One by-product of combustion is carbon, the black soot that can collect and harden on the cylinder head, cylinder wall, piston, and valves. Carbon deposits in the combustion chamber can affect engine performance, resulting in higher oil consumption, engine knocking, or overheating.
Gas can go stale in as little as 30 days, use fuel treatment every time you fill your gas can to treat gas.
Demontáž součástí motoru za účelem čištění
Prvním krokem při čištění hlavy válců je získání přístupu k hlavě válců. Možná budete muset nejprve odstranit některé další součásti.
- Odpojte kabel zapalovací svíčky a zajistěte jej, vyjměte všechny baterie, pokud jsou ve výbavě.
- Remove the muffler, muffler guard, and any other components that block access to the cylinder. If you’re unsure how to remove the muffler, follow our guide.
- Šrouby hlavy válců poblíž tlumiče výfuku a výfukového otvoru mohou být delší. Aby nedošlo k záměně, připravte si šablonu. Nakreslete hrubý obrys hlavy válců na kus lepenky a pro každé místo šroubu prorazte otvory. Poté vyjměte šrouby hlavy válců a vložte je do příslušných otvorů.
- Lift off the cylinder head. If the head sticks, strike it on the side with a nylon-faced hammer. This should loosen the cylinder head enough for you to gently lift it off the engine. POZNÁMKA: Nepáčte hlavu válců. Mohlo by dojít k poškození povrchu bloku motoru nebo hlavy válců.
- Remove and discard the old head gasket.
Odstranění nahromadění uhlíku
Varování: Při odstraňování uhlíku vždy používejte ochranné brýle a rukavice odolné proti rozpouštědlům. Požádejte svého autorizovaného prodejce Briggs & Stratton, aby vám doporučil univerzální rozpouštědlo, které nepoškozuje hliníkové nebo plastové součásti a nezanechává nežádoucí zbytky.
- Place the piston at the top dead center so that the valves are closed. Then, scrape carbon gently from the cylinder head, using a wooden or plastic scraper. Take care not to dig the scraper into the aluminum. On stubborn deposits, use a putty knife, wire brush or steel wool, taking care not to bear down on the metal surfaces.
- Clean away the remaining carbon with solvent, using fine steel wool to smooth rough spots. You can also soak metal parts for up to 15 minutes to remove stubborn deposits. Scrape again, if necessary, to loosen stubborn grit. Then, clean the area thoroughly with the solvent and set the head aside. With the piston still at the top of the cylinder and the valves closed, use the same method to remove carbon deposits from the piston and the end of the cylinder.
- Turn the crankshaft to open each valve, and carefully remove any visible carbon deposits on the valves and valve seats, using only a brass wire brush. POZOR: Nedovolte, aby písek spadl do komor ventilů nebo mezi píst a stěnu válce.
- Inspect the valves and valve seats to see if they are cracked, rough or warped. Bring damaged parts to an authorized service dealer for inspection before reassembling the head.
- Using a scraper, solvent or both, remove any remaining carbon and residue left behind by the head gasket on the cylinder head and engine block. Clean the surfaces thoroughly before installing the new head gasket. Any debris or oil left on the cylinder head or engine block may prevent a tight seal and cause eventual engine damage.
Opětovná montáž hlavy válce
- Inspect the surfaces of the engine block, cylinder head and new head gasket to be sure they are clean.
- Place the new head gasket in position on the engine block. Do not use sealing compounds.
- Set the cylinder head on the head gasket, aligning the cylinder head with the gasket and the engine block.
- Remove each head bolt from its slot in the cardboard template. Then, insert the bolt in its original location, leaving it loose. Insert the other bolts in the same fashion. Make sure to attach any housings or brackets that are held in place by the head bolts.
- Hand-tighten the head bolts first, without using a wrench.
- Tighten the cylinder head bolts in increments, using a torque wrench (service part number 19393). Turn each bolt a few turns, then proceed to the next bolt until each bolt is just snug. For final tightening, use a torque wrench. Proceed in increments or roughly one-third the final torque. Consult your small engine manual for final torque specifications. Poznámka: Avoid tightening a single bolt all the way before tightening the other bolts. Uneven tightening is likely to warp the cylinder head.
VAROVÁNÍ: Always read the engine and equipment manual(s) before starting, operating, or servicing your engine or equipment to avoid personal injury or property damage. See an authorized dealer if you are unsure of any procedure or have additional questions.
In this article you will find out about GDi servicing:
- What is carbon build-up?
- Types of carbon build-up
- Signs of carbon build-up
- How to preventing carbon build-up
- How to diagnosing carbon build-up
- How to solve carbon build-up
No new technology is trouble free, and unfortunately GDi is no exception.
Here we take a look at one of the most common service issues – carbon build-up – and how you can help your customers keep it under control.
What is carbon build-up?
In a conventional port fuel or multi-point injection engine, fuel is injected into the intake port of each cylinder just upstream of the intake valve, where it mixes with the incoming air – the fuel mixture is then pulled into the engine cylinder. During this process fuel washes over the intake valves, removing any fuel that has oxidized or dirt from the intake air.
In contrast, GDi injects the fuel at high pressure, directly into the combustion chamber. The finely atomised and precisely directed fuel air mixture improves the quality of combustion, delivering more power and lower emissions. The downside, however is that fuel no longer reaches and cleans the valves, causing a build-up of deposits.
Types of carbon build-up
Overtime, these deposits will build up on the injectors and valves, causing several issues:
Vstřikovače: Carbon build-up on the tip of the injector can restrict fuel delivery causing the engine to run lean, in other words too much air and not enough fuel. This can cause several issues such as rough idle, misfires, poor fuel economy and increased emissions, as well as a greater risk of detonation and preignition. These deposits typically form in the period immediately after the engine if switched off, meaning that they will build up faster during shorter, more frequent trips.
sací ventily: Overtime, carbon can also build up on the intake valves, stopping them from opening and closing properly. This restricts air flow to the cylinders, reducing engine power and fuel economy. Although intake valve deposits are a normal by-product of combustion, they can build up quicker if the valve guides or seals are worn, or in vehicles with variable valve timing, where the valves are open for longer and are therefore exposed to more carbon particles
Signs of carbon build-up
The build-up of carbon can manifest itself in a number of ways including:
- Loss of power especially when driving at higher speed
- Špatné zrychlení
- Zastavení za studena
- Vynechává motor
- Snížená palivová účinnost
- Check engine light turned on
- Drsný běh
- Engine judder at idle speed
How to preventing carbon build-up
Whilst GDi vehicles will require a service, typically between 20 to 40,000 miles, regular maintenance in between will help prevent the accumulation of carbon:
- Change oil according to the manufacturer’s recommended change intervals and using the specified oil for optimal performance of the intake valves.
- Replace spark plugs at the recommended mileage to reduce the amount of unburned fuel in the combustion chamber.
- Use a premium quality fuel with added detergents to help keep engine parts clean from deposits.
- Add a fuel system cleaner to maintain the condition of the GDi system.
How to diagnosing carbon build-up
Unfortunately, many vehicle owners aren’t aware of the need for regular servicing until it’s too late and their check engine light comes on. In this instance there are some simple procedures you can perform to diagnose carbon build-up:
- Read any fault codes using a diagnostic tool
- Perform a vacuum test at idle and at 2000 rpm
- Check the engine blow by
- Zkontrolujte časování ventilů
- Zkontrolujte kompresi
- Conduct a cylinder leak test
How to solve carbon build-up
But don’t worry – everything’s not lost if carbon build-up is confirmed. Although there are several products that claim to remove these deposits, the only way to completely eradicate them is to disassemble the components and perform an ultrasonic clean. Using high-frequency sound waves, our range of Hartridge ultrasonic cleaning tanks, deep cleans all surfaces including hard-to-reach crevices, ensuring a more thorough and faster clean than other methods.
So, as the number of GDi engines on the roads continues to grow, so will the number of service issues related to carbon build-up. By understanding the problems caused by this, and how best to prevent them, garages can offer their customers a full GDi solution throughout the vehicle’s lifetime.
For other common GDI service issues, click here!
