New GM/Chevy Owner 6.6 Gas

[GMdude2020]

Hey guys. New owner here. First time buying from GM/CHEVY. 2020 GMC 6.6 gasser. Been driving tundra whole life. Wanted a change, still have the tundra. Any idea of how reliable this truck can be or how many miles it can go? Also I heard the transmission is a reliable one for the 2020 model. Thank you. Sorry, I’m not too educated on GM products. Thank you 

[slj2008]

Welcome - My last truck 2015 , had 95,000 when traded in . Just standerd maintance . My 2012 - 130,000 - Standerd  maintance . As long as you take care of it , it will last. 

[Badbird2000]

I have a 2012 Silverado, 1500. 5.3 liter.. right now 165,000 miles. No issues, standard maintenance. 

[newdude]

6.6 is the 6.0's replacement and being a similar iron block/aluminum head construction, it should be a tank just like the 6.0 was.

 

6L90 is also a tank, and is GM's lowest warranty repaired transmission they have (aka, low issues rate).  

[GMdude2020]

Thank you guys for your knowledge and time. Been great driving it so far. Took about two days to get used to the size but it’s been great and smooth. Love the powertrain 

[wowens79]

I’m driving a 2002 with the previous 6.0 engine, and it has 242,000 miles.  It has been towed one time when a fuel pump went out at 195,000 miles.  I’ve had a couple of oil leak repaired, and a radiator.  I got 225,000 miles out of the original brake pads.

im looking at the 6.6 gasser as it’s replacement, but it still runs great, and I’m having a hard time letting go of the money to get a new one. 

[-David-]

I am looking at buying a 6.6 gas and plan on keeping the truck long for a long time.  My concern is the GDI intake valve carbon issue and how well GM has mitigated it with their built in oil/air separator in the CCV system.  Will the intake valves need periodic cleaning such as walnut blast or CRC chemical cleaning?  Does it need a catch can?  Has anyone pulled a CCV hose and seen oil passing through or has anyone borescope'd the intake after a good amount of miles?  I know the earlier German GDI engines have had the worst issues, and that other manufacturers are using a dual injection (port and direct) system.  I just wish GM would do the dual injection so I wouldn't have to worry about it.

Edited June 25, 2020 by -David-

[C/K Man]

GM has had the same basic system used on the 6.6L on the DI 5.3L and 6.2L for many years now, and I have not heard of any major issues with it.  In addition, I know GM did a lot of work managing crankcase vapor specifically on the L8T.  I don't anticipate any problems.  I could also comment that it seems to me that GM V-8's are 'tighter' than some of the competition's engines and use less oil......  

[R3mac]

We just traded our 2015 1500 LT (80k miles) on a 2020 2500HD. Pleased with the upgrade and overall feel of the truck, one of the best parts is not having the fancy engine management system from the 5.3 - cylinder cutout and descent braking. 

 

 

[Dunn]

On 7/17/2020 at 5:27 AM, R3mac said:

We just traded our 2015 1500 LT (80k miles) on a 2020 2500HD. Pleased with the upgrade and overall feel of the truck, one of the best parts is not having the fancy engine management system from the 5.3 - cylinder cutout and descent braking. 

 

 

yes i had a 19 RST and hated the auto start stop....