Motor oil is a critical component of any engine. Oil is used to lubricate moving parts, which reduces friction and cuts down on the amount of heat produced by the engine. Over time, carbon soot build-up can find its way into your engine's oil supply. Simply changing the oil will not remove it, because the carbon will remain in the engine and contaminate the new oil. Fortunately, there are special cleaning products designed to tackle this carbon build-up, removing it from both the oil and the engine entirely.
Select an internal engine cleaner that will clean the carbon from inside the engine and its oil. There are several options to choose from. Auto-Rx and Sea Foam are the leading products on the market. Either will do an exceptional job of removing carbon, and each works in a similar manner.
Buy new oil and an oil filter for your car. Use a traditional Group III motor oil for this application. Even if you typically use synthetic motor oil in your engine, it is important to use a Group III oil when using the internal engine cleaner. The chemical reactions created by the cleaner will conflict with any other type of motor oil.
Remove the old oil. Park your car and activate the parking brake. Jack the car up and use jack stands to support the weight of the vehicle. Climb under the car and use a socket wrench to remove the drain plug in the bottom of the oil pan. Have a pan ready to capture the old oil. Return the drain plug after the old oil has drained completely.
Change the oil filter. Use an oil filter wrench to remove the old oil filter. Expect old oil to still be inside the filter and be careful to not spill any. Rub a small amount of new motor oil around the seal of the new oil filter, then tighten it in place with the oil filter wrench.
Add new oil. Open the bonnet of the car and open the engine crank case by removing the lid that is identified with an oil icon. Pour 5 quarts of Group III motor oil into the engine.
Add the internal engine cleaner. Pour the engine cleaner directly into the crank case with the oil. Replace the crank case cap when finished.
Complete a cleansing cycle by driving the car 2,500 miles, during which time the engine cleaner will scrub the carbon and varnish off of your engine surfaces. If you are using Sea Foam brand cleaner, drive the car aggressively, but legally, for 5 miles. White smoke will blow out of the exhaust during this time as carbon build up is atomised and expelled from the vehicle. When the white smoke stops, return to normal driving for the remainder of the cleansing cycle.
Change your oil. Continue using a conventional Group III motor oil for this application, then return to your normal oil on the next oil change. Change both the oil and filter at this time, but do not add any additional cleaners or additives.
Complete a rinse cycle by driving your car 3,000 miles. This cycle will use the clean oil to rinse away any remaining traces of carbon that were not flushed with the previous oil change.
Change your oil and filter, using whatever brand and type of oil you typically used before the cleaning process. With no carbon left in the engine, and no varnish to allow the carbon particles to bind together, your oil will remain carbon free and your engine will run cleaner.