What's this?

[More Power]

In the WTF category, a member sent the following image and message to me asking:


Hi Jim: I removed the turbo body this morning & found the rest of this piece here is a picture: Says Dorman 5-5-5 on it looks like some kind of shim! I found it all in the 1st section of the turbo exh body so it fhad to come from the pass side I figure so I removed the valve cover & everything's there looks good! The piece is 1 9/16" round about 1/16 thick has a def lip molded into it - its steel (looks like a shim) any ideas? truck runs excellent (until turbo jammed - no misses lotyza power - 3 years ago I put new heads/inj pump / timing gears chain / dual thermo / fds cooler etc been running great till now! Im stumped - cant be a valve part no idea what it is!

http://www.thedieselpage.com/images/Turbojamb1.jpg

Any ideas?

[convert2diesel]

Dorman uses the prefix 555 for all of their expansion/freeze plugs. Should have another 2 or 3 digit number after the 555 to identify the part.

Now how it got there, well that should make for an interesting investigation :eek:

Bill

[Bigfootedalien]

the frost plug has 555-?80 stamped on it (could barely see the 80 but the ? was on the break so no idea what it is) - Was on another board on 6.5 & noone can figure it out either! 3 years ago I put new rebuilt heads on it + timeing gears etc + inj pump + dual thermo + FDS cooler + bigger exh - But noway that frost plug got from the cooling system into the cylinder areas - Myself Ive never seen that type of frost plug before (never knew they made that type) & no idea where or what make/model its even for - studyed the dorman site to no avail everything for the 6.5 has different #s! Since I got the complete piece I put it back together (turbo had 2 bent fins is all on the exh) straighten them put it back together & everythings good - no cyl misses - lotza power - good boost so Im hopin its finalized! no way Ill ever figure it out Ive had the truck 14years it has 278,000 on it! MYSTERY to say the least!

[arveetek]

Did this truck originally have EGR? I've seen people (myself included) remove the EGR valve and plug the exhaust passage with a freeze plug. Still, there's no way that I can see that the freeze plug could make its way from the intake manifold to the turbo.....

Casey

[Yukon6.2]

Could it be the waste-gate?

[Kennedy]

Frost plug

[93_Burrito]

If you have the newer style airbox (K47, with the cylindrical air filter), it may have come from the elbow between the airbox and the turbo.

There's a piece that juts out in front of the oil fill neck, which if I remember, is supposed to help reduce turbo noise. That may have been removed, and the opening in the elbow was capped off with a frost plug.

[arveetek]

If you have the newer style airbox (K47, with the cylindrical air filter), it may have come from the elbow between the airbox and the turbo.

There's a piece that juts out in front of the oil fill neck, which if I remember, is supposed to help reduce turbo noise. That may have been removed, and the opening in the elbow was capped off with a frost plug.


Ah! That sounds very logical. I did something similar when I upgraded to the round 97 air box on my 95, only I cut off part of the plastic silencer tube and glued it in.

Casey

[More Power]

One the one hand, I think it may have passed through the intake - through an intake valve to on top of the piston, then passed out the exhaust valve. The biggest problem with this theory is that the piece isn't beat up enough. It would have had to be a perfect random pass-through the combustion chamber to wind up without being really hammered.

On the other hand, if it didn't pass through a combustion chamber, how could it have gotten broken in half?

The disc that is part of the wastegate is located on the downstream side of the turbo exhaust housing. It couldn't jam the turbine.

[DmaxMaverick]

I don't think it could have passed through the intake, as Jim said, it isn't beat up enough. That leaves the exhaust as the source and path.

If it did, somehow, make it through the intake, it could be any number of things. Perhaps a spring saddle from the CDR. However, it would have had to pass through the compressor, which would have likely destroyed it.

It's a Dorman part, so it's aftermarket. It's steel, pitted, not excessively corroded (no water contact), and appears brittle. This suggests it's been in the exhaust tract for some time. The break is clean with no apparent bending, but isn't broken straight across. The impact doesn't appear to have been caused by a valve. It may have been caused by an impact with a turbine blade. In any case, there should be damage evidence, wherever it impacted.

If the engine has/had EGR, it could be a cross-bore plug (from a rebuilt head, although I don't know of an internal hole that size), or a spring saddle from an EGR valve (Dorman aftermarket?). I don't think it was an EGR defeat plug, or the engine would have run very poorly the moment it started to loosen, and I don't think it would have travelled through the system that quickly, and likely would have gone in another direction. It is curious, however, stranger things have happened.

[DieselDavy]

To find out what it is and where it could have come from, I suggest contacting Dorman to see if they would help out by telling you what it is. Maybe then we could guess where it was used.
At this point it has to be just a exercise of curiosity since it made it through without any real damage. (us engineers love these kind of exercises!)
Or you could just move on to the next fire-drill and be thankful for the relatively clean pass-through!