6.2L (L9H) Owners - Get all your questions answered here

[SILVERADOSC540]

Raced Guy said "Does anyone else with the 6.2 get piston slap. Mine has 28k on it now and its below 30 here and even if I let it warm up for a minute or two it sounds terrible. It remimds me of my old mans 2000 5.3 wirh 315k. I've noticed this summer it sounds like its developed lifter noise on the left side."

Have you checked your exhaust manifold bolts on the driver's side? Had the slap in my '02 2500HD, never caused a problem. Thought I had it in my '07 vmax, turned out to be a broken manifold bolt, driver's side rear. My exhaust guy told me it was common. I've heard two reasonings. He had heard that it was the iron manifold and aluminum head heating up at different rates, someone else told me it was from torque twist and short exhaust hangers. Either way it couldn't hurt to check.

[Raced Guy]

Funny you mention that, we did have that issue with my moms 03 denali. Unfortunately it is not a broken bolt/exhaust leak, i would be glad if it was !

[SILVERADOSC540]

I guess it was worth a shot. Good luck finding a good service dept. If you do I'm sure that they'll take good care of your truck.

[Likarok]

Back home from Mesa. Stored trailer and bike for return in the spring and maybe a week in Feb.

 

Wow! The 6.2 got an amazing 21mpg on the return to Canada trip. I was totally surprised.

Edited December 1, 2012 by Likarok

[badbowtie001]

I have had my new 2013 Sierra Max for about 3 weeks now and couldn't be happier with the power and performance. Today I did my first trailer towing and the torque monster just climbs those hills effortlessly! I do find I have suffered some on handling with the 2013 as compared to my 2009 which probably has to do with the smaller tires and wheels. Could anyone comment on whether they have changed to 20" tires with the NHT package and if it made any significant difference in towing?

[GMCustomerService]

Congratulations on your purchase badbowtie001. Feel free to contact me if you have any questions.

 

Tricia, GM Customer Service.

[EX-F150 owner]

I have had my new 2013 Sierra Max for about 3 weeks now and couldn't be happier with the power and performance. Today I did my first trailer towing and the torque monster just climbs those hills effortlessly! I do find I have suffered some on handling with the 2013 as compared to my 2009 which probably has to do with the smaller tires and wheels. Could anyone comment on whether they have changed to 20" tires with the NHT package and if it made any significant difference in towing?

 

Not the 20's but I did swap over to a set of the Z71 18's. When I measured the wheels they were the same overall diameter and I check my speedometer with a GPS and it was the same. No difference in performance either. I do like the older version Texas Edition 20's but they are taller and I am thinking they would not ride as soft because of the wheel size.

[wyefox]

Badbo: I swapped my 17s for factory 20s (GMC Sierra/DenaliALY 5419 with Goodyear Eagle LS-2 P275/55R20) on my 2010 NHT LT Crew. I commute about 100 miles a day. The ride is a little firmer/sportier. Overall tire size is the same so no change in speedo (per GPS) and no loss of gas mileage (I average 17-18 mpg consistently).

 

I also tow a 30' utility trailer with 6-7000 lbs for weekend high school band trips with absolutley no problems with stopping, starting or swaying.

 

Black with "4X4" decals deleted and the 20s frequently garners compliments!

[dgrinnell]

Well Ive been lurking on this site for two weeks now and thought I give my new baby some credit. On Dec 14th I traded in my 2008 Avalanche in on a New 2012 Silverado LTZ crew cab 6.2L. Man I love this truck! So much more power!! Already Ive have added a K&N drop-in, tint, hood decales, bed cover, nurf bars and weathertec floormats. Next thing I need to figure out is how to add a picture on here...

[dgrinnell]

So happy to be part of this group!

Edited January 3, 2013 by dgrinnell

[RyanbabZ71]

Welcome!

 

 

Ryan

[dgrinnell]

Are you running just the RC leveling kit for front only?

 

 

 

Well, it gets you the 6.2L, HD springs, HD locker, and 3.73 gears mainly.

 

Off GM's website.

When equipped with the awesome Max Trailering Pack, a Silverado^® Crew Cab™ can haul up to 1980 lbs.¹ of whatever it takes to get the job done, and Extended Cab models can tow up to 10,700 lbs.² The package includes the powerful Vortec^® 6.2L V8 SFI engine, heavy-duty automatic locking rear differential, Handling/Trailering Suspension Package, 9.5" rear axle, 3.73 rear axle ratio, 4 – 17" x 7.5" 6-lug aluminum wheels, P265/70R17 on-/off-road blackwall tires, fog lamps, front and rear disc brakes and Trailering Package. Standard Box only. Not available on Z71^® Off-Road Package.

¹ Maximum payload capacity includes weight of driver, passengers, optional equipment and cargo.

² Maximum trailer weight ratings are calculated assuming a properly equipped base vehicle plus driver. See dealer for details.

 

 

In order to choose this feature, you also need to add: Vortec 6.2L Variable Valve Timing V8 SFI engine -GVWR, 7300 lbs. (3311 kg) -Rear axle, 3.73 ratio17" x 7.5" 5-spoke aluminum wheelsOn-/off-road blackwall tiresAntilock 4-wheel disc brakes

 

[Robert1]

Been out of pocket for some time and recently returned from a trip through the Sierra Nevadas in November.Truck performed flawlessly. Noticed I hadn't posted up in this thread so here it is.

 

This first one is a sort of crappy shot in the garage of one of the aluminum and black enamel 6.2L badges I added some months ago.

 

 

 

 

Edited January 14, 2013 by Robert1

[Nvd]

Whats the best or a good kind of spark plugs to use in a 2010 sierra denali 6.2l? If possible some to increase MPG but overal just want some good ones in there, truck has 70,000km so wouldn't hurt to change them. I have already installed a new k&n air filter, wanna change the plugs and then the oil with mobil 1 synthetic!

 

Thanks in advance for any input on the plugs!

[Chris]

Starting in 03/04 GM trucks came with Iridium plugs which are good to 100,000 miles. When changing I would change to AC Delco iridium plugs

 

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