What Is The Best Oil Additive To Stop Engine Knocking?

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What Is The Best Oil Additive To Stop Engine Knocking?

When you hear a knocking noise from your engine the first thing most of us think is “how much is this going to cost me”?

When all major faults have been ruled out it is advisable to start with the least expensive treatment to see if this will remedy the problem.

You will often find that knocking comes from cold, hard starting caused by injector misfires. This can be a quick fix if you use the Best Oil Additive for Engine Knock.

Take a look through our reviews to find the best additive for your engine to not only stop the knocking but to also protect it and possibly enhance the performance.

Table of Contents

What Is The Best Oil Additive To Stop Engine Knocking

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1. Archoil AR9100 Oil Additive for All Vehicles

Archoil is particularly versatile as it is compatible with almost all engine types, both gas, and diesel. 

It is safe to be mixed with any synthetic oil and can be used in transmission oil as well as engine oil.

This helps to maintain many components, including gearbox, power steering, hydraulics, and differentials.

Its mild detergent formula helps to dislodge carbon deposits and sludgy build-ups, and varnishes, enabling a smoother and quieter running engine. It reduces friction and heat, other factors in a smooth engine running. 

Best feature

This additive performs well in cold weather. It keeps the engine protected and lubricated which, in turn, eliminates injector problems on cold starts. It prevents laborers from running when you least of all need it. It is the ideal additive for 6.0l and 7.3l Powerstroke cold injector issues. 

This is a high-quality oil additive that should be added at every oil change, though these won’t need to be as frequent.

It can halt corrosion in its tracks and add much longer service to your vehicle.


  • Reduces harmful carbon and sludge deposits
  • Added fuel economy
  • Suitable for gas and diesel engines
  • Ideal for cold starting and rough running problems
  • Encourages quieter, smoother running


  • Only minimal if any improvement in gas mileage noted by some users
  • ✗ Not the cheapest

2. Genuine Ford Fluid XL-3 Friction Modifier Additive

Providing your vehicle has a limited-slip differential, this could be the perfect transmission oil additive for you.

Many gear oils, both regular and synthetic, don’t contain enough lube. Use this product at an oil change and you will have thousands of miles of reduced surface friction, ie, no chatter or knocks from your differential.

Best feature

This stuff is potent and has a very strong odor. Once it is in the vehicle, the smell isn’t noticeable. Just ensure you wear gloves and be thankful for the cleverly shaped pouring spout that makes for mess-free application. 

It is designed for use in the rear differential and if you’re having some transmission skips, it could be the answer.

One full bottle could save you a fortune on costly rebuilds.

It is a crucial additive when changing rear axle fluid and will maintain the optimum performance of your vehicle, particularly when cornering.


  • Easy pour spout
  • Genuine Ford product
  • Reaches all lubed parts and reduces surface tension
  • Recommended by multiple manufacturers
  • Eliminates gear noise and chattering
  • Extends the life of diffs, clutch plates, and axels


  • Very strong odor disappears once the fluid is applied
  • Some vehicles require 2-bottles

3. Liqui Moly (20002) Cera Tec Friction Modifier

Many fuel stabilizers have a graphite base, which is a good lubricant, but not as good as molybdenum. This is the main ingredient in LiquiMoly and makes this additive exceptional at withstanding high pressures and temperatures.

It functions equally well when engine temperature drops below freezing.

Best feature

If you are being driven crazy by an annoying knock or ticking sound, try using this product. The thick concentration forms a lubricating coating on the valve train which will ensure that they run much quieter. It is also to restore the damage done by the friction of the metal to extend the life of your engine.  

It is made to very specific standards in Germany and is compatible with all major engine oils. Even though it has a slightly thicker viscosity, it won’t clog the filter system, instead just lube everything.

It works at its best on older engines or vehicles with high mileage. Apply one bottle into the tank at your next oil change and see the improvement straight away.

We love that each year a new batch is released as to when it is stood on a shelf, it can lose its potency.


  • Works with all oils and filter systems
  • Cleans residues from all valves
  • Reduces and restores friction damage
  • Quieter smoother running engine
  • Lasts for 30,000 miles


  • Specifically designed for noise reduction, not to remove debris

4. Lucas Oil 10002 Heavy Duty Oil Stabilizer

To get the best out of your vehicle you should consider using a Lucas oil stabilizer at every oil change.

It is compatible with gas and diesel engines and will blend with all grades of engine oils, including synthetic, mineral, or conventional.

It seals any cylinders that have developed a leak which slows down the rate at which you use engine oil. Added this to the fact that it raises oil pressure and increases power and mpg, and you have a very cost-effective product.

Best feature

It is hard to choose one as this is an all-around oil additive that will improve the performance of all vehicles. It is ideal to keep around if you have multiple vehicles as it is compatible with everyday rides, industrial, and farming vehicles. It will preserve the existing oil, revitalize older oil, and boost the performance of the most heavy-duty vehicle. 

Dry-starts will be a thing of the past. It will take care of smoking and knocks, and won’t create harmful sludge in your engine.

It is the best oil treatment to stop engine knocking, and to reduce friction, wear, and heat damage in all heavy-duty and high-performance engines and gearboxes.


  • Compatible with all engines and engine oils
  • Revitalises old engines
  • Reduces leaking, smoking, and knocking
  • Increases oil life by up to 50%
  • Improves power and miles to the gallon
  • Lowers engine temperature and maintains it
  • Will neither varnish nor sludge
  • Economical and great value for money
  • Maintains new engines to last longer
  • Hundreds of 5-star reviews


  • Not for use in Ford Powerstrokes

5. BG MOA Part # 110 Engine Oil Supplement

The advanced formulation of this engine supplement helps to extend the life of your engine.

As car temperatures run at ever-increasing high temperatures, BG-MOA understands that engine oil degrades at a faster rate than ever before. With degradation comes varnish, contaminants, and sludging, all of which can be very harmful and costly to an engine.

This supplement keeps the engine oil performing at its optimum best for much longer than using oil alone.

It prevents thickening and oxidization which ensures all of the vehicle’s vital components will operate smoothly and friction-free. This reduces wear and tear not only lengthens the life of the engine but it also ensures the car spends less time in the garage and therefore saves you time and money.

Best feature

This additive fortifies even the best engine oils to extend the mileage life of your vehicle. It extends the intervals at which you need to change the oil. Many users have found it is still functioning well up to 15000-miles after application.

When each of the components in the engine is allowed to move freely and perform at its best, emissions are reduced and in turn, fuel efficiency is increased.


  • Fortifies oil for extended engine life
  • Oil changes are required less often
  • All vital engine parts remain reliable
  • Stops excessive oil use
  • LSPI safe, Low-Speed Pre-Ignition
  • Prevents oxidization and sludging


  • Protects an already clean engine
  • Helps to reduce engine noise, not stop it

6. Red Line 81403 Engine Break-In Oil

If you have rebuilt an engine then you will need to take particular notice of the oil and additive you use. As you break the engine in, the camshaft and valve train will be susceptible to damage.

This is where RedLine comes in as it contains properties specific to your needs.

It contains phosphorus and zinc both properties that regulate temperature and prevent overheating. 

Best feature 

The additive protects older engine components that are starting to show signs of wear. It is one of the best oil additives for cars with high mileage, including classic and antique cars. Each component will be protected from further wear.

Give your vehicle an initial run out, let the oil start to work its magic as the engine beds in. By the second journey, it should be preventing and friction and assisting the engine in running quietly and smoothly.

The detergent compound used in the additive will keep your oil clean. You will notice this at oil changes, previously dirty and dark oil will drain and still look like new.

This is because it is less likely to oxidize and leave harmful deposits and sludge.

If you’ve rebuilt an engine, use a bottle of RedLine to protect all of your hard work.


  • Compatible with all motor oils in gas and diesel engines
  • Designed for breaking rebuilt engines in
  • Over time it reduces friction to stop knocks
  • Ideal for older, high-mileage engines
  • Perfect for vintage cars
  • Prevents overheating and regulates temperature
  • Detergents keep oil cleaner for longer
  • Smoother startup
  • Helps to seal piston rings


  • Results more noticeable after the second use

7. REV X Stiction Fix Oil Treatment

These bottles of oil treatments may be small but they pack a punch.

Once mixed with the lubricating fluid in your vehicle its microscopic particles can reach places that thicker oils can. This allows it to form a protective film over all vital engine components and prevent heat and friction damage. 

Whenever friction is prevented, noise is reduced.

Best feature

Stiction might not be a word that you are familiar with. It is a term used in the automotive industry that means static friction.

This is something that occurs in the fuel injectors and turbochargers of diesel engines.

It is often aggravated by the cold and can cause the fuel system to fail and become costly to repair.

RevX is one of the few oil additives available on the markets that directly combats these issues and therefore extends the life span of the components and makes cold starts a thing of the past.

It is a versatile additive that has multiple capabilities. You should notice an improvement in torque and horsepower as the turbocharger will always perform to its optimal capabilities.

It is a cleanser and removes harmful deposits, and prevents the existing oil from oxidizing and creating sludge.

Used at every oil change it will improve the quality and life span of the oil. You will need less frequent oil changes.


  • Compatible with all lubricating fluids in both gas and diesel engines
  • Prevents stiction from damaging fuel system parts
  • Quietens engine noise
  • Cleans varnish, sludge, and contaminants
  • Extends the life of the oil and vital engine parts
  • Environmentally friendly formula
  • Reduces friction and thermal temperatures
  • Reaches areas standard oils can’t


  • Not suitable for automatic transmission
  • More expensive
  • Not for use with limited-slip differentials

8. Lucas Oil 10278 Engine Oil

Lucas is a brand name that can be found in most busy workshops and home garages. It is a trusted and reliable brand. This oil additive is no different. 

It is compatible with all oils whether they be petroleum, synthetic, or semi-synthetic.

It is easy to use and makes a perfect blend. So perfect that Lucas suggests your engine oil will last 50% longer, which means your money stays in your pocket for longer.

Best feature

Owning an older vehicle often means lots of oil leaks as seals begin to degrade over time.

Lucas has designed a solvent-free additive that saves you time and money having them all repaired, instead, it works its way to the affected seal and seals it. And it will stay sealed until the next oil change and next application.

Cleverly, it will also prevent corrosion at a later date.

It has a honey-like viscosity, it coats all of the components and revitalizes older engines.

It settles into previously worn spaces and prevents blowby, creating less smoke and maybe giving you a few extra miles to the gallon.

It is versatile enough to be used in conjunction with other lubricants. It will safely fix leaks in automatic transmissions and hydraulic systems, just use it as a 1:10 mixture.

Top every oil change up with this additive and expect your old engine to run smoother, quieter, and last a while longer.


  • Safe for use with all lubricating oils
  • Renews and repairs worn, damaged seals
  • Up to 50% less oil consumption
  • Longer intervals between oil changes
  • Perfect for older engines, all makes, and models
  • Reduces blowby
  • Raised oil pressure, reduces noise
  • Handy pour spout


  • Stops small leaks and minimizes larger ones
  • Smaller bottles would be better

9. BestLine Premium Synthetic Engine Treatment

If you get annoyed by the frequency of oil changes, consider this oil additive.

BestLine is a tried and tested brand and very often the go-to brand for petrol-heads who know their stuff.

It is 100% synthetic which extends the life of the engine oil, making for fewer oil changes and improved running.

Best feature

It doesn’t matter if you run a gas or diesel vehicle, whether it’s a bike, tractor, or truck, this oil additive will suit it. It is compatible with all engine oils in any size or type of engine. This makes it ideal if you have more than 1 vehicle.

BestLine works by coating the engine and all of its components with a thick layer of lube. Just as most additives do, it prevents friction and overheating. However, the special formulation helps it to seek out the hottest points of the engine, the spots where it is needed more. It gives added protection in these areas and therefore, extends the engine’s life.

When there is less friction there is decreased noise, so your engine will quit sounding rough, and instead will drive much smoother.

When an engine doesn’t have to work so hard it becomes more fuel-efficient and the performance levels raise. That is exactly what you can expect from this additive.


  • 100% money-back guarantee
  • Great value for money
  • Increases gas economy
  • Cleans treats and protects all of the engine
  • Particularly good on older engines
  • Heating and friction reduced


  • Doesn’t have much overall effect on emission levels

10. Sea Foam Extreme Marine & Rv SF-16 Seafoam Liquid

If you drive an older vehicle and are struggling to find the best engine treatment for knocking, we highly recommend this.

SeaFoam is an easy-to-use additive that once it is poured in will clean and lubricate pistons, cylinders, and valves. Use it on 2 and 4-stroke, gas, or diesel and you will notice an immediate difference. Anywhere standard engine oil can get, so can this additive. It makes light work of removing deposits from, and lubricating noisy valve lifters, to quieten the engine and give you a smooth ride.

Best feature 

SeaFoam is a fuel stabilizer that can last for up to 2-years. If fuel is going to be sitting in a tank for a length of time, it is always recommended to add a stabilizer to prevent the fuel from degrading and varnishing the engine parts.

It is made from pure petroleum and as such, it will de-ice and de-gel the engine. It will control moisture levels and keep the entire fuel delivery system working at its best.

With clean injectors and carbon jets, you will notice an overall improved performance in your vehicle.


  • Contains no harsh or abrasive chemicals or detergents
  • Excels when used on older engines
  • Compatible with gas and diesel fuel systems
  • Stabilizes fuel when sat
  • A marked improvement in the performance of smaller engines


  • Less effective in ethanol gas blends

What is an Oil Additive? 

There are several types of oil additives and thickeners, thinners, and flushing agents.

If you are trying to quieten noisy lifters, you should look for a stabilizing fuel additive.  

Without compromising the quality of the engine oil they will flush out any dirt and debris that is clogging the valve train resulting in a quieter running engine.

When poured into the existing engine oil, a good fuel additive can not only improve the fuel economy and extend the engine life of your car, but it can also reduce any noises that can be heard from the engine.

Three of the main features of the best fuel additives are;

1. To reduce friction between engine components and therefore extending their life.

2. To reduce and move contaminants and sludge deposits.

3. To reduce emissions by increasing the fuel economy. 

Always ensure you have bought an additive that is compatible with the make, model, and fuel type of your engine and apply it as per the manufacturer’s instructions.

Occasionally, oil additives can contain harmful chemicals and harsh detergents that might cause more damage to your engine, always make sure the additive you choose is EPA certified.


How often should I use an oil additive? 

Every oil change is recommended.

New cars with less than 5000 miles on the clock do not need an additive, in fact, it could prove harmful.

What is engine sludge?

When engine oil degrades over time oxidation causes it to reduce and thicken. It forms a heavy, tar-like substance that we call sludge.

This settles in oil passages, the crankcase, and many other critical engine parts.

It prevents the engine from running at its best and can cause serious, expensive to repair damage.

What causes blowby?

Blowby robs the engine of vital power and happens when the compressed fuel and air mixture in the combustion chamber leak from the piston and get into the crankcase.

This allows gas pressure to build up.

What is causing my engine to knock?

When you have had all serious issues ruled out, you will possibly find that the knocking is caused by noisy lifters. As they suffer from wear and tear, come into contact with bad oil, or accumulate debris, they begin to knock. 

Valve lifters are pressure-filled cylinders that open valves using pushrods.

To work properly they must be fully lubricated at all times.

Each valve features a series of microscopic holes through which the oil passes. 

This whole process operating correctly is specifically to keep the engine running quietly.


Oil in a car keeps everything running smoothly and often standard oils come with additives already in them. 

However, over time, these may degrade and stop protecting all of the vital components of your engine. This allows friction to occur and causes harmful wear on the engine. It may also affect the ability to keep the engine cool.

By adding the best oil additive for lifter noise, you are enhancing the engine oil into the best possible protection for your engine.

This will hopefully prolong its life and give you added performance and mpg along the way. 

We hope that our best oil additive for engine knock reviews has helped you to decide on the perfect product for you.

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