“Mechanics don’t want you to know this”: Does this $10 car engine cleaning hack actually work?

This TikTok hack promises to clean your car engine for just $10—but does it actually work?

TikToker STONERMANE UNCUT (@stonermaneuncut) explained the hack that “mechanics don’t want you to know” in a now viral video, claiming that by using a simple product from Walmart called Sea Foam, you can clean your engine easily without taking it apart.

What does the hack involve?

In his video posted to TikTok in May 2025, @stonermaneuncut explained the hack to 3.2M viewers.

“This 10-dollar hack I’m about to show you will save you thousands in car repairs,” he claimed. “Most mechanics don’t want you to know this either, but it’s called Sea Foam Motor Treatment. You can get it at Walmart for $10.”

According to the TikToker, some of the effects of Sea Foam include: cleaning injectors, restoring horsepower, quieting noisy lifters, and getting rid of deposit buildups from engines.

“Just pour it into your gas tank or your oil crank case where you put your oil in, drive around for about 50 miles and you can tell a big difference,” he continued.

@stonermaneuncut #tiktokautocampaign #cartips ♬ original sound – STONERMANE UNCUT

Viewers flocked to the comments section to share anecdotes, with many having heard of Sea Foam before.

“Baby that’s old school. Glad you’re putting people on,” wrote Ms. Moni Q.

Crystal agreed. “I been using seafoam in everything, forever.”

“He aint lying, my 06 Nissan kept cutting off. My mechanic used that sea foam, car ran smooth.” Nina Ross commented, while someone else added that it fixed their compression problem. Others shared tips about where to apply the Sea Foam, as OP’s original advice was unclear.

“Mechanic here. Put half in your oil & half in your gas tank,” clarified Mattjones147. “’It’s a good thing to add to your maintenance but it’s not a good substitute for a clean & tune. Do it when you change your oil & fill gas.”

However not everyone was convinced, with others detailing their less-than-ideal experiences. Many claimed that Sea Foam was responsible for destroying their engines—especially in new cars—producing huge amounts of smoke, or simply not working.

“Sometimes that stuff can also ruin your engine. No drama, just saying. Happened to my friend,” commented LilMizz Sunshine.

“Seafoam ruins your spark plug in time and your fuel injectors,” claimed someone else.

What actually is Sea Foam, and what is the evidence?

According to the company’s website, Sea Foam Motor Treatment is a petroleum-based product that works on both gasoline and diesel engines. Its manufacturers claim it is 100% safe to use and doesn’t contain any harsh chemicals or detergents.

All of the uses @stonermaneuncut covered in his video are also listed here, alongside an FAQ section and dozens of positive customer testimonials. So it does look to be a legitimate, tried and tested, widely available product.

It’s also not a new hack. Sea Foam has been discussed and debated online for years, including on a post in the r/MechanicAdvice subreddit from 12 years ago. The consensus seemed to be that it was helpful, but didn’t solve problems on a broader scale beyond simple cleans, and that it was prone to causing smoke, with many posters recommending not cleaning your car in a busy neighborhood.

“It’s not a fix all. If there is something that could benefit from it it can help. It won’t miraculously fix broken items. It can clean out carbon which could be reducing your engine’s efficiency, but that’s it,” one person wrote.

The strongest anecdotal evidence comes from YouTube, where over the years several YouTubers have filmed themselves using Sea Foam in their engines to demonstrate the process and results.

In this video by ChrisFix, Chris experiments by placing a borescope camera into his cylinders before and after applying Sea Foam, this time in spray form. He then contrasts the images side by side, and there is a notable difference, with a large part of the deposit built up around the piston in particular, having been eroded by just one bottle of Sea Foam.

However, several forums also say that adding Sea Foam immediately before an oil change can pull the dirt and sludge out with the old oil. Using Sea Foam at other times could therefore pull sludge into your oil that was otherwise solidified on your engine. This could have negative impacts, like clogging sensors.

Are there other ways to achieve the same results?

Overall, the evidence was mixed, with Sea Foam seeming more of a temporary than a permanent solution.

Luckily, it isn’t the only way to prevent residue buildup in your engine. As an analysis by AAA explains, Top Tier gasoline already includes engine additives that help to prevent dirt, sludge, and residue buildup.

So, if you’re buying the best fuel—you shouldn’t need to use Sea Foam at all. It might, however, be a good substitute to use once a year if you’re living in an area where premium gasoline isn’t readily available.

Sea Foam also shouldn’t be used as a substitute for genuine maintenance. No cleaner, additive, or TikTok hack can magically fix a perished gasket or mechanically worn bearing, so use it sparingly while making sure you regularly get your car checked.

The internet is chaotic—but we’ll break it down for you in one daily email. Sign up for the Daily Dot’s newsletter here.