8 important aspects for cleaning the oil system before changing the oil
Oil carbon and graphite as the cause of many problems
Many mechanics have not yet realised the benefits of carrying out an engine oil system clean before the oil change. But to keep an engine in optimal condition, it´s often not enough to just change the engine oil and oil filter at certain intervals. Clogged oil channels and old deposits in and on the engine components are a significant problem despite the oil change (e.g. in engines with high mileage). This is because oil carbon or graphite in the oil ducts or on components can result in serious complications.
How are deposits, oil carbon and graphite formed?
Negative influences due to the increased formation of deposits include:
- poor quality lubricant
- frequent short trips
- Predominant driving in city traffic
- excessively long oil change intervals

What are the problems of an oil change without performing an engine flush?
The problem is that the old deposits are difficult to flush out during an oil change without additives and continue to cause the associated complications despite the oil change. The impurities stick to the components or clog the oil channels and are not flushed out during the oil change.
Complications that can occur include:
- Contamination of the fresh oil
- Loss of compression and power at the cylinder walls (Fig.1)
- clattering noises at the chain tensioner
- Increased wear on rocker arm, cam and hydraulic tappet
- Damage due to overheating or running dry of the plain bearing shells (crankshaft bearings) (Fig.2 -Fig.5)
- expensive repairs
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Fig. 1 Compression | Fig. 2 Crankshaft | Fig. 3 Crankshaft | Fig. 4 Plain bearing | Fig. 5 Plain bearing shell |
How does BIZOL Pro Oil System Clean+ p91 work?
With the right products, however, these complications can be effectively controlled or even eliminated. This is why using an oil system cleaner before every oil change is absolutely necessary. BIZOL Pro Oil System Clean+ p91 is a high-quality and cost-efficient oil system cleaner for all gasoline and diesel engines, which has been developed exactly for this application and is effective in all areas of pressure lubrication.
BIZOL Pro Oil System Clean+ p91:
- lowers the viscosity in the “used” oil
- uses the “used oil” as a transport medium
- provides fresh specially developed detergents
Benefits of using BIZOL Pro Oil System Clean+ p91!
- a longer service life of the fresh oil
- improved compression and performance
- the reduction of chattering noises
- less wear at the contact points of e.g. rocker arms, cams and hydraulic tappets
- better heat dissipation and service life of plain bearing shells (crankshaft bearings)
- more cost savings because future repairs might no longer be necessary
- lower fuel consumption
- decrease of CO2 emissions
BIZOL Pro Oil System Clean+ p91 is in any case a must for the professional workshop service! Please contact us for further information!
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