Chevy 6.6 Gas Problems & Solutions With Videos : 2022

The Chevy 6.6 gas engine is used in popular Chevy and GM trucks like the 2020 Chevy Silverado HD and 2020 GMC Sierra HD.

It offers its users many benefits, from durability to its power and many more.

There are some cons to it, and we’ll discuss the Chevy 6.6 gas problems in this article.

It is important to take note of these problems before going ahead to get the engine for your truck or buy a truck that uses one.

Although the problems are not overly much, they can affect its reliability.

This article will show how reliable it is and the various problems it comes with.

How Reliable is the New 6.6 Gas Engine?

The Chevy 6.6 is considered or also known as one the GM’s fifth-generation small-block.

It was first introduced in 2020 in the new Silverado HD and Sierra HD.

It is very reliable, which is owed to the material used during production.

It is made from the best casting-iron material, guaranteeing its durability.

As reliable as it is, the first generation of the engine developed issues after 100,000 miles of use.

The issues included faults in the injector, which was the major problem faced by this engine.

It offers great driving performance and good smooth throttle control.

This power level is also enough to run your vehicle and have a good experience.

Although these problems have been tackled in newer generations, they still face other newer models’ problems.

These problems do not make them unreliable but rather tell you to pay attention to maintenance.

What are the Common Chevy 6.6 Gas Problems?

Chevy 6.6 gas problems

It is important to have knowledge about the Chevy 6.6 gas if you are thinking of getting one or a vehicle that uses one.

Some problems affect the engine’s reliability and make users regret getting it.

Some see this problem as something that could be managed, while others cannot.

Here are some of the problems associated with it:

01. Knocking Sound

This is one of the most common problems of the Chevy 6.6 v8.

It comes with a sound that users have described as a faint knocking sound that could be annoying.

It is not easy to locate where this sound is coming from.

The noise is predominant when your vehicle is put on neutral or park.

The sound does not start until the Chevy 6.6 has been used for a while, probably after 2,400 to 6,400 miles or between the first and second oil change.

Although, people suspect that the sound may be coming from the oil change.

Not all oil is suitable for this engine.

Auto professionals have advised that owners use high-grade synthetic oil; this could solve the sound problem.

This will not immediately solve the problem.

It could take 1,000 miles or more to get rid of the knocking sound completely.

02. Lack of Horsepower

The Chevy 6.6 is meant to have a horsepower of 401 and torque of 464 lb-ft.

This should be okay for an engine of this magnitude.

With this, users have often complained about the power produced by it.

When you compare this Chevy 6.6 with other prevalent ones in the market, like the Duramax engine, you would see that the 6.6 gas cannot compete with them.

Engines like the Duramax can produce up to 445 HP and torque of 910lbs-ft.

If you are looking for an engine that can produce more power, we advise that you do not get the Chevy 6.6 gas.

You can go for a big block like the Duramax.

Because the Chevy 6.6 is a small block, it will not be able to produce as much power out as the big black ones.

However, it will weigh less and reduce the weight placed on the front area of the vehicle.

03. Weak Acceleration

The 6.6L gas also has weak acceleration, which could be a major problem for people looking for a lot of power and a vehicle that can pick up speed fast.

When you compare the Chevy 6.6L gas to the diesel engine, you would see that the 6.6l does not have as much propel capacity.

Compared to others, the 6.6L does not have to portray the supposed quick acceleration that it is meant to have.

Depending on what you want to use it for will determine if you will need a quick accelerate feature or not.

04. Default in Transmitting Speed

One of the major problems is that it does not have the correct transmission to produce the vehicle’s speed.

As we know, transmission speed is an important aspect that should not be ignored.

It helps transfer power from the engine to the vehicle’s wheels.

People have complained that the 6.6l gas has a much slower speed transmission when compared to other close engines.

It comes with a 6-speed transmission which is seen as poor compared to other competing engines with 8 transmissions.

The 8 transmission has many benefits compared with the 6 transmissions.

One of the benefits is that the 8 transmission has a better fuel economy.

Many have asked whether Chevy 6.6 gasoline makes use of the 10-speed transmission, which will give it a 20% decrease in RPM during shift and offer smoother towing.

05. Towing

Another major defect that comes with the Chevy 6.6 is the lesser towing capacity.

This is owed largely to the lack of power the Chevy 6.6L cannot produce.

The towing capacity that it can produce is 14,500 lbs which is still low compared to other engines’ towing capacity.

The Duramax 6.6l turbo has about 18,500 lbs of towing capacity, making it more suitable for heavy-duty work.

With the level of power and torque, the 6.6l gas has, it will not perform as much heavy-duty and off-road duty as the others.

The Chevy 6.6L gas faces many limitations, which has led people to consider if it is worth getting.

It all still boils down to what you will be using it for.

If you are looking for an engine or vehicle used for heavy loads or heavy-duty jobs, you should skip the 6.6L gas as it will not be suitable for that.

If you are looking for a vehicle for a daily driver, the Chevy 6.6 gas could suit that specific purpose.

How Long Will a Chevy 6.6 Gas Engine Last?

The Chevy 6.6 gas is built with materials that will make it last longer than you will expect.

It is expected to last above 300,00 miles before you need any major repairs.

It is made using small cast-iron blocks, which guarantee long-lasting use.

The Chevy 6.6 gas does not need as much maintenance, repair, and parts replacement compared to other engines.

This is one of the qualities that makes it strong and desirable in the market.

You can rest assured that it will last long while giving the premium service your truck needs.

FAQs About Chevy 6.6 Gas Problems

01. Can the Chevy 6.6 gas engine get good fuel Mileage?

The Chevy 6.6 has a gas mileage of 14 mpg when driven on the highway, which people have argued is not good enough.

02. Is the new 6.6 gas engine an LS?

The new 6.6l V8 L8T engine is designed for heavy-duty trucks like the 2020 Chevy Silverado HD and 2020 GMC Sierra HD.

03. Is the new 6.6 gas engine a big block?

The new Chevy 6.6 belongs to the small, fifth-generation block group.

It is made to be durable and offers heavy-duty services.


It is important to know what the Chevy 6.6 is all about before setting off to buy one.

A good way to better understand and know if it’s the one for you is to look at the Chevy 6.6 gas problems.

The 6.6 gas offers many unique features that could be suitable for your needs, but the question is can you cope with its problems?

It comes with some issues, and we have been able to address those issues in this article.

Now that you have a better understanding of the various issues, you can now make a better decision on whether or not you would like to get one.

Do not forget that the durability and the extent to which it will perform depends on how well you maintain it.

It will be good to imbibe a good maintenance culture so that it can better serve your vehicle’s needs.

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