Best Engine Flushes of 2025

"I recently tried the Liqui Moly Engine Flush on my 2005 Honda Element with 156,000 miles. I've always maintained my oil changes, so I wasn't too concerned about sludge. After running the flush in the old oil, and then using cheaper oil to rinse, the car now idles much quieter and accelerates more smoothly. No signs of smoking or leaking so far, but I'll keep you updated if anything changes."

"This was my first experience with an engine flush, specifically on my 2006 Ford. I noticed a significant change; the smoke has reduced, and my fuel efficiency has definitely improved. Even the clicking noise from the valves has disappeared for now. I'm really pleased with the results!"

"After using the Liqui Moly 2037 Pro-Line Engine Flush, I was genuinely impressed. It removed sludge and deposits effectively, enhancing my engine's performance and noise levels. The application was straightforward, and I could feel the difference after just one use. It’s a solid investment for anyone wanting to extend their engine's lifespan. Highly recommend!"

"I can confidently say this engine flush is the most amazing product I've encountered in my extensive automotive career! It worked wonders in my 2004 GMC Sierra, making it run like new after 225,000 miles. Seeing is believing—the oil I drained post-flush was completely black, while the flush itself was nearly clear!"

"After using this product, my 2010 Land Rover LR2 went from sounding like a diesel truck to running smoothly like it did when I first got it. I did another flush three months later, and now it feels like a brand-new engine!"

"I recently bought a used John Deere lawn tractor, and after adding the recommended amount of flush, the oil that came out looked like yesterday's food! I highly recommend this product, but be cautious not to run it under load for too long."

"I used this on a high mileage Nissan, and it looked a lot cleaner after the first oil change. The engine felt smoother after the flush."

"I have a JD lawn tractor that I bought used, and I believe it never had maintenance. The oil was very dirty. On the third oil change, I used the flush, ran it for 10 minutes, and after draining and filling it with new oil, the oil is still clean. In my opinion, this stuff works!"

"I had some issues with my order, and when I wanted to return it, they refused. It was also sent to the wrong place. I wouldn’t recommend buying from them."

"I was neglecting my oil changes and noticed a drop in fuel economy. After using this product, my MPGs improved from 38 to between 46 and 51. It's definitely effective!"

"With my BMW, I've tried various engine cleaners but nothing worked until I used this one. It completely eliminated lifter knock and resolved the oil burning issue. This will be my go-to product from now on!"

"I bought a used car with lifter chatter. After using this product and changing the oil, the noise disappeared completely. I can confidently say this product fixed my issue!"

"I’ve been using BG 109 flush for years, and it does an awesome job at getting rid of built-up gunk and sludge."

"I couldn't see the results directly after using this product, but after removing the oil pan, I’m confident that it works well."

"The main reasons I bought this product are its affordable price and being made in Germany. I’ll update my review once I see the performance compared to BG 109."

"I found this product to be outstanding. After flushing my motor and changing the oil pan gasket, I was amazed at how clean the interior of the oil pan was after using Gunk Motor Flush."

"This stuff really works! I changed the oil and filter, then did another change after a few hundred miles on my recently purchased used car. Impressed with the results!"

"I've been using motor flush for years and I can definitely notice the difference in the oil. It stays cleaner longer because it starts out clean in the engine."

"I recently used the Lubegard Bio/Tech Engine Protectant and Engine Flush, and I am very pleased with the results. This product performed exactly as advertised, effectively cleaning accumulated varnish and deposits from my engine. The engine flush was easy to use and made a noticeable difference in my vehicle's performance. I also noticed an improvement in fuel economy and a reduction in sludge. I highly recommend Lubegard for anyone wanting to maintain their engine's health."

"I used this in my 2007 Silverado with a 5.3 engine that had an issue with oil pressure dropping after a lifter failed. After following the flush directions, the oil came out black as coal, but after the flush, oil pressure stabilized at 30. I added the protectant with fresh oil after replacing the bad lifter, and now pressure is stable at 60. The engine is running great!"

"I bought a very abused MB S550 at auction with a clogged variable timing actuator. After an oil change, flush, and protectant pack, I saw no change for a month. Then suddenly, the engine light went off! The oil passages for the actuator opened up, and I was able to avoid a complicated repair. I just ordered another pack!"

"I found that the oil pressure sensor can get clogged in my GMC pickup, but this product did a great job of cleaning those deposits."

"After draining the oil on my Kia with 165,000 miles, I added this product, ran the car for 5 minutes, and noticed a smoother operation. It really helped to get the gunk out."

"With my vehicle having 173K miles and regular oil changes, I didn’t see much change after using Berryman's. However, I’m concerned about people who don’t maintain their cars properly, as my friend, a Toyota mechanic, has seen many failed engines due to infrequent oil changes."

"It works just fine on my 5hp Tohatsu propane motor, but I only received one instead of the two I expected."

"I have both Honda and Mercury outboard motors. The Honda version fits my Mercury 4 hp 1993 motor perfectly, so I ended up returning this one as I didn't need to modify anything."

"For my 6 hp Mercury, I attached a little hose to it permanently, allowing me to flush the motor without needing a big bucket of water. I highly recommend this solution!"

"I had a P0430 code, so I decided to use this cleaner along with replacing the downstream O2 sensor. I've only driven a few miles since, but so far, everything appears to be working well."

"I followed the instructions precisely, but the check engine light remains on. I even changed both O2 sensors, but the light comes back even faster after using the cleaner. It seems this product didn't address the issue, as the mesh looks intact and just needs a good cleaning."

"I found this product to be very helpful! It was easy to use and had quick delivery. I believe it’s definitely worth the money."