Carbon Deposits Sludge, Are Very Common And Will Damage Your Engine
When deposit control additives are not adequate in gasoline, harmful carbon deposits sludge can build up inside the engine:
Fuel varnish deposits that form inside the injectors, restrict fuel delivery, causing the engine to run lean. As a result, this may cause lean misfires, rough idle, hesitation, poor fuel economy and increased HC emissions. Also a lean fuel mixture, increases the risk of detonation and preignition. So, these deposits tend to form, during the heat soak period that occurs; after the engine is shut off. As a result, the shorter the trips and the more frequent the drive cycles, the faster these deposits build up.
Deposits that form in the throttle body, can reduce airflow through the idle bypass circuit; thus affecting, idle quality and smoothness. These deposits are formed by fuel vapors, that rise up through the intake manifold.
Deposits that form on the intake valves, can restrict airflow through the intake ports; causing a loss of high-speed power. Also, the deposits can act like a sponge and momentarily; soak up fuel spray from the injectors. This disrupts the mixing of air and fuel; causing a lean fuel condition, hesitation and reduced performance. Also, deposits can cause, valve sticking and valve burning. So, intake valve deposits are formed by, normal combustion byproducts. But, can build up more rapidly; if the valve guides or seals are worn and the engine is, sucking oil down the valve guides.
Deposits that form inside the combustion chamber and on top of the pistons; increase the compression ratio of the engine. Also, raising the octane requirements of the fuel. So, too much compression, can cause spark knock (detonation), if the fuel’s octane rating isn’t high enough. Over time, detonation can damage the head gasket, piston rings and rod bearings; if it is not controlled. The knock sensor will detect detonation and tell the (PCM), to retard spark timing. This will take care of the knock, but, retarded timing, also increases fuel consumption and emissions.