Originally Posted by OVERKILL
Originally Posted by supton
Originally Posted by OVERKILL
Originally Posted by supton
I believe the 4.8 had VVT in that year. Any chance it was stuck? Yeah it should have tossed a code but I'm still wondering how it could be that bad. The LS motors seemed to have pretty flat torque curves. Maybe the chain stretched, retarding the cam? That should have tossed a code too, though...
Just going by the paper numbers, the 4.8L was 295HP/305ft-lbs, so it's similar to the Pentastar, which I believe most find soft down low
And AFAIK, there's no code (pending or otherwise) for the VCT system. Others in the thread have confirmed the 4.8L isn't overly strong down low.
Poking around, I found in my files the curve for 2007+ 4.8L. I see the bump at 4k but it's not dead below that.
That's a very steep power curve
There's a 100HP difference between 3,500 and 5,500RPM! But yeah, this one is like a light switch at 4K, so I'm guessing maybe you are onto something with the VCT acting up and it just isn't bad enough to flag a code yet.
Every brand continues to advance power and efficiency … I have more efficient and less powerful vehicles like a Hybrid, a small turbo, and a Pentastar … but GM V8's keep bumping up power and mpg too. I'm fine with 6 speeds … hate CVT … and 10 speeds seem to need improvement