5 Best Penetrating Oils for Exhaust Manifold Bolts [2024 Review]

An exhaust manifold has a very important function to fulfill to make the engine work better all the time. But what happens when you don’t take good care of exhaust manifolds and the fasteners and bolts inside it gets jammed? Definitely, it’s a problematic situation for you and your engine as well. To overcome the situation you need to repair your exhaust manifold by adopting some major substances. While repairing you will see the bolts of exhaust manifolds are not working properly.

As the rusted fasteners and clogged bolts are some serious problems, without any effective substance you cannot just repair them fully. And penetrating oils are one of the effective substances that can actually work on jammed or rusted bolts magically. That’s why we thought of bringing up the best penetrating oil for exhaust manifold bolts. So you can have some insightful ideas to loosen your rusted bolts and make them workable again. Penetrating oils are so efficient that you can use them on almost all rusted metal parts of any metal-based object.

From loosening stubborn bolts to break-free the rust of the hinge of your door,quality penetrating oils for exhaust manifold have several purposes to fulfill. Besides, you will not find an easier solution than using penetrating oil. As they work faster and provide a long-term solution, you can surely adopt them. But before that insert some accurate information about some of the best penetrating oils for exhaust manifold bolts, so you get a perfect result after using it.

Best Penetrating Oils for Exhaust Manifold Bolts

Types of Penetrating Oils to Apply to Rusted Exhaust Manifold Bolts:

You will see that exhaust manifold bolts are jammed by rust in different ranges. The range of rust depends on the time, activeness, and metallic condition of exhaust manifold bolts. Examining this range, you will see different types of penetrating oils are available in the market. You should learn about these types of penetrating oils so that you can adopt one examining the condition of your exhaust manifold bolts.

a) Emulsion Penetrating Oil:

If you are searching for water-soluble oil, then this emulsion oil is your call. Water is its primal component. And that’s why this oil is greatly used for diluting in water. This way it can lower its concentration for the convenience of making the penetrating oil more powerful.

If your engine requires sensitive treatment with penetrating oil, emulsion penetrating oil is the best solution for you. Concentration under 10 percent always provides a great treatment to the exhausted manifold bolts or engine parts with a less harsh chemical reaction.

b) Straight Oil:

Petroleum Oils are mostly popular for being straight oils. Besides these petroleum oils, we witness mineral oils are also famous for being straight oils. The specialty of these straight oils is you can use them in the easiest way possible. You don’t even have to dilute these oils in water. As diluting the oil in water requires extra time and labor, you become free of such jobs while you are using straight oils.

On top of that, straight oils possess more workability. For a smooth finish and seamless surface, you can rely on this oil. Besides, it is one of the favorite oils to many professionals because they don’t have harsh or irritable components in them. Rather, their primal components are vegetable oils, sulfur, and chlorine. The combination of these components results in great lubricant.

c) Synthetic or Semi-Synthetic Penetrating Oil:

If you are searching for penetrating oils that will work on an engine that is deeply rusted, then you must look for synthetic or semi-synthetic penetrating oil. These kinds of oils carry harsh chemicals like silicone, diesters, lead, and other effective molecules. Because these components work efficiently on hardened grease and rusted layers, people mostly choose them for industrial sectors.

Another important fact about them is you need to be careful while using these types of penetrating oil. Experts suggest wearing gloves because these oils can cause serious skin irritation if they splash back your hands. However, these oils are also famous for their versatility. They can work both as fire extinguishers and coolants.

5 Best Penetrating Oils for Exhaust Manifold Bolts [2024 Review]:

Penetrating oils are the most effective lubricants that you can come across in order to have a trouble-free job. Rusted bolts and jammed metallic parts are some common diseases that any metal-based objects face if you keep them inactive for a long time.

However, as metals are always prone to get rusted, you will often have to give them proper maintenance using quality penetrating oils regularly to increase their efficiency. The penetrating oils we brought about today are so efficient and top-notch that you will instantly fall in love with them if you just try one.

1. Liquid Wrench L 106 Penetrating Oil:

Liquid Wrench L 106 Penetrating Oil

We found Liquid Wrench L 106 Penetrating oil as the best one for its immensely developed formula and superb performance in every DIY project. This oil is manufactured in a family-owned company and they are working for more than 75 years to provide superior performance in abolishing rust from bolts and other metal parts. The great news is this oil is progressing towards and very much committed to innovation.

Besides, the superiority of this oil comes when it works magically on rusted bolts, stuck nuts, and jammed locks. Its powerful formula can dissolve stubborn obstacles in a glance. The treatment it provides is so strong that even it penetrates deeply into layered grease. Also,the fast-acting and anti-seizing components in it work as soon as they get attached with rust.

On top of that, it fights with corrosion as well. By lowering surface tension, this oil works as a shield for the surface for a long period of time. This oil is perfectly well balanced with ingredients. These ingredients allow this oil to have low (almost 0 percent) viscosity and high lubricity. Besides, you will not face the negative effect of low solvency as the ingredients of this oil also control it.

You will also love the spray pattern bottle with a nozzle and hose pipe of this oil. This feature makes the appliance job easier. Moreover, as this oil carries no toxic additive, you will face a low and forgettable odor. Use this oil on a painted surface, plastic, and PVC surface without any second thought because it is safe and promising. From hinges to clamps, pipes, locks, and latches, this oil is workable almost everywhere.

Things We Liked / Pros:

  • Prestigious oil reliable for many professional DIYers for many years
  • Comes with superior workability and consistent formula
  • Can remove rust, save stuck bolts, free jammed hinges, locks, and latches
  • Works just fine on plastic-made or painted surfaces because this oil is free of abrasives
  • Easy application system with the precise sprayer, low odors, and 0 percent viscosity

Things We Didn’t Like / Cons:

  • You need to take time to make this oil work properly

2. Kano Kroil Penetrating Oil:

Kano Kroil Penetrating Oil

Our second best product is Kano Kroil Penetrating oil for its strength-bound performance and unique formula. This oil is not only capable of removing rust but also efficient enough to arrack corrosion. It also provides a money-back guarantee and thus proves its actual power. You can rely on this oil while treating sensitive metal parts as it never affects negatively them.

Besides removing rust, this oil is also promising enough to abolish carbon deposits as well. The proper lubrication power of this makes it fit for all kinds of situations. Even you can try removing gum by applying this penetrating oil. Unlike other lubricants, you will find this oil is doing the protection job too. Leaving an invisible shield behind, this oil prevents the further attack of rust and corrosion to a great extent.

On top of that, you will get your job pretty faster than other penetrating oils would provide. In fact, this oil is famous for its fast-acting formula and its deep penetrating ability. Bring any jammed fasteners and other metallic and mechanical components, this oil will free everything up. Besides, for sensitive parts and tight parts of metals, this oil is 100 percent safer.

The molecular structure of this oil is made in a way that it will first act on loosening the stubborn bond of rust and then abolish the rust at once. Also, with this oil, you can easily do the maintenance job of screws, pulleys, guns, bearings, shafts, valve guides, spindles, and so on. For faster workability and a satisfying result, trust this oil without having a second doubt.

Things We Liked:

  • Provides full workability and leaves a fine and smooth surface behind
  • Penetrates into rust and grease smoothly and loosens the bond within no time
  • Attacks corrosion with full strength and prevents it to attack furthermore
  • Perfect for tight parts of metals as it works faster and without attacking the metal parts negatively
  • Famous for providing the toughest maintenance job and its simple execution system

Things We Didn’t Like:

  • A little bit more expensive than other ordinary oils

3. Gasoila – RE06 Free All Rust Eater Deep Penetrating Oil:

Gasoila – RE06 Free All Rust Eater Deep Penetrating Oil

We chose Gasoila – RE06 Free All Rust Eater Deep Penetrating Oil as the best value penetrating oil because it carries no silicone in it and still works to maintain every metallic issue. Rather, this penetrating oil is filled with loosening agents. These agents provide immense lubricants to work significantly on rusty bolts and loosen their stubborn bond.

Among its 3-part formula, it carries 30percent of the ingredients of a rust eater. You will witness the refined structure of this oil literally eats up rust significantly. Another important fact is that this oil does not evaporate until it’s too long. Therefore, it leaves a long-term shield over the surface to maintain the maintenance job a little longer. This protective film is a great structure of this oil.

Unlike any other ordinary one, this penetrating oil has very ultra-low viscosity and is highly mobile. These special agents have made this oil work super fast and lubricate as much as possible before the time of evaporation comes. The reason for its late evaporation is this penetrating oil is not made of solvents, unlike other ordinary penetrating oils.

This oil cuts through layers of grease, rust, metallic scale instantly. Also, it can remove tar, graphite, carbon deposits, red or white lead, and so on. Moreover, this oil fixes rusted bolts, hinges, clamps, nuts, clamps, tailpipes, metallic joints, and shafts. You don’t need to trouble with any fasteners to fix these issues because this oil is alone enough. With a little amount of spraying of the oil on a particular spot, you will find the place rust-free instantly.

Things We Liked:

  • Comes enough strength to cut, remove, penetrate, and prevent rust, frozen parts, grease, tar, and so on
  • Works instantly but does not evaporate easily so the workability remains still for a longer time
  • Provides the ultimate maintenance to the bolts, clamps, nuts, screws using a limited amount of oil
  • Made with a 3-part formula of lubricant, rust eating ingredient, and rust seeking an agent
  • The ultra-low viscosity and lower solvent made this penetrating oil a quality one with a low odor

Things We Didn’t Like:

  • A little bit expensive

4. WD-40 Specialist Penetrant with Flexible Straw:

WD 40 Specialist Penetrant with Flexible Straw

WD-40 Specialist Penetrant is not a lubricant you can complain about because it comes with efficient workability and a very special feature in the whole structure. Almost every person and DIYer has heard about WD 40 because it has immense demand and at its 40 attempts, this lubricant has earned multi-functionality. The main specialty of this penetrating oil is its straw.

Because of the 8 inches long flexible straw, it makes your job easier to reach the oil to the narrowest space possible. Anywhere that is hard to reach, you can try out this WD lubricant. With its EZ-REACH straw, you can make all types of threads, crevices, and congested places lubricated by bending the straw to those places. However, the formula of this penetrating oil is worth some mentioning.

With a low odor and low viscosity, this oil has not lost its capability at all. Rather, it works super fast as soon as it contacts the surface. Speaking of the surface, you can use this oil on rubble, metal, and plastic surfaces without worrying much. From penetrating deep into rust to freeing up stuck bolts, nuts, locks, and threads, this penetrating oil has real guts to do versatile jobs. Besides, you will be astonished to see the huge capability of this oil to leave a fine layer of a shield on that particular space.

This protective layer works to prevent rust and corrosion from reforming again for a long period. Also, to dissolve tough and hardened grime and grease, there can be no alternative to WD-40. It treats metal parts and their sensitive areas and frees the locked joints with great professionalism. You will never witness WD fail any problem to solve because this brand ceaselessly tries hard to reach the ultimate point of professionalism.

Things We Liked / Pros:

  • Comes with an easy-reach spray system that covers and lubricates every narrow place including crevices, chains, and threads
  • Frees stuck or seized nuts, hinges, metal parts, and bolts of the exhaust manifold, penetrate deep into the rust
  • This oil comes with a fast-acting formula and contains the formula that offers very little odor
  • The spraying system of the penetrating oil literally saves your time, labor, and sanity
  • It provides a great treatment that it has become a favorite product for professionals

Things We Didn’t Like / Cons:

  • A little bit expensive

5. B’laster 16-PB Penetrating Catalyst:

Blaster 16 PB Penetrating Catalyst 1

Our last best pick is B’laster 16-PB Penetrating Catalyst as it is growing and developing superbly as a penetrating oil with its great properties. One of the best advantages of this oil is it is greatly available and comes with an affordable budget. However, with its amazing formula, this penetrating oil can fight rust, corrosion, grease, grime, and whatnot!

Any automotive parts, metallic parts, and exhaust systems use this penetrating oil without having the fear of having a negative effect. Besides, this oil frees the jammed locks, latches, shafts, and other metallic body parts. On top of that, some people use this oil for plumbing solutions and marine applications for real. With the low viscosity and right temperature, the oil creates no pressure on the surface.

Rather it controls the tension of the surface and does not evaporate as long as it has not done dealing with the rusty situation. You need to let this penetrating oil sit at least for 2 to 3 hours unless it is properly abolishing the rust. Also, you might need to apply a second round of this oil to have a more perfect result. So, this whole process is a little time-consuming.

But because of its late evaporation formula, the surface gets to have a very nice protective layer that will save the surface from further invade of rust. However, emitting fumes to a large extent is one of its disadvantages. You can get serious eye irritation due to this emission of fumes. Also, there is a chance that after inhaling fumes, your lungs can get badly affected too.


  • Comes with great abilities to tackle every rusty situation with its great formula
  • Breaks through rust and leaves a clean surface after abolishing the rust
  • Provides a very protective film to protect the surface on a further basis
  • Doesn’t create pressure on the bare surface and rather controls the temper of it
  • The low viscosity of the penetrating oil makes it more capable and creates less odor too


  • Emits toxic fumes both harmful for eyes and lungs
  • Very much time-consuming and a single application of this oil is not enough

How to Remove Rusted Bolts from Exhausted Manifold without Breaking?

Getting rusted nuts and bolts out of the exhaust manifold can be a very tricky job. As bolts tend to break down, you need to be very careful while you are removing rust from the exhausted manifold. You can just simply adopt the following ideas and steps that we going to tell you. Remember that, the whole process might take a long time so you need to bear with this in order to get a satisfying result.

Step One: Start with Penetrating the Rusty Surface:

You need to do this penetrating step at least some days before you remove bolts from the exhausted manifold. Apply quality penetrating oil or you can pick any of our best collections like a liquid wrench or Kano Kroil penetrating oil. But before that, remove the loosened rust using a wire brush, and then for the stubborn remainder use any of these penetrating oils. You might need to continue saturating with these oils several times for several days to get a better result.

Step Two: Let the Oil Penetrate:

To make the rusty bolts heal, you need to make sure that they get enough oil to soak. You need to let the oil penetrate deeply and smoothly into the rust of the bolts as well. And for this, you can use a machinist’s hammer and simply tap on the bolts after applying penetrating oil on them.

The hammer will create a vibration that will help to penetrate deep. Don’t hit strongly because that will break the bolt. Tighten the bolt and then loosen it again and repeat the function again and again.

Step Three: Use a Wrench or Socket:

To get into the primal job, you need to bring a quality wrench or socket. We prefer wrench mostly. Make sure the wrench is 6-point so it precisely fits the bolt. You need to keep the head of the bolts and the wrench in the same line. Otherwise, you might break the bolts. Provide a very light pressure and half-trigger. Observe the whole process so you don’t slip away from being too careful. This low process of pressuring and triggering should have the bolts removed by now.

Step Four: Use Hot Gas:

If the wrench process is still unable to remove bolts then applying a hot gas will definitely do the work. A hot gas like acetylene is enough for the job. MAP will do well too. This gas will make the nuts hot instantly and thus expand their structure. But you need to be careful because the heat should not affect the stud at all. Once you let the bolts expand, they will come off afterward. And thus you can do the job of removing bolts from the exhausted manifold without breaking.


Question: Kroil Vs ATF Acetone: Which is better?

Answer: If you want to remove rust then we would recommend you to pick Kroil over ATF acetone. ATF is not necessarily designed to remove stubborn rust but it carries components of surfactant and lubricants. But these components only work as a cleaning agent and can wash loosened rust and make the surface look good.

Question: Does FLUID FILM stop existing rust? How do you remove rusted exhaust manifold bolts with fluid film?

Answer: Fluid Film has this extraordinary feature to give proper protection to the surface from the further attack of rust. It does not carry additives to remove rust. But the best it can do is to penetrate rust and loosen its bonds.

The fluid film comes with penetrating additives. This component helps to loosen the bond of rusty bolts. So if you just let the fluid film sit on the rusty bolt and give it some time to penetrate deep then there is a chance that the rusty bolt is coming off the exhaust manifold.

Last Updated on July 3, 2024 by Rogers Weber

[As an Amazon Associate I earn from qualifying purchases.]

Add a Comment

Your email address will not be published. Required fields are marked *