I would appreciate your help with something that’s been debated for a long time: decarbonizing your engine. There are chemicals and procedures, like HHO, that promise to blast carbon deposits in your engine. My car has direct fuel injection and I’m told, that with enough buildup, the engine could misfire. The dealership says the best way to clean the carbon isn’t by chemicals but taking apart the engine and manually scrubbing. It wants almost $1,000 for this service. Is there any proof behind decarbonizing your engine through chemicals and is it worth the money to pay the dealer to do it? –Tony
You are correct – this is an area of debate among technicians and engineers, with the opinions of backyard mechanics thrown in.
One school of thought is that, with modern engines running as hot as they do, cleaner fuels and more sophisticated lubricants, there is no need for “decarbonizing.”
The most likely spot for carbon buildup is on the intake valves, which attract carbon atoms that find their way there from the oil pan through the PVC (Positive Crankcase Ventilation) system.
Until the advent of direct injection, fuel entered the system before the intake valve and cleaning agents contained within the fuel helped dissolve any carbon encountered on the way to the combustion chamber. But with direct injection placing the fuel “directly” into that combustion chamber, the additives have no chance to work on any carbon buildup on the intake valve. The cure is to get the engine hotter, to run it harder or change the timing of the valve action to allow more heat to reach the intake valve. Changes to PCV valve design have also come into play.
The best way to minimize or eliminate the need for injector cleaning is to use gas that contains sufficient detergent to prevent varnish buildup. Most brand-name gas has enough detergent to do this and, as a rule, premium grades contain extra cleaning agents that will usually cure this problem after a tank or two.