How reliable is the 6.6 gasser?

[64BAwagon]

Speaking of the L8S

The rumor is that the EGR and new tuning will have a net loss of 60HP.  Thanks California 

Edited October 30, 2024 by 64BAwagon

[C/K Man]

Could be worse.  Wait 'til you see what happens to the diesels.....

[Art Baker]

2024 2500 HD 6.6 gas

this engine has burned 1 quart every 1000 miles starting at 5000

 

had It back to dealer 6 times and they have not done a thing

 

have 35,000 miles now and the oil usage is now slightly more than 1 quart per 1000 miles

[lineman1234]

Might want to go to another dealer and try different oil types, just for the heck of it. 

 

over 20,000 miles on my 2024 6.6.gasser and no notable oil use towing or empty per oil changes. 

[64BAwagon]

@lineman1234 is on the target. Try switching brands of oil and maybe go to a 10W30 depending on your usage. I know it sounds crazy but my niece had a 2.2 Ecotec that had similar consumption a while back and I told my brother to switch from M1 to Pennzoil Platinum and it dropped a lot. 

 

I only have 6k miles on mine (my 2021 with the same engine used zero oil)  but I am likely going to switch to a blend of half 5w30 and half 10W30 due to the amount of heavy towing I do, plus my truck is rarely driven in the winter AND its garaged year round. I am more concerned about it shearing down out of grade than I am cold start. 

Edited November 12, 2024 by 64BAwagon

[bruceb58]

When warm, there is little viscosity difference between a 5W30 and a 10W30. It's not much! Depends on the brand of oil. Penzoil Ultra is identical at 100°C. Mobil 1 is around 4% difference and Mobil 1 EP the 5W30 actually has more viscosity at 100°C.

Edited November 12, 2024 by bruceb58

[NaturallyAspirated]

On 10/25/2024 at 4:37 PM, 64BAwagon said:

Rumblings are that Y'all are NOT gonna like whats coming.  Thats not speculation. 

Old thread but maybe a new President could change some of this. Someone working at GM one time told me how the company gets swayed by new administrations.

[Sean Brenner]

 2025 5k miles in shop four times cracked spark plug was first. Next three are over heat issues ultimately diagnosed with a warped head due to improper torque specs. Waiting on a new head now.

[C/K Man]

https://www.freightwaves.com/news/the-day-after-speculation-abounds-on-california-trucking-regulation-with-no-acf

[Pryme]

On 1/9/2025 at 3:55 PM, Sean Brenner said:

 2025 5k miles in shop four times cracked spark plug was first. Next three are over heat issues ultimately diagnosed with a warped head due to improper torque specs. Waiting on a new head now.

This seems strange and certainly the only time I’ve heard of this. I’m sure head bolts are automated at this point in the factory. 
 

hopefully you get sorted quickly. 

[Pryme]

4 hours ago, C/K Man said:

https://www.freightwaves.com/news/the-day-after-speculation-abounds-on-california-trucking-regulation-with-no-acf

What does this article have to do with the reliability of the 6.6 gas? Mistaken sub forum?

Edited January 17, 2025 by Pryme

[C/K Man]

On 1/17/2025 at 1:29 PM, Pryme said:

What does this article have to do with the reliability of the 6.6 gas? Mistaken sub forum?

Sorry, earlier discussion on this thread about upcoming changes to the L8T 6.6L.

[lundimpact1775]

2 high pressure fuel pumps in 1 week.

 

Now I'm in my first winter with it. -27 this morning, no start. Attach jump pack, every light and radio and every electronic gadget turns on automatically. Why would I want to burn all those amps running a radio? Great design GM. 

 

Just Another turd at this point, no better than my 2016 5.3, quite possibly the world's worst truck.

 

Why can't anyone build anything to function properly anymore? 

[KARNUT]

23 minutes ago, lundimpact1775 said:

2 high pressure fuel pumps in 1 week.

 

Now I'm in my first winter with it. -27 this morning, no start. Attach jump pack, every light and radio and every electronic gadget turns on automatically. Why would I want to burn all those amps running a radio? Great design GM. 

 

Just Another turd at this point, no better than my 2016 5.3, quite possibly the world's worst truck.

 

Why can't anyone build anything to function properly anymore? 

My brother runs multiple ROW clearing crews. All trucks all specifically outfitted. He use to keep maybe two older ones as spares. Last count I saw six. I asked he said there’s two in the shop. He usually gets a new one every two years for himself. It’s been awhile. He says there’re all junk anymore. It usually electronics or with diesel emissions. He even has two. Both deleted. His boss does a spreadsheet and has a mix of brands. He’s moved away from diesel. As soon as he sees an advantage with a diesel they have an emission failure. They drive lots of miles but have slow speeds creeping up ROWs. That coupled with idle time. The diesel can’t take that anymore, emissions. They get a decent one they put miles on it. Like my brothers last one. A departure from the norm. 

[lundimpact1775]

1 hour ago, KARNUT said:

My brother runs multiple ROW clearing crews. All trucks all specifically outfitted. He use to keep maybe two older ones as spares. Last count I saw six. I asked he said there’s two in the shop. He usually gets a new one every two years for himself. It’s been awhile. He says there’re all junk anymore. It usually electronics or with diesel emissions. He even has two. Both deleted. His boss does a spreadsheet and has a mix of brands. He’s moved away from diesel. As soon as he sees an advantage with a diesel they have an emission failure. They drive lots of miles but have slow speeds creeping up ROWs. That coupled with idle time. The diesel can’t take that anymore, emissions. They get a decent one they put miles on it. Like my brothers last one. A departure from the norm. 

 

Sorry just to clarify, my 2500 is the gas L8T. And yeah it's so far the least reliable vehicle I've ever owned day in and day out.