Just like the title said, I just test drove an older 2007 (or 2010). Yukon Denali XL AWD with the 420 HP 6.2l all aluminum V8. I am considering purchasing this vehicle but have not yet. This vehicle had high miles (200k) but was absolutely immaculate and seemed to be well maintained. The coolant looked great, there was no apparent blow by on the engine. The transmission shifted great and it drove just like a new one (as far as ride is concerned)The price was great and the interior was way above average for a vehicle this old. The only problem was two fold. 1) there seems to be a .5-1 second delay when I depress the gas after I let off the accelerator. Spirited driving was a challenge. After all, this was a test drive. 2) When the engine would go it left me kind of surprised. This does not feel like 420 HP. This feels more like 285 HP. My FIL has a 2007 Navigator with the 5.4 that only had 300ish HP and it was much much quicker. All that to say, does this sound like a normal 6.2L from GM with 3.42 axle ratio? Could the AWD be stealing power? There are zero leaks, the frame is clean, the suspension looks and feels great. Just these two nags. Thanks!Jeremiah

I have a 6.2 in a Silverado. On the ruck boards they report GM ‘detuning’ HP and torque off the line to save the tranny. So far I love the engine, like the 5.3 need to let it sing to get max power . . . But it sounds great when singling!

I have an 11 Yukon Denali. Pretty similar to what you are talking about.While I don't feel like the rig is under powered, I don't think it feels like 400 + HP. My complaints on mine is it runs hotter than I think it should as a tow vehicle (swapping to a bigger tranny cooler next week). It has more rattles than any vehicle that I have owned (other than a 2500 Burb I bought with 120k on the clock). Interior does not compare to the top trim levels of similar year Ford or RAM. And I have had ongoing issues with the Stabilitrack - have had wheel sensors go out twice where it shuts the stability control off, and am experiencing similar problems again.When I was looking for this vehicle 3 - 4 years ago, I found TONS of Burbs/Yukons for sale with 200,000 plus miles. So they do seem to stay on the road forever - and they hold their value well.

I'd get an oil analysis done, before buying a 6.2L with that many miles. Keep in mind it's a light-duty motor with a light-duty design life (150,000). It's designed for power over longevity, and feeling sluggish could be low compression .The lag is probably just the electronic throttle body. The earlier GM ones were slow to move, relative to a mechanical throttle body, and combined with somewhat invasive torque-management, can make it feel how you describe. And a high-mile one might need a good cleaning.The AWD in that rig won't "steal" power, since it's still a mechanical coupling (clutch based engagement), and the clutches won't engage anyways unless it detects an difference between output shaft speeds.

I remember looking at a truck comparison test before purchasing my 2008 Titan. One part of the test was zero to sixty times. Theoretically the 400+ Hp chevy should have smoked the 318 HP Nissan, as their curb weights were almost the same. The Titan beat the Chevy by over 2 seconds to sixty MPH. Turns out, for fuel economy, Chevy programmed the truck not to make full power unless the accelerator had been fully depressed for two seconds. Not so good for passing maneuvers. Maybe give the motor some time and see if comes on at full boil.

Not sure what you mean by 2007 (or 2010) but they don't feel like 420hp because they aren't. 2007 was 380 and 2010 was 402.

Test Drove a 6.2l Yukon Denali | Good Sam Community

jrhanbar98
Explorer
Jun 22, 2019
I have a 6.2 in a Silverado. On the ruck boards they report GM ‘detuning’ HP and torque off the line to save the tranny. So far I love the engine, like the 5.3 need to let it sing to get max power . . . But it sounds great when singling!
Bionic_Man
Explorer
Jun 22, 2019
I have an 11 Yukon Denali. Pretty similar to what you are talking about.

While I don't feel like the rig is under powered, I don't think it feels like 400 + HP.

My complaints on mine is it runs hotter than I think it should as a tow vehicle (swapping to a bigger tranny cooler next week). It has more rattles than any vehicle that I have owned (other than a 2500 Burb I bought with 120k on the clock). Interior does not compare to the top trim levels of similar year Ford or RAM. And I have had ongoing issues with the Stabilitrack - have had wheel sensors go out twice where it shuts the stability control off, and am experiencing similar problems again.

When I was looking for this vehicle 3 - 4 years ago, I found TONS of Burbs/Yukons for sale with 200,000 plus miles. So they do seem to stay on the road forever - and they hold their value well.
carringb
Explorer
Jun 22, 2019
I'd get an oil analysis done, before buying a 6.2L with that many miles. Keep in mind it's a light-duty motor with a light-duty design life (150,000). It's designed for power over longevity, and feeling sluggish could be low compression .

The lag is probably just the electronic throttle body. The earlier GM ones were slow to move, relative to a mechanical throttle body, and combined with somewhat invasive torque-management, can make it feel how you describe. And a high-mile one might need a good cleaning.

The AWD in that rig won't "steal" power, since it's still a mechanical coupling (clutch based engagement), and the clutches won't engage anyways unless it detects an difference between output shaft speeds.
Durb
Explorer
Jun 23, 2019
I remember looking at a truck comparison test before purchasing my 2008 Titan. One part of the test was zero to sixty times. Theoretically the 400+ Hp chevy should have smoked the 318 HP Nissan, as their curb weights were almost the same. The Titan beat the Chevy by over 2 seconds to sixty MPH. Turns out, for fuel economy, Chevy programmed the truck not to make full power unless the accelerator had been fully depressed for two seconds. Not so good for passing maneuvers. Maybe give the motor some time and see if comes on at full boil.
mooky_stinks
Explorer
Jun 23, 2019
Not sure what you mean by 2007 (or 2010) but they don't feel like 420hp because they aren't. 2007 was 380 and 2010 was 402.
APT
Explorer
Jun 23, 2019
If you get a GM, budget for a Black Blear Tuner to change the throttle response and shift behavior so that it feels like 420hp.
jerem0621
Explorer II
Jun 23, 2019
mooky stinks wrote:
Not sure what you mean by 2007 (or 2010) but they don't feel like 420hp because they aren't. 2007 was 380 and 2010 was 402.

I couldn’t remember the model year. It was a 2010 and you were right I was off by 17 whole HP.

You didn’t get the point of my question....regardless of those few HP I was off the truck WAS A SLUG compared to the higher HP ratings.

Everyone, Thank you for your responses. I’d like to buy it but still considering and your responses help play into my decision.

Thanks!

Jeremiah
colliehauler
Explorer III
Jun 23, 2019
If it was a slug solo what will it be like towing?
VernDiesel
Explorer
Jun 25, 2019
Buy it then get the black bear tuner to change the throttle response. Magically you will realize you did buy a 400 HP truck. Then go put another 100k on it.
falconbrother
Explorer II
Jun 26, 2019
I'm a shade tree mechanic, brakes, water pumps, various things like that I can do. For the symptoms you describe I would totally take it to a professional shop and let them look at it before I dropped real money on it. I like my 5.3 Suburban, mostly because I know it. Don't end up with regrets, let a local shop do a compression test, etc..