Do You Have Carbon Buildup On Your Intake Valves?

Posted by Swedish Motors on Mar 22, 2018 3:00:28 PM

If you’re driving a late model vehicle, it's likely equipped with a direct fuel injection system.  Older vehicles with conventional fuel injection systems deliver fuel to the engine through injectors located in the intake manifold.  Newer vehicles with direct injection systems locate the fuel injectors directly in the combustion chamber of the engine; allowing the fuel to be atomized more effectively, resulting in increased fuel economy, power, and response.  The downside to this revelation in fuel injection technology is the potential for carbon-buildup to occur.  Because fuel no longer passes over and "washes" the back of the intake valves, carbon-deposits commonly form on the valve surfaces. 

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This build-up affects the way air enters the combustion chamber, causing many symptoms, including but not limited to: misfiring, rough running, hard starting, and poor fuel economy.  Worse yet, the likelihood of a burnt valve (a form of major internal engine damage) is drastically increased.  To ward off the potential for these adverse effects, it is recommended that an induction service cleaning is regularly performed to keep carbon build-up in check.  Unlike fuel injection cleaners of the past that were simply added to the fuel tank, the only way to effectively administer a cleaning agent to a directly injected vehicle is directly through intake tract of the engine. 

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Typically, this is done through a vacuum port upstream of the intake manifold, but downstream of the mass air flow sensor.  Proactively administering a proper system cleaner in this manner is an effective, necessary part of direct injection maintenance.  We recommend having the fuel induction service be performed every 30,000 miles. If your direct injection vehicle has over 100,000 miles and has not had routine induction services performed, it may require a more in-depth procedure to remediate carbon-buildup.  In this sort of case, intake manifold removal is typically required to gain access to the valves.  Then, a media blasting procedure is carried out to clean the valves individually and directly.  For questions, recommendations, or advice on your vehicles fuel injection system please contact our service department.  

Topics: auto repair

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