Is this controversial product going to damage or restore your engine?

When it comes to successful car maintenance, knowing how to keep your engine in order and running smoothly is vital. That’s why there is such a huge variety of engine oils, degreasers, sealants, cleaners, starting fluids, and antifreezes, to name just a few.

Another product which is rapidly gaining popularity among motorists is engine flush. It is far from clear, however, whether or not this product is going to help improve your engine’s performance and protect it, or if it’s going to risk doing serious damage to your engine. Does engine flush work and is it good or bad?

Why might engine flush be important?

Deposits and sludge build up in the engine for several reasons, one of the most common of which for most drivers is frequent short journeys. Taking a lot of short trips and stop and go driving is surprisingly hard on the lubricating oil because moisture that builds up in the oil during the previous rest period won’t have time to evaporate and leave the oil. This means the oil becomes diluted and increases viscosity and in the end it doesn’t lubricate the moving parts of the engine as well, leading to increased wear.

Hot and dusty environments are also hard on the engine oil as air-borne dirt particles can be taken in. Like the increased moisture, high heat breaks down the engine oil and deposits of burnt oil byproducts can build up very quickly. As it settles, all of this engine sludge can clog narrow oil passages or the screen on the oil pickup tube, restricting oil flow to vital parts of the engine, especially the upper valve train.

The real problems of an unclean engine, therefore, are a more ineffective and inefficient engine in which serious damage could be caused and which risks breaking down. 

Benefits of Engine Flush

Engine flush companies claim that ‘engine flush is specially formulated to rapidly dissolve harmful engine deposits and maintain efficient oil circulation throughout the entire engine, helping to protect vital engine wear surfaces throughout the flush’. In theory, this sounds ideal. A good engine flush can help loosen deposits and dissolve sludge, returning your engine to like-new condition. It could be, then, the first step in helping restore a previously neglected vehicle to its original condition.

Another benefit of engine flush is that it could improve your fuel economy. Contaminants circulating throughout your engine can result in oil breakdown and increased viscosity. In addition, the sludge and deposits which build up on engine parts can increase resistance, which wastes fuel. Cleaning your engine with an engine cleaner flush can help parts move more efficiently, maximizing your fuel economy and saving money.

Dangers of Engine Flush

The reason that many car manufacturers do not recommend using engine flush is because they are afraid that the chemicals may react with rubber or plastic components in the engine at the same time as they remove the dirt and sludge and cause premature engine degradation and failure.

Other car enthusiasts are concerned that engine flushes may dislodge chucks and deposits from critical arrears of the engine, causing them to move to other, even more important areas and do greater damage. Some are also convinced that an engine flush treatment may not completely dissolve the sludge and just break it up instead. The sludge may then be distributed more widely around the engine, rather than located in only certain areas, and could trigger an even greater reduction in the engine’s performance.

The real danger of using engine flushes could be when they are used in high-mileage cars. For cars that have already had a long lifespan, the engine seals may be worn and leaking. In these cases, the combination of oil and sludge is almost acting as a sealant, essentially keeping them viable and masking their true condition.

If this is the case for your engine, it is definitely not worth using an engine flush. You would find it best to leave well enough alone and not disturb the sludge that may be the only real barrier keeping oil from leaking past the seals in the older engine. If you do use it in this situation, you could end up with a leaking engine or worse. 

When Not to Flush your Engine Oil?

Flushing your engine might sound like an excellent way to maintain its health, but there are situations when it could potentially be harmful. If your car has been exhibiting signs of serious engine trouble such as knocking, tapping, or incessant overheating, an engine flush might do more harm than good. It can dislodge chunks of sludge and deposits that could clog narrow oil passages and starve engine parts of needed lubrication.

Engine flushes are also generally not recommended for high mileage vehicles that have never had an engine flush before. The build-up of sludge could be all that’s holding aged seals together, and removing that gunk could lead to leaks.

Is it worth it?

Many drivers report substantial gains when using engine flush products and swear by them, but others claim to have seen no change in performance. While engine flush cannot be a substitute for a well and regularly maintained engine that is regularly cleaned and has its oil replaced, it could be the right product for an engine that is in need of some attention.