It’s not too often that the easiest fix and the path of least resistance are one and the same. I mean, we’ve all been burned by at least one late-night infomercial or targeted Facebook ad, right? So it’s no surprise that the guy behind the counter trying to sell you a magic-bottled remedy for your engine issue may look like a crook to you. But the truth is sometimes engine treatments or additives can be the answer to your problem. Here are some of the most common bottled solutions on the market. Are they worth your time and money? Let’s find out.
Marvel Mystery Oil
With a rich history and enviable reputation, this elixir is one of the oldest on the market. Marvel Mystery Oil is a multi-use product, acting as a fuel additive, engine cleaner, and oil enhancer, as well as a combatant to corrosion, sludge, and wear-and-tear. It excels at cleaning and lubricating parts, and clearing out any deposits in the engine that may be causing improper operation.
As we pointed out in our piece on diagnosing engine noises, dirty lifters can cause annoying ticking sounds while driving. Marvel Mystery Oil can help clear out those deposits, alleviating some of that engine noise. Builders love to use this product, too, as it’s great for cleaning up old, dirty engine parts for reuse. With almost 100 years under its belt, this mystery oil has proved its worth. We say: Keep it on hand.
Another magical potion with an 80+year reputation, Sea Foam is a great product that, when used correctly, can produce positive results. Often seen as a competitor to Marvel Mystery Oil, it performs many of the same functions. However, while both products claim that they can be used in both oil and fuel systems, we feel Marvel Mystery Oil better suits the oil system and Sea Foam is better for the fuel system.
Sea Foam can be used to loosen up varnish and other buildups, allowing them be cleaned from the system. Better yet, as long as the seal isn’t broken on a container of Sea Foam, the product has no shelf life! We say: For a product that lasts this long and improves engine running quality and rough idling, it’s definitely a keeper.
When a serpentine belt gets worn out, it begins to squeak and squeal. Many manufacturers advertise belt dressings and conditioners as a quick fix to eliminate those awful sounds. In our opinion, if a belt is worn out and slipping, the best thing you can do is replace the belt. While these products can help reduce the squealing sounds, they are by no means a true repair. We say: This is a good product to use if you simply can’t bear the noise on your way to the parts store.
Engine Stop Noise
Much like belt conditioners, there are plenty of manufacturers who claim to have engine treatments that stop other sounds as well, like valvetrain ticking. While a product like Marvel Mystery Oil truly cleans gunked-up parts and flushes deposits, be leery of products that simply promise to dampen engine sounds. If parts are truly worn out, it doesn’t matter how clean they are, they’ll still make noise. So, if after using a proven product you still hear some alarming noises, that’s a sign that the components simply can’t do their job anymore—not that it’s time to try a sound-deadening snake oil.
By using a product that masks the sound, you are merely prolonging the inevitable. And, in truth, you can potentially cause yourself more harm. We say: Use these to save face while you save money for the new parts and repair costs you really need.
Liquid Leak Repairs
These products are very common for at-home mechanics, and it’s tough to say if they are worth their salt or not. These additives promise to stop leaks by softening and conditioning dried-out rubber seals, allowing them to safely swell back to a proper size. While this will definitely stop the leak, it’s safe to say it won’t repair the rubber seal, and that makes it a temporary fix.
We say: Eh, we don’t feel too confident about throwing liquid sealant into a cooling system or oil system to try and fix a gasket. But even if you are, only use this until you can properly repair the leak with new parts of gaskets.
Really, the trick to avoiding any snake oil is to read labels carefully. Truly, well-intentioned engine treatments won’t make wild claims on the bottle. They’ll have detailed explanations about how to properly use their products and will often have honest testimonials to back up their claims. Some may even be able to cite scientific studies proving their products’ effectiveness.
It’s worth noting that even some of the ‘iffier’ products on this list do what they say they will… to a degree. When shopping, keep in mind that engine treatments offering easier maintenance and improved longevity are not the same as engine treatments promising easy repair. Pay attention to the language used, look for honest endorsements, and consider the age of the manufacturer. Remember, if it sounds too good to be true, it probably is.