have a 05 6.0 its blowing air back through the air filter when turbo slows down and also puffs black smoke at higher speeds when turbo blows back through any ideas what this is and also getting about 7 mpgs

 

more info please -
miles on truck?
any mods?
CEL?
any DTC's thrown?
what are your filter change intervals?
what filters do you use?

 

66000, k&n just bought put 1000 miles no codes just did k&n from stock now noise is louder and moer noticable and alsothe turbo boost gauge fluctuates when noise is present sounds like a big continuous burp whin you let off accell pedal

 

no mods all stock

 

Most folks here will say a K&N filter offers no benefits unless you are heavily modded and it jeopardizes your turbo due to poorer filtration than stock. Also, oiled filter elements have been known to negatively affect your Mass Air Flow sensor.

The sound you hear is what folks call a "turbo fart". It is said to happen on all engines, just more pronounced when you have an aftermarket air filter. I have never heard it on my truck.

 

Other than what you have described how does the truck run and you say it is only when you let off the gas and no other time.

 

doesnt have map sensor never did it runs crappy when going about 70mph,puffing black smoke everytime it surges , it surges alot and will run out of power! its like the turbo builds up pressure and it is letting it out at all speeds.

 

who said anything about a MAP sensor?

 

You didn't remove the MAF to install your K&N did you?

From the 05 shop manual:

<TABLE cellSpacing=0 cellPadding=3 width="70%" border=1><TBODY><TR><TH vAlign=bottom>Item</TH><TH vAlign=bottom>Part Number</TH><TH vAlign=bottom>Description</TH><TR vAlign=top><TD>1 </TD><TD>9C632 </TD><TD>Turbo intake pipe-to-air cleaner clamp</TD></TR><TR vAlign=top><TD>2 </TD><TD>9B659 </TD><TD>Turbo intake pipe-to-air cleaner pipe</TD></TR><TR vAlign=top><TD>3 </TD><TD>9C632 </TD><TD>Air cleaner pipe-to-air cleaner clamp</TD></TR><TR vAlign=top><TD>4 </TD><TD>— </TD><TD>Mass air flow (MAF) electrical connector (part of 12A581)</TD></TR><TR vAlign=top><TD>5 </TD><TD>W709327 </TD><TD>MAF sensor bolts (2 required)</TD></TR><TR vAlign=top><TD>6 </TD><TD>12B579 </TD><TD>MAF sensor</TD></TR><TR vAlign=top><TD>7 </TD><TD>9643 </TD><TD>Air cleaner outlet housing</TD></TR><TR vAlign=top><TD>8 </TD><TD>9601 </TD><TD>Air cleaner element</TD></TR><TR vAlign=top><TD>9 </TD><TD>9F823 </TD><TD>Air cleaner inlet housing</TD></TR><TR vAlign=top><TD>10 </TD><TD>W527376 </TD><TD>Auxiliary air intake hose clamp</TD></TR><TR vAlign=top><TD>11 </TD><TD>9C676 </TD><TD>Auxiliary air intake hose</TD></TR></TBODY></TABLE>

 

no never had place for one have plug though

 

Me thinks you need to go back to a stock filter and replace any other parts that have been removed and start from there.

 

spelling bad maf sensor

 

was a bad turbo

 

Thanks for letting us know. The turbo sure does seem to be a pretty common problem with the 6.0L. I keep a spare in the garage.

 

Our 03 is doing pretty much the same thing & it's bone stock. Had a family member say it's the o2 sensor more than likely. What happens when one (o2 sensor) goes out? Thanks!