07 vortec max dropped valve

[otiswilsonjr3rd]

What would cause an 07 silverado vortec max with 54,000 miles to drop a valve passing a vehicle on the interstate? running diablo tune with dod disabled, with tcm set to firmest shift settings, no adjustment on shift point rpms and -20% reduction on torque control.

[mikel]

A failed valve would be my guess. Nothing in a tune that could cause that.

[otiswilsonjr3rd]

ever heard of any other 6.0 doing that is it a common problem.

[mikel]

nope...can't say I have.

[Mike_Levy]

Could be a failed spring also. Or a bad lifter thats not pumping up, or a bent pushrod, or incorrectly adjusted rockers. Could be a hundred different things. Tear it down and find out for sure.

[johan]

During testing back in 07 i had one do it on me while on the dyno, while is was just cruising too, 07 6L Vmax motor, had like 4k miles on it.
Apparently it was common for a certain production run of these.

[mikel]

Interesting...

[otiswilsonjr3rd]

its at the dealer, factory warrantys out by time but i bought an extended warranty thats supposed to cover it just waiting on a word on what they're gonna do. hoping they spring for a new motor..kinda scared of this one now

[Mike_Levy]

Make them buy you an LS3, LSA or LS9. You don't want a Vortec Max in there. A 430, 556 or 638hp motor would be much better.

[BlackZ71Silverado]

During testing back in 07 i had one do it on me while on the dyno, while is was just cruising too, 07 6L Vmax motor, had like 4k miles on it.
Apparently it was common for a certain production run of these.

By chance were these "classis" body styles with the LQ9 engine?

At our race shop we were told by our engine builder that GM fixed a problem with the release of the "L76" V-Max enigne. Not sure what the exact issue was though.

[otiswilsonjr3rd]

Mines a NBS