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Frequently asked questions about cars and motorcycles

Engine Decarbonisation Instructions

Model: Volkswagen Golf Golf IV, MK 4, Golf 4 - Years 1997-2003
Part: Engine

Contamination of the combustion chamber by carbon deposits is often due to deteriorating thermodynamic conditions during fuel detonation, generally caused by a reduced ability to atomise the fuel perfectly, poor fuel quality, or a loss of efficiency from the ignition system (ignition coils, leads, and spark plugs).
In any case, it is possible to remove some of these deposits without disassembling the engine, using specific additives to add to the fuel tank or performing a cleaning directly on the intake system. In this case, you can connect a small tube to the vacuum system present on the throttle body of the intake, allowing the engine to draw in either a special cleaner (strongly recommended) or foam generated from soapy water (prefer the additive): the carbon deposits will be eliminated in gaseous form.

Updated on 13 February 2026 by ScegliAuto

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