6.0 strange noise

[swela]

I'm new to this forum so here goes. First a little history. I have a 2006 F250 with 4" tubo back and K&N filter. The truck is used mainly as a daily driver and occasional towing. It has been very reliable until recently. Last winter the truck began to labor noticably on startup, smoke white and surge until the engine reached full operating temperature. I changed the oil and added "hot shot secret" which seemed to help some so I dismissed the problem as stiction. A couple of weeks ago the truck began running poorly with low power so I cleaned the EGR valve with no results. Took the truck to dealership and had it scanned. injectors and intake cleaned and diagnosed bad MAF. I ordered the MAF and replaced it but the truck got worse and one day would only idle with no pedal. I began to check the wiring and when I got to the ICP the truck idled up again and ran fine so I have ordered a new ICP connector. Now when the truck is under load and I really get on it I get black smoke and sometimes a strange noise that sounds like a jackhammer. It stops when I let off the throtle and shift to a lower gear. It is a manual tranny.

Many thanks to anyone who posts a respone. I'm not a hot rodder, just need a reliable truck.

[Term3]

What exactly did your EGR valve and inside your manifold look like? White smoke usually means water. Try unplugging your EGR valve and see if if still does it. You'll get a CEL because of the unplugged valve.

[rhgoody]

i am new to the sight as well, 04 6.0, i have had my truck for 4 years and i get the same (jackhammer) type of sound but not all the time. i can run 2 -4 hours on a trip with no noise, make the same 2 - 4 hour trip back two days later and it could do it a half dozen times. Always when under load and when i let off the throttle it stops, give it throttle again and sometimes does it again but most times does not.

[Tuscany]

Is this jack hammer sound happening after you let off the accelerator? Sounds to me that its the normal operation of the turbo dumping the excess boost pressure into the intake like its supposed to. I could be wrong but when mine first did that to me I was worried too and I found out its normal for it to do that.