Oil consumption on the new 6.6L V8 ? Owner feedback please.

[KuxW04]

Hello all, i'm starting a new thread on this.

I just put an order in to a fleet chevy dealer for a 2023 Express with a 6.6L V8.

This engine was introduced by GM io 2020, and I did some research on this engine and it seems that a lot of people are complaining that it burns oil.

It is NOT normal that a new engine burns oil, no matter what the dealer of GM tells us. They are lying.
If you understand how engines are made and how they function, you will understand that.

Any feedback from owners appreciated.

 

[bullfrog !]

Well in most cases engines do use oil. In some cases the level doesn’t change but contaminants replace the volume of the oil consumed. Most all “new” engines require a break in period to allow the piston rings to wear in and make a more complete seal. Valve stems require lubricant other wise they would wear even with advanced material being used to manufacture guides. You also have a Positive Crankcase Ventilation system which can malfunction occasionally or intermittently causing oil to go where it shouldn’t. Granted these losses of oil from the crankcase should be minimal but it occurs in almost every internal combustion engine with moving parts. Some engines are designed to use oil, antifreeze and other fluids for that matter under normal starting and running operations. Some manufacturers are simply covering their liabilities by advertising oil loss in their owners manual but some truly expect you to read them and follow their guidelines to insure you get the best service from their products. Nobody is being untruthful they are expecting you to read the manual and do your due diligence. In my 20 plus years of working in the industry I saw great improvements in engine design and development and you could infer that some engines use little or no oil between recommended oil change intervals but to imply new engines normally don’t use oil even when it is in the manufacturer’s best interest not to tell you they do and can means they are being truthful and straightforward to those buyers that do their due diligence and read the provided manufacturer’s manual and literature before buying a several thousand dollar vehicle. It seems unreasonable you would buy a vehicle that the manufacturer is stating can use oil if you want a vehicle that doesn’t. Hoping something won’t happen isn’t a very good guarantee it won’t, or as my dear old mom used to sing “why worry when you can pray!” Lol!! The original big block Chevy motors were know for using a quart of oil every 500 miles but they improved over the years, still you should check the oil as described in your owner’s manual and add as needed just like you put fuel in the gas tank before it runs out.

 

[Happy Camper]

Have you checked on enthusiast forums that specifically deal with this engine? They would usually have the best info regarding the engine, problems with it, and solutions. I would search out a couple forums with people that really know that engine, and understand it.

Obviously it's not a big enough concern to you since you did order one in your van. But while we have some excellent minds on this forum, specific concerns on an engine will be best addressed by enthusiasts.

Another thing to remember. There's always going to be more posts of people complaining than posts of everything being great.

As bullfrog said, there are a few things such as break in procedures that really make a difference in how they engine will run the rest of it's life. But there might be a few that are needed just for that engine in particular.

Let us know what you find. It'll help a lot of people moving forward. Especially the lurkers that read but don't post.

 

[KuxW04]

I can cancel the order at anytime and even when the van is ready for pickup I can change my mind, and the dealer is ok with that.

Re: oil consumption - lately some manufactureres are building pistons with weak oil rings to reduce inner friction and thus improve mpg with 0.01% That's what I am talking about. If they do it right, a new engine will not burn oil. As it ages, yes i agree it might but a brand new engine off the factory floor is not allowed to burn any oil.

I had a new subaru a few years back that burned 1quart every 1000miles, new engine. I got rid of it immediately.

I am just trying to find out if owners of this engine see oil burning issues with it in their vans, and how severe.
I am not about to buy a new van so that i can add 1qt of oil every 1000 miles...

Plus this might affect the catalytic converter, and have other negative effects on the engine.

Thanks.

 

[bullfrog !]

There are several reports of owners using 1 quart of oil every 1,000 miles with no other issues and the manufacturer has said that is within the design specifications of the engine and is acceptable oil usage. The motor is getting 14 MPG I believe which is good for a large displacement gasoline engine. If having to add a quart of oil every 1,000 miles is an issue, I know it would be for me, I would not spend the money on a new vehicle. There are plenty of older ones that are much cheaper I can afford to feed a quart of oil every 500 miles!

 

[KuxW04]

I highly doubt that any "design specifications" would allow oil usage.
This is just BS from the lawyers and PR people to say that issues will not be fixed.
I know how engineering works, and how specifications are set.
At this point of out technology, oil consumption should never be an issue really.

 

[Overland One]

It is my understanding that modern engines are run in at the factory before being installed in a vehicle. In the "old days" the new owners had to do the break in but, I just did a quick check online to confirm and several car sites said this is no longer required. They said manufacturers found that engines broken in using this controlled procedure lasted much longer than engines broken in by people driving them. Interesting one article said they do not fire them up but turn the crankshafts with hydraulics while pumping heated coolant through the block. As a former machinist, I can see how those controlled conditions would make for a much better and consistent wearing in of the new parts.

 

[Spaceman Spiff]

My knowledge/information is old as I haven't rebuilt an engine in about 25 years.
- for modified engines I would want to see about 1 qt burned per 1000 miles after break-in.
- for stock engines, ~1 qt per recommended oil change cycle.
More consumption indicates the piston ring clearances are too tight.
Less oil consumption means the rings are too loose.

The piston rings must ride on a film of oil to minimize friction and wear. That oil is left on the cylinder wall when combustion takes place and is burned. Improved metallurgy and oil chemistries will modify these numbers but the compression ring needs to ride on a film of oil.

Check with your engine manufacturer, they know how they designed the engine. GM says normal consumption “can be in the range of one quart within 2,000 miles on a properly driven and maintained vehicle.”

And of course engines with more than 75,000 miles can be expected to use more oil.

 

[bullfrog !]

Engine technology has come a long way. Used to be we “seasoned” metal by letting it rust now new coatings can use synthetic oils to increase efficiency and make rebuilds unnecessary and financially impractical, not surprising we have gone from 100,000 miles to 300,000 miles. I expect to see Toyota hydrogen powered engines go 500,000 miles regularly soon. There are already examples of their 4.7 gasoline engines going over 1,000,000 miles. Still care and maintenance to keep contamination of the air and fluids are key. One of the reasons in my opinion internal combustion engines are out of favor is the fact we stayed with a cheap dirty fuels and allowed oil companies and manufacturers to stop innovating and developing better fuels and lubricants. We got sold on cheap and dirty. Yes burning oil shouldn’t be normal and the expense has been the demise of our environment.