Thought I'd post a link to the video I was referring to. The aluminum tube I was having troubles with it popping off is actually the one toward the front of the truck on the driver's side (this is also the side in the vides). The video shows the aluminum tube toward the rear of the truck disconnected.

I believe my blow-by from the oil filler is nothing like what is shown at the beginning of this video but, again, I'll check it tomorrow.

Here's the link:
Ford F450 7.3 Powerstroke Bad Cylinder - YouTube

 

OK, sorry, one more clarification... It's been a long day and I guess I'm pretty brain dead.

The tube he removed was the air intake, not another aluminum tube. My bad. Doh!

 

That video probably was a holed piston, or if you have a glow problem and use a lot of ether on a 7.3 as a cold start aid it can drop out a portion of the rings and take a chunk of the piston on down into the pan. Like Hanky said the charge air can pollute with oil from a failing turbo and cause problems. In extreme and rare cases, enough oil from a bad turbo intake side could possibly cause a run away diesel.

Make sure you have a comp gauge with a high enough range for the diesel pressures. You could make a adapter out of an old cored out glow plug if you have a way to weld/braze the fitting/s to adapt up to the gauge hose.

Could always add a temp. low pressure gauge to check the charge air pessures to see if their helping to move the connection off. If their comp reading was correct, the extra crankcase pressure and blow by makes its way through the charge air 'to a degree'.

 

Forgot,

On the blow by, depending on conditions, you shouldn't visually see much pushing out the fill neck. As a simple test, you can flip the oil fill cap flatside down with a thin piece of cardboard between the two surfaces to help with the engine vibs moving the cap. At idle, BB pressure shouldn't scoot/lift/wooble or move the cap. Although a rough idle makes it more of a challenge

 

It's pouring down rain this morning. The truck won't fit in the garage so I'm going to have wait and see if the rain stops here soon before I can do much with it.

Is the test I described where you disconnect the ICP while the truck is running to see if it is bac legitimate?

The comp gauge is for diesels and goes up to 1,000 PSI so I should be good.

 

It is..

By unplugging the ICP it defaults the system to a pre selected duty cycle. Usually it can help if you have an injector o ring bleed ect to help build HP oil for a start. Sometimes it will help with an unstable idle as well.

More than adequate on the gauge

Been an extremely dry year for us. We built our new home last year in the worst winter in five years! Figures, but their calling for some rain and snow for use in the next couple days. Gives me some time to work on my Pontiac

 

OK, just getting back to this! It's been a crazy week and I've been blocked waiting for the M10 - 1/8" NPT adapter to show up. I couldn't find one locally to save my life so had to order it online. It took forever to get here but I got it today.

I also did the unplug the ICP check. Didn't make a lick of difference in how the engine ran - at idle anyway. The first time I unplugged it the engine stumbled for a second but then picked right back up. I plugged it in and unplugged it a couple times to see if I was overlooking anything. I even had my wife stand a few feet away from the truck so she wouldn't know when I unplugged it / plugged it back in and asked her if she heard any difference in how it was idling. She couldn't tell any difference at all.

I got the air intake, turbo pipe, etc. and the valve cover off tonight. I'll be trying to do the compression check tomorrow night after work. A question I have is there is a small pool of oil at the base of the glow plug on each cylinder. I am sure that if I just unscrew the glow plug a bit of oil will drop into the cylinder. I've read that when you change injectors you really need to be careful not to get oil in the cylinder. Do I need to go to the trouble of getting a syringe/turkey baster of something and sucking the oil out before I remove the glow plugs?

Also, can I just remove the glow plugs on the one engine bank to do the compression check or do I need to remove all 8? The other (passenger side) bank is pretty well hidden - as I'm sure you know - and since the #2 cylinder is the only suspect right now I'd rather implicate or exonerate that one right now.

One last question - I'm pretty sure from the shop diagnostics (and from the unplug the ICP test) that the #2 injector and ICP are bad. If I find out the compression is good - great. I'll replace the ICP and probably all 4 injectors on that side. If the compression is bad, though, it looks like a new engine. Given that I don't have the money to do an engine right now is there any merit to replacing the ICP and injector anyway? The truck is in Houston right now but it "lives" in Colorado (we have a place there) and I need to get it back out there. On one of my trips out there later this summer hopefully I'll have the money to put into the engine then and will do it. In the meantime, if it is a bad cylinder, aside from the engine possibly just stopping on me, is there any further damage I could do if I drove it to Colorado? It will just be parked once there until such time I can do the engine. If I did drive it to CO with a bad cylinder would swapping out the ICP/injector help or hurt?

Thanks and sorry for the long post.

 

I finally got to do the compression test tonight. I'm not sure how valid the results are. The battery was pretty low but it cranked the whole time. And the compression tester wouldn't hold the pressure so I had to "eyeball" the gauge as my wife cranked the engine.

Anyway, it came out as #2 cylinder was ~100 lbs (in that neighborhood, again it's a little hard to tell with the needle jumping around). #4m #6 and #8 were all ~300 lbs.

I tested each one twice just to make sure (and #2 three times). Again, I'm not sure I was cranking with enough juice but they were all being cranked with a weak battery and the difference between #2 and the rest is worrisome.

I also noticed when I took the glow plugs out that the one in #2 cylinder looked almost brand new. It was not blackened like the others. I assume this is due to the injector not working but I've posted a picture of them in case anyone has a better explanation.

It looks pretty convincing that #2 is dead. The question now is would replacing the injector and ICP help it at all, at least temporarily, until I can get it back home (about a 1,000 mile trip) and get the money to swap out the engine?

Also, any alternatives to a whole new engine like boring/sleeving that cylinder?

 

Sorry, attached is the picture of the glow plugs. Don't know if this helps or not...

 

Very helpful to me, thank you!