didn’t make it out the exhaust.