Lostoned

Hello,
I recently bought a 2003 Denali. It sounds like it has a slight lope at idle and shifts around 6,000 RPM. (5.9K just before 6K technically)

So the question is: what does a bone stock 2003 LQ4 6.0 shift at?

I'm just trying to figure out if I bought a cammed truck or if that's normal for an LQ4. It looks stock but everything in the front of the engine looks new (spotless timing chain cover, new water pump)

G Atsma

LQ4 cams are so mild there should be NO lope at all. does it feel peaky at all? Like a little soggy down low, then coming on like gangbusters higher up? If so, a cam has been swapped in. And the clean front end seems to be evidence of that.

Lostoned

It's not terribly doggy down low, about the same as a 2003 Suburban (with a 5.3) that I drove recently but it does really take off as it revs up too and past 5K, - It kept pulling hard up to 5.9K and I actually let off the gas so I'm not sure how high it would actually go...just been taking it easy on it. It was definitely still in its power band at 5.9K, not like the very slow increase in RPM that you might feel when it has already past its HP peak but you still keep your foot in it....even at 5.9 it felt like there was more in it - maybe that's normal for these?

The lope "sound" could be just normal wear and tear (old plugs, coils, wires, injectors) for a 198K mile motor. I cant really tell since its got a stock exhaust (minus cats).

G Atsma

Someone might have put a mild (like maybe a 212/218 or so) cam. Might as well enjoy it!
I don't think stock LQ4's shift at 6k. Your truck has been re-calibrated in the shift dept.

Ls7colorado

iTrader: (3)

video of exhaust????

my suburban 5.3 shifts right at 6k or atleast thats where the needle is

00pooterSS

iTrader: (40)

If I remember correctly my old 04 5.3 truck shifted at/only revved out to 5500 stock

The 6.0 and 6.2's always seem a little more rumbly than the 5.3's and they have larger exhaust that's a hair louder so that may play into that cam sound.

And maybe someone that knows for sure will chime in but I think yours may be an LQ9 truck.

Ls7colorado

iTrader: (3)

00pooterSS

iTrader: (40)

Yeah I'm not sure either, the SS in 03 and up, and VHO in 04-05 got the LQ9 but I was never sure what the early denali got.

I'm starting to think it was the LQ4 though and OP is right.

04 and newer is probably right since that's when the LQ9 wasn't only in the SS anymore and started getting put in the VHO

Lostoned

Hello,
The 8th digit in the VIN code is "U" so it has (or at least had from the factory) an LQ4

I see at least one person above posted that his Suburban shifts at 6k according to the taco meter and I highly doubt I'm lucky enough to buy a truck that's had a proper cam installed...

Guess the GENIII engines just shift/rev higher then I expected. This is all new to me, last engine I built was a 72 400 small block so i got a lot of learnin to do

00pooterSS

iTrader: (40)

My 04 was tuned to rev out to 6500. Had it like that for years. A lot guys with LS motors rev them out to 7k or so

These newer ones definitely rev higher, and shift higher than the old stuff.