Alright so I was curious as to know what that meant, to over spin a turbo. Well, I dunno if my circumstances will make that an instance or not. But looking it up, I found this:

 

Overspin

Overspin occurs when the turbocharger exceeds its published "redline" RPMs. Typically, the initial damage is to bearings and seals, which allow oil to pass from the center housing into both the intake and exhaust housings; subsequent damage may result in total destruction of the turbocharger if one of the turbine wheels touches its housing. A mildly overspun turbo usually produces a tell-tale puff of smoke when the engine is first started.

 

I have seen more than once, our trucks produce a puff of smoke. Sometimes my smoke is white, sometimes black. I just associated it with the diesel. But then again, how relevant is this to us? Makes me wonder if I have overspun or of the previous owners have overspun the turbo?

Visual inspection is the best bet, if the housing and wheels are ok and no leaks then no worries, most times they self destruct and break a shaft when they go.

 

We see this probably once a month at the mine on one piece of equipment or another.

 

Most of the time it is due to a plugged air filter that causes it to over speed.

 

It confuses a lot as to how a plugged air filter can over speed a turbo so I use a vacuum cleaner as an example.

 

I ask people what happens when they plug the vacuum hose with their hand, most respond that it works harder to which I respond, does it sound like it speeds up........................blank stares and then a meak "Yes", that's because it has no air to pump thus speeds up due to a no load situation, This is the same concept as a turbo, plug the air filter it creates a vacuum condition and having nothing to pump in a virtual vacuum it overspeeds and gernades itself.

Edited January 2, 201411 yr by Wild and Free

I can see how a vacuum could cause this sort of problem...

 

I dunno if a BHAF on these trucks would allow a restriction bad enough to cause a vacuum? I would not think so..

 

So I'd have to remove the turbo to pretty much see the overall condition then?

My original bhaf got clogged with oil from the vent tube from the cad(acronym Mike)and reduced my boost pressure. That is how  noticed it. I overfilled the front diff.

My original bhaf got clogged with oil from the vent tube from the cad(acronym Mike)and reduced my boost pressure. That is how  noticed it. I overfilled the front diff.

 

Just Capitalize... Carry on...

 

My original BHAF got clogged with oil from the vent tube from the CAD (acronym Mike)and reduced my boost pressure. That is how  noticed it. I overfilled the front diff.

Just Capitalize... Carry on...

 

Will do, oh Exalted One.