LIQUI MOLY Engine Flush Reviews: Is It Worth It?

If you’re like me, you’ve probably stood in the auto parts store, staring at the shelves of engine treatments, feeling a bit overwhelmed. One product that consistently catches my eye is the LIQUI MOLY Engine Flush.

But before making a purchase, I wanted to ensure it was worth it. So, I decided to give it a try and share my experience with you. In this article, I’ll walk you through the pros and cons of LIQUI MOLY Engine Flush, compare it with other brands, and offer some maintenance tips to keep your engine in top shape.


When it comes to maintaining my car, I’m quite meticulous.

I had heard good things about LIQUI MOLY products, so I decided to give their engine flush a shot.

The promise of a cleaner, more efficient engine was too good to pass up.

  • The Application Process

Using LIQUI MOLY Engine Flush was straightforward. I poured the flush into the engine oil fill port before changing the oil, let the engine run for about 10-15 minutes at idle, and then proceeded with the oil change. The process was simple and didn’t require any special tools or skills.

The Pros of LIQUI MOLY Engine Flush

  • Improved Engine Performance

One of the first things I noticed after using LIQUI MOLY Engine Flush was an improvement in my engine’s performance. The engine ran smoother and quieter. It felt as if it had more power and was more responsive.

This was likely due to the removal of sludge and deposits that had been hindering its performance.

  • Enhanced Fuel Efficiency

After the flush, I also noticed a slight improvement in fuel efficiency. This wasn’t a dramatic change, but it was enough to be noticeable. Cleaner engines tend to run more efficiently, and I believe the LIQUI MOLY Engine Flush contributed to this improvement.

  • Prevention of Engine Damage

By removing harmful deposits and sludge, LIQUI MOLY Engine Flush helps prevent engine damage. Sludge buildup can lead to increased wear and tear, which can ultimately shorten the lifespan of your engine.

Regular use of an engine flush can help mitigate this risk.

  • Easy to Use

As I mentioned earlier, the application process was simple and didn’t require any special skills. This makes it accessible for DIY enthusiasts and those who prefer to do their own maintenance.

The Cons of LIQUI MOLY Engine Flush

Liqui Moly Pro-Line Engine Flush
  • Cost

One of the downsides of LIQUI MOLY Engine Flush is its cost. It is more expensive than some other engine flushes on the market. However, I believe the benefits it provides justify the price.

  • Not a Miracle Solution

While LIQUI MOLY Engine Flush is effective at removing sludge and deposits, it’s not a miracle solution. If your engine has severe buildup or other underlying issues, you might not see dramatic improvements. In such cases, more intensive maintenance or repairs may be necessary.

  • Potential Risks

There are some risks associated with using any engine flush, including LIQUI MOLY. If not used correctly, it can dislodge large chunks of sludge that could potentially clog oil passages. However, this risk is minimal if you follow the instructions carefully.

Maintenance Tips For A Healthy Engine

  • Regular Oil Changes

One of the best ways to keep your engine healthy is by performing regular oil changes. Fresh oil helps lubricate the engine components and prevents the buildup of sludge and deposits.

I make sure to change my oil every 3,000 to 5,000 miles, depending on the manufacturer’s recommendations.

  • Use High-Quality Oil
LiquiMoly Engine Flush

Using high-quality oil is crucial for maintaining a healthy engine.

Cheaper oils may save you money upfront, but they can lead to increased wear and tear over time.

I always opt for synthetic oils from reputable brands to ensure my engine gets the best protection.

  • Regular Use of Engine Flush

Incorporating an engine flush into your maintenance routine can help keep your engine clean and running efficiently.

I use LIQUI MOLY Engine Flush every other oil change to prevent the buildup of sludge and deposits.

  • Monitor Engine Performance

Pay attention to how your engine performs. If you notice any changes in performance, such as decreased power, increased fuel consumption, or unusual noises, it may be time for an engine flush or other maintenance.

Comparison With Other Brands


Sea Foam is another popular engine flush that many people swear by. Both LIQUI MOLY and Sea Foam are effective at cleaning engines, but there are some differences.

  • Effectiveness: In my experience, LIQUI MOLY was slightly more effective at improving engine performance and fuel efficiency.
  • Cost: Sea Foam is generally less expensive than LIQUI MOLY, making it a more budget-friendly option.
  • Ease of Use: Both products are easy to use, but I found LIQUI MOLY’s instructions to be clearer and more straightforward.

LIQUI MOLY Vs. Marvel Mystery Oil

Marvel Mystery Oil is another well-known product in the engine flush market. Here’s how it compares to LIQUI MOLY:

  • Effectiveness: Both products are effective at cleaning engines, but I found LIQUI MOLY to provide more noticeable improvements in performance.
  • Cost: Marvel Mystery Oil is usually cheaper than LIQUI MOLY, which can be a deciding factor for some.
  • Ease of Use: Marvel Mystery Oil can be used as both an engine flush and a fuel additive, providing more versatility. However, LIQUI MOLY’s dedicated engine flush formula seemed to be more effective for cleaning the engine.

Frequently Asked Questions (FAQ)

What are the disadvantages of engine flush?

One of the main disadvantages of engine flush is the potential risk of dislodging large chunks of sludge that could clog oil passages. Additionally, if not used correctly, engine flushes can cause more harm than good by disrupting the engine’s normal operation. It’s also worth noting that engine flushes are not miracle solutions and may not resolve severe engine issues.

What does LIQUI MOLY engine flush do?

LIQUI MOLY Engine Flush helps remove sludge, varnish, and other deposits from the engine’s internals. By cleaning these deposits, it can improve engine performance, enhance fuel efficiency, and reduce the risk of damage caused by sludge buildup. The product is added to the old oil before an oil change, allowed to circulate, and then drained with the used oil.

What is the best engine flush to use?

The best engine flush depends on your specific needs and preferences. LIQUI MOLY Engine Flush is highly regarded for its effectiveness and ease of use. However, other popular options include Sea Foam and Marvel Mystery Oil, which are also effective and may be more budget-friendly. Consider factors such as cost, ease of use, and personal experience when choosing an engine flush.

Does an engine flush really work?

Yes, an engine flush can work effectively to remove sludge and deposits from your engine. However, its effectiveness depends on the product used and the condition of the engine. While an engine flush can improve performance and efficiency, it’s important to follow the instructions carefully and not rely solely on the flush to resolve severe engine issues. Regular maintenance and proper care are crucial for keeping your engine in good condition.

Final Thoughts

After using LIQUI MOLY Engine Flush, I can confidently say that it has made a positive difference in my engine’s performance. The smoother operation, improved fuel efficiency, and peace of mind knowing that my engine is cleaner and less prone to damage are all worthwhile benefits.

While it may be more expensive than some other options, I believe the results justify the cost.

If you’re considering using an engine flush, I highly recommend giving LIQUI MOLY a try. Follow the instructions carefully, and you might just be surprised at the difference it can make.

Remember, regular maintenance is key to keeping your engine running smoothly, so don’t neglect those oil changes and other routine tasks.

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