Can Flushing Motor Oil Harm Car Engines? Exploring the Risks and Benefits

Introduction

Motor oil is a vital component in the proper functioning of car engines. However, the concept of flushing motor oil with various solvents or 'cleaners' is a subject of debate among car enthusiasts and mechanics. This article explores the risks associated with flushing motor oil and the reasons why it can harm car engines.

Risks of Flushing Motor Oil

Flushing motor oil with solvents or cleaners can have harmful effects on your engine. The process may lead to the release and circulation of dirt particles that can get stuck in critical oil passages, oil lifters, or solenoids, such as those involved in Variable Valve Timing (VTEC) systems. This can disrupt the engine's normal operation and lead to the formation of blockages.

Another significant issue is that not all of the solvent will be removed during an oil change. Even a small amount of solvent-diluted oil can remain in the engine, which is detrimental to the protection of engine parts over the next 5000 miles or so. This can cause unnecessary wear and tear on your engine components, leading to performance degradation and potentially catastrophic engine failure.

Case Studies and Professional Opinions

Professional mechanics often advise against flushing the engine with solvents or cleaners. This is based on numerous case studies where improper flushing has led to the following:

Engine Destruction: When the solvent flushes dirt and sludge loose, these particles can enter the oil pan and plug up the oil pump. This results in a loss of oil pressure, which can quickly lead to engine failure due to rod bearing damage. Ineffective Cleanse: Even a thorough flush does not guarantee the removal of all debris. Some particles may settle in critical areas such as oil passages, causing blockages that can lead to engine failure.

Some experts suggest that regular oil changes with quality filters are an effective way to maintain engine health. Adding a quart of automatic transmission fluid to the oil can also be beneficial, as transmission fluid contains significant detergent properties that can help clean the engine.

Expert Recommendations

Based on the mileage of the engine, there may be situations where oil flushing is appropriate. However, for engines with low mileage (

Marine mechanics have had unique insights into engine flushing. In some instances, using a combination of oil and automatic transmission fluid to 'clean' the engine has been effective, but this should never be attempted by the average car owner. Such practices are not recommended due to the risks of improper technique and potential damage.

Conclusion

Flushing motor oil is a topic of concern among car owners and mechanics. While some may argue that it is beneficial, the risks associated with improper flushing far outweigh any perceived benefits. Regular oil changes with quality filters and the occasional addition of automatic transmission fluid are effective strategies to ensure engine longevity and performance. It is always best to consult a professional mechanic for guidance on the best maintenance practices for your specific vehicle.