OpenTube

I Tested Liqui Moly Engine Flush on a 220,000 Mile Honda… Here’s the Truth

Man Vs Cars

348,621 views

I tested Liqui Moly Pro-Line Engine Flush on my 220,000 mile 2004 Honda Accord to see if engine flush additives actually work on a high mileage engine.

After viewer requests flooded in following my diesel fuel and kerosene engine flush experiments, it was finally time to test one of the most recommended engine flush products on the market.

Before using the Liqui Moly engine flush, I performed:

Oil pressure testing
Compression testing
Internal engine inspection with a borescope camera
Valve cover removal and sludge inspection

Then after following the exact Liqui Moly procedure, I repeated every test again to see if there were any measurable changes in:

Compression
Oil pressure
Engine cleanliness
Engine noise
Sludge buildup

Did it actually work… or is engine flush just another automotive myth?

Vehicle:
2004 Honda Accord
3.0L V6 Engine
220,000 Miles

Here is the link for this handheld JumpPack:
GS300 Car Jump Starter,3000A Portable Battery Jumper Starter:
https://amzn.to/3PnMtVC

Website: https://www.lifmocer.com

#LiquiMoly #HondaAccord #EngineFlush #HighMileage #K24 #CarExperiment #AutomotiveTesting #ManVsCars

20 Comments

@miken8150 4 months ago

Try Valvoline Restore and Protect on a vehicle, supposed to be amazing although they say it can take 2-3 oil changes.

@1toneboy 4 months ago

Tldr ‘well, at least the engine didn’t look worse after using it’

@SanMan583 4 months ago

One thing I've heard about any flush product like this...

Once you drain the original oil, take some cheaper oil and fill the car up with it. Run the car for a little bit more, and then finally drain that oil and put in your good stuff (Its extra work and money yes, but you're also not always going to do a flush).

Recently did it on a friend's car who somehow was 10k miles past their service date, and just running some cheap oil through after the initial flush, the brand new oil came out just as dark as their old oil.

@xJoey2213x 4 months ago

You should replace the filter prior to doing these experiments

@chrischarles9218 4 months ago

That engine is very clean considering the miles. Its oil was changed regularly.

@mr.mr.3301 4 months ago

I’d be more inclined just to use Valvoline restore and protect

@mightyfinejonboy 3 months ago

i think the engine flush is meant for the high velocity areas like oil passages and oil squirters, etc.

@jonathanhelmbold1162 4 months ago

Engine sounds smoother and quieter than before. Always notice this after doing this on several vehicles I've serviced.

@steveeisenhauer3003 4 months ago

I've been using seafoam for 20 years. I swear by it and have never been disappointed.

@scottc4433 4 months ago

I believe Seafoam has been proven on YouTube to be the most effective for crank case and intake tract cleaning

@nevrcm3261 4 months ago

IMO, a good and fair test. I think this type of flush as a "1 and done" would fail across the board for almost all use cases (15 minutes of thinned oil + detergents detergent will NOT wipe away 240,000 miles of deposits and sludge).

However, using this as a part of a maintenance routine, say every other oil change, probably is where this would exhibit benefit over time to clean deposits relatively soon after they've...well deposited

@stefang1087 4 months ago

You will never know if the sludge was present in the old filter before the treatment or it came after the treatment. After the treatment it is recommended that the next 2-3 oil changes should be done sooner than usually.

@red86guy40 4 months ago (edited)

My personal experience with the Liqui- Moly engine flush, I was letting my 2005 Tacoma idle at work during the winter time just before going home from work. When I came outside about 10 minutes later, I heard engine knock and a puddle of oil on the ground, turns out my rear main seal popped. Anyway, long story short, a body shop technician recommended I try the Liqui-Moly flush (I did find very minimal amounts of glittery oil which could barely be noticed during the flush), and then add Liqui-Moly ceratec after the flush. Once completed, I could believe my ears, the knock is gone! Back in December, I thought my engine was going to blow, today, it is still running strong. Please note that this is MY personal experience, I am not advertising for Liqui-Moly, nor am I affiliated. I'm sure depending on circumstances, everyone else's results can vary.

@oneanddonediy 4 months ago

The 505 CRO should have been the test. It's the only one I have ever used that made any obvious difference, and I have tried a few, even this one used in this video.

@SantaClaw 4 months ago (edited)

You need to check the new engine oil after 500 or so miles. It doesn't dissolve the grime immediately, but it works on it over time so you don't fill oil ports or the strainer with junk. Usually, the inside of the engine won't look significantly better until the next oil change after.

@siamanspaps 4 months ago (edited)

In good old days of my veteran mechanic friend in his words - two back to back oil changes with a 1000km interval were considered engine cleaning - rest was waste of money and "asking for trouble"
Which pretty much we can summarize from this video series.

@willmill409 4 months ago

I cant really speak on the engline flush but liquimoly jectron and their fuel system cleaner pro line are amazing

@HUBBABUBBADOOPYDOOP 4 months ago

People think there are actual chunks flying around.
Most of what you are seeing is from vapor deposition, and sediment deposition because of infrequent trips.
To clean without disassembly you'd have to create a fog of cleaner. Hot, acidic and caustic to knock the staining out would be conventional ATF and a large remote filter, and allow the ATF to vaporize, risking gasket damage & component warpage. Examine a THC 400 valve body, rows of bolts, zero sludge, transmission gets same temp as engine, fluid temp even maintained by the engine's radiator. One thing cuts another. I've always relied on ATF.

@jefffanning2799 4 months ago

Liqui Moly flush has proven it´s value to me several times.

@tomster_6274 4 months ago

Quite a few people are suggesting Valvoline Restore and Protect, and I agree with this. I’ve ran it on my Audi that burnt over a quart every 5k miles and after 2 intervals of that it’s cut down on oil burning drastically. I’m also currently running it in my Saturn SL2 and I’ve already noticed improvement on that too.