The cylinder head is a fundamental part of the vehicle engine and plays a decisive role in the internal combustion process; manages the supply of the mixture of air and fuel, as well as controls the expulsion of exhaust gases. Although it is made up of numerous small components, its cleaning is quite simple; you just have to make sure you disassemble it completely and be careful not to damage the surface during the process.
Steps
Method 1 of 3: Preparation
Step 1. Gather all the necessary equipment
Before you begin, you need to get the tools and equipment you need to thoroughly clean the cylinder head. Most of these items are available at home, although you need to use a chemical brake cleaner or mechanical parts cleaner that you need to buy at the auto parts store. You must also have access to hot water in which to soak the cylinder covers. Here's what you need to muster before starting the job:
- Cleaner for brakes or for mechanical parts;
- Compressed air can or compressor;
- Two large bowls or buckets;
- Rags or kitchen paper
- Plastic scraper.
Step 2. Verify that the cylinder head is completely disassembled
When carefully assembled, this element contains numerous small parts that you need to remove to begin the cleaning job. Most cylinder heads have one or two camshafts, intake and exhaust valves with their mounts, and probably some starter components, such as spark plugs or ignition coils. All of these items should be removed and put away in a safe place as you proceed with the cleaning.
- Proceed with great care when removing the valve cover located on the top, to avoid deforming it; first, loosen all the bolts and then proceed to unscrew them completely.
- Be careful not to lose any small pieces you remove.
- Some components need to be pushed out of their housing using a press; if you don't have this tool, you need to rent one or ask your trusted mechanic to help you.
Step 3. Put on the appropriate protective gear
Cleaning this part of the engine involves the use of chemicals that are dangerous to the eyes and that could irritate the skin due to prolonged contact. To protect yourself, make sure you are using the right devices at all times throughout the process.
- You should always keep safety glasses or a face mask on while using chemical cleaners.
- Chemical resistant gloves are also essential to prevent your hands from becoming irritated by exposure to brake cleaner or mechanical parts. If you opt for a product that does not need to be sprayed but poured into a basin, you should wear gloves that cover the entire forearm and up to the elbow if possible.
Step 4. Determine what material the head is made of
Most are made of iron or aluminum alloy. Both metals have advantages and disadvantages in terms of vehicle durability and performance, but in this case the most important detail to consider is that aluminum is a softer material and is more susceptible to damage during cleaning. To understand which metal your engine is made of, consult the car's user and maintenance manual or use these criteria:
- Those of aluminum are lighter and lighter than those of iron; if they are light gray, they are clearly of aluminum, while the darker ones are composed of a ferrous alloy;
- Iron is subject to rust, but not aluminum; if you notice traces of oxidation, it is certainly iron;
- The magnet does not stick to aluminum, but adheres to iron.
Method 2 of 3: Cleaning
Step 1. Use a plastic scraper to peel off the gasket residue
This element allows to create a hermetic seal between the cylinder head and the engine block; it is very likely that there are some fragments left on the cylinder cover, which you must carefully remove using the scraper. Proceed with extreme caution to avoid scratching or damaging the contact surface where the gasket is installed. Any scratch or notch can cause leaks and prevent a hermetic seal once the motor is assembled.
- Do not use a metal tool or other tools that can easily damage the surface of the component you are cleaning.
- Make sure you have removed any remnants of the old gasket to allow for a perfect fit of the parts once the cylinder head has been reassembled.
Step 2. Put it in the basin
After removing the gasket, transfer the cylinder head to the first container. If you have decided to use a liquid detergent, pour it into the container to be able to clean; if you have opted for a spray product, you do not have to fill the bowl.
- Be very careful when moving the component, as there are nozzles and nozzles of the vacuum ducts sticking out of the surface that can be damaged if you hit them against tables or walls.
- Depending on the specific situation, help may be needed to put the item in and out of the trays as it is quite heavy.
Step 3. Use a mechanical parts cleaner and a rag to scrub the cylinder head
Use the product of your choice and clean every portion you can reach. Pour or spray the cleaner on the areas you don't have access to. the solution should be able to dissolve most of the carbon deposits and burnt oil, although some "elbow grease" is needed elsewhere.
- Do not use a steel bristle brush or other tools that could damage the mating surfaces of the cylinder head.
- Take your time to clean any crevices and hidden nooks and crannies.
Step 4. Fill a second basin with hot water
After scrubbing the piece thoroughly, pour hot water into the second bowl. Make sure that the latter is deep enough to accommodate all the component and add enough liquid to completely submerge it; it is advisable to carry out this phase outdoors or in a room with a drain.
- Make sure the bowl is large enough to submerge the entire head.
- Use hot or very hot water to fill the container.
Step 5. Soak the head
Proceed gently; the water reaches all those corners that you did not have access to with the rag and removes the detergent you used in the previous step. The aluminum heads can be damaged by prolonged exposure to caustic substances present in chemical products, it is therefore essential to proceed with rinsing.
- Let it soak for a few minutes.
- If you can't completely submerge it, add more liquid.
Step 6. Remove it from the bowl and use a rag to dry it
After waiting a few minutes, gently lift it from the water and place it on a stable workbench; use a clean rag to remove as much moisture as possible, making sure to remove any stagnant water that may have collected in the cracks.
- You can't completely dry the head with a cloth, but removing most of the water speeds up the process.
- Do not reuse the cloth soiled with detergent, make sure the cloth is new and clean.
Step 7. Use a pressure washer
If you have this specific machine for mechanical parts available, you can use it to clean the external part of the head and the accessible areas of the internal one more efficiently. Just like the manual procedure, even the one with the pressure washer does not allow thorough washing of the cracks that are difficult to reach, but significantly reduces the effort required to clean the rest of the component.
- You can rent this machine at the hardware store or at a mechanical workshop.
- Smaller models are available at auto parts stores, although they are prohibitively expensive if you don't intend to amortize it by washing other parts as well.
Step 8. Use a hot wash tub
It represents another specific tool that is used to thoroughly clean the mechanical elements. In practice it is a very large tank in which caustic chemical detergents are poured which reach all the internal and external surfaces of the head; it saves a lot of work compared to other methods, as you just put the component in the container and start the process.
- Hot wash tubs are available at workshops and mechanical supply stores.
- You can subject the headboard to this process after washing it by hand to make sure it is as clean as possible.
Method 3 of 3: Drying and Storage
Step 1. Use compressed air to remove water from hard-to-reach areas
After wiping the outer surface with a rag, take a can of compressed air or a compressor to treat all the narrow gaps and openings in the engine component. By doing this, you dry the metal, eliminate the dust and all the other residues that have fallen into the head during the washing phase.
- Direct the airflow into each opening to make sure no moisture or foreign objects remain.
- It also checks that there is no type of residue on the piece, since even the slightest amount of dust can damage it after installation.
Step 2. Wait for it to dry completely
Leave it on the workbench and lay some sheets of kitchen paper on top to prevent dust from falling inside and accumulating on freshly washed surfaces.
Do not store it while it is still damp; in particular the iron models can oxidize and rust
Step 3. Inspect it for damage or defects
Before reassembling it or storing it, check that it has not been damaged during washing and that there is no previous damage. Any crack in the surface compromises the proper functioning of the component, while imperfections, scratches or streaks on the coupling area (between the cylinder head and the motor body) prevent the gasket from creating a hermetic seal. If you notice this kind of damage, you may be able to get the part repaired, but it is much more likely that you will need to buy a new one.
- If you notice persistent traces of dirt during the inspection, repeat the entire washing procedure.
- Remember that it is better to be safe than sorry; assembling and installing the engine head takes a long time. If you are concerned that it is damaged, bring it to the attention of an experienced mechanic.
Step 4. Grease it and put it in a bag before putting it away
If you intend to store it for a while before mounting it back on the engine, you must take precautions to protect it from debris and oxidation; sprinkle a light layer of WD40 before wrapping everything in a sturdy plastic bag.
- Seal the container with zip tie or staples to make sure dust can't accidentally get in.
- Put the cylinder head in a safe place where it cannot be damaged.
