Out of curiosity, lets say my truck was hammering away like it did this past summer.....fortunately it has stopped but if it cam back....could I simply pull a glow plug out of the head and look at the piston with a bore scope? This would tell me real quick if I have any marks on the piston.

I have not seen a 6.7 apart but I assume the Glow plug is located in the center of the head over each cylinder correct? I also assume (never seen one) that the glow plug is big enough to get a bore scope end through?

Just a though as I have used this in gas engine many times to inspect the cylinder walls and top of pistons.

I never let me truck hammer real bad as I would down shift quickly and stopped but if it starts again I may be inclined to let it make a little noise and then inspect.

Thoughts?

 

I guarantee that if your pistons are hitting the valves you will see the evidence with a bore scope. It's going to leave a mark.
However, the marks are going to be the least of your concerns.

 

Well thats my point.....I am surprised we have not heard any reports of dealers or anyone doing this. Looking at the piston with a bore cope should only take an hour total and you would know real quick if you have interference. Even if the contact was just barely there it should still leave a mark. To me this makes sense prior to a head tear down. I don't know, maybe it has been done but no one has reported it.

 

The glow plugs are located basically right under the fuel common rails, a little more on the outboard side of the cylinder heads. On the passenger side, which is the side in question, the EGR cooler would probably have to be removed for access. I think you might be able to snake a scope in there.

 

I though it was the drivers side bank?
I guess I had that wrong.

 

Nope you are correct. My mistake. Indeed it is the left side that supplies fuel for regeneration, while the right side does not for the very reason of the EGR cooler function.

 

Dealers have already been doing head swaps on this very issue, so quite a few techs have stared directly at the pistons and valves. No valve to piston contact, no damage.


If the valve hits the piston, there's always evidence.

 

I really wish we could find a tech that has a truck in the shop for this issue and has some pictures of the pistons and heads as soon as they are pulled off. You would think there would be some pics floating around there somewhere.

 

If there was contact, there would be pictures. Nothing to see, nothing to photograph.

 

I go back as far as oil bath air cleaners and generators. Manual shut off valves for the heater core.

So as far as I know the basic principles remain the same. If a piston goes to TDC and a valve is open then you have contact, followed by a big bill.

Don't think that has changed.

 

Now that we are closer to the end of the first quarter, did release the promised software update?

 

I haven't seen anything... and I check these forums all the time.

 

No, nothing released yet. End of the month is the earliest I would expect.

 

And I am sure that the EPA will take a very hard look at any emissions software changes after what VW pulled.