Does Liqui Moly Engine Flush work? | Full Test & Review | Pro-line 2037

I measure the results on cleaning, deposits, compression and noise before and after running the cleaning cycle of Liqui Moly’s Pro-line Engine Flush on my gasoline, 2.0 litre turbocharged Audi A4.

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Chapters
0:00 Product and test category intro
4:51 Baseline tests
13:36 Installing new parts
15:28 Cycling the engine cleaner
15:57 Second set of performance tests
17:44 The results

I start with baseline figures of the car’s decibel readings at idle from an exterior and interior location, then take a sample of the current oil and filter it to look for deposits that might be floating around the oil pan. I take a good look under the valve cover for cleanliness in the head, then take dry and wet compression readings from all cylinders as well as inspecting the cylinder condition with a borescope.

Then I clean, and do it all over again! I try to be as critical and objective of the marketed benefits of Engine Flush as possible to avoid the hype of cleaning effectiveness based on disposed oil samples alone.

It’s entirely possible that Liqui Moly’s Pro-line Engine Flush DID clear out tight passages that assisted cylinder #4 into operating at peak current performance.

[Newmoneymarc]

You were supposed to flush the system of the original oil before adding the engine flush. Also they recommend you drive the car for 1-2 hours before draining

[Kedut]

Man videos like this is what youtube should be about, instead of clickbait ramble videos. It's really refreshing to see videos like this. Great job dude !

[rfarevalo]

The Oil Filter will trap deposits removed by Liquid Moly engine Flush. The filter paper before and after simple shows you have a working oil filter. Any particles you see in the filter paper are just deposits that haven't been filtered out yet in the cycle.

[Ininvesting]

One thing you want to crank the engine until the compression stops building, if you limit it to 5 cranks only you set your self up for failure especially when comparing to another reading. This is because the piston can be a a different part of it's stroke, theres 4 phases to a complete rotation, and if you start the test a a different part of the phase and stop a 5 you can get a higher lower reading if that piston is on its power stroke or sat exhaust stroke.

[skd]

Forget the product. Man you are the true you no words to hats perfection off the desk.

[RuperScooper]

Excellent production values - narrative and speed. Straight to the point no click bait waffle and YouTube tutorials at there best here - well done - if only they were all like this 😮 👍👍

[AudiTTQuattro]

I tried Liqui Moly engine lubricant/restorer in my 1992 Miata with 240k miles, for obvious reasons (stock engine, original miles). I of coarse, was skeptical, but what the heck. I only used half the can on the first go round. It took a while, but the compression and noticeable oil burn improved immensely. After about 2 or 3k miles, the compression and power were noticeable improved. I was surprised and amazed that it was actually noticeable. The engine has always been well maintained, but obviously it did benefit from treatment. It also improved valve tic on start-up, which has always been a problem on early Miata's. Still good at 252k miles.

[eeyvrcs]

@8:15 OMG. This is the first video/article that I've seen someone state or show the expected cylinder compression pressures for each engine size. I tested my 2008 1.8TFSI engine 6 months ago and got 124psi across all 4 cylinders. I was encouraged by the consistent readings but quite a bit worried they were actually all low and indicative of a problem. Whilst slightly on the low side it's a real comfort knowing they are all still well above the wear limit of 109psi. Thank you for your video.

[xtian_stw]

This is the most thorough review for this type of product I've ever seen. Fantastic work! I just came across this video in my searching of the liqui moly proline flush, was just watching each video as it came up. Started watching this and thought how odd i hadn't heard of this channel, it must be pretty well established to be doing a video of this quality...quick glance down...537 subs?? wtf? I was expecting like 500k?! Liked and subscribed immediately! Really well done on the video structure, audio and video quality too, I'll be sharing it with my car friends.

Came here to watch the review of the engine flush before I use it in my S2000, stayed and watched the whole video because of the quality content!

[azizhamed]

In the first reading, all cylinders are low, and the reason is that the engine did not reach operating temperature after that, in the second reading, after the engine reached operating temperature, it seems that all cylinders are equal in pressure. Thank you for this video, wishing you success always

[Ayten]

It lowered the compression on the three cylinders slightly because it broke down some of the gelatinized oil-carbon buildup which, to a point, actually seals the compression chamber more. This is before it gets too bad and starts to become very acidic and etch away at the linings, lowering compression.

[thivesennayager]

Thank you for taking the time to make such a detailed experiment

[tssci]

Enjoyed the video, clear and understandable, good attempt at the scientific method. The carbon on the cylinder walls is just a reflection. they are actually honed to mirror reflection and your seeing the edge of the piston. The varnish will never come off unless you use an industrial solvent and apply pressure or physical contact, such as you might see in a machine shop. Next time, flush the engine with brand new oil, take a sample, then add the Engine Flush. Then take another sample. That is the proper way to do it. Companies that test engine and oil, typically flush engines 3-4 times between runs to remove any residual oil or cross contamination. These modern, DOHC, VVT engines can retain 10-20% of old oil, thus the reason to flush the engine with new oil by changing, running for 15 minutes to complete mix the oils and drain again. This will net you a 99% fresh sump. Then if you see any significant deposits, it is likely the flush or the new oil actually doing its job in cleaning the engine. Another way to evaluate oil cleanliness and see carbon and insoluables in the oil is using radial chromatography. Place two drops of used oil on the center of a blank business card. Let sit and disperse for 6-8 hours. then examine under a back light and you will see any contaminates, carbon, soot, sludge if any. Very easy and cheap. The other option is to have a lab test the oil using optical or pore type partical test methods. The machine, transportation, marine, auto and military use this to evaluate filter performance and oil cleanliness.

[anthonyschenck]

The lower compression is because the carbon in the good cylinders, 1, 2 and 3, actually have formed to the internals, so when removing, expose minute new compression leakage areas. On your number 4 cylinder, you had carbon holding open your exhaust valves from the heat being greater in the back of the cam. Because of that, less engravnedd carbon on your sidewalls but now your exhaust valves seat all the way because the carbon deposits are no longer holding it open. I've learned this because this is a common problem on first and second Gen coyote engines.

[boots]

Fantastic video, almost to the level of Project Farm. However couple of big errors IMO, as others have mentioned.
1. Just crank until compression stops rising, might be 5, 6, 7...
2. You have a filter in the loop, so obviously where would we expect the majority of any gunk to have been deposited?
Aside those peanut gallery snarks, very good and useful to see that it didn't appear to do much cleaning of carbon at all.
Subbed.

[bqx]

Well, with my moms car (1.4 16V Seat Arosa Sport) a couple years ago, it was burning oil at about 1L/1000km, but after flushing with forte motor flush (warm engine, 45 minutes idling with sometimes revving up, to 1500rpm) it went down to 1L per 6500km. So that was a huge win too! (So it's nice to see you have improvements in the compression test)

[Corbots]

Awesome results. The flush freed up the rings on cylinder 4. Usually, you need to soak the rings over night with solevant. Plus the engine flush. To get those kind or results on an Audi

[tylerroe]

These types of additives (I prefer BG products) really shine after 3-4-5 full engine oil changes. We’ve been putting full synthetic 5w30 and the BG “MOA” oil additive in a 2000 Camry V6 for about 6 oil changes now. The old 5k-mile oil literally comes out looking brand new at this point. The first 2-3 oil changes were DARK, the oil filter was changed out twice as often as the oil was to catch anything that was dislodged. Additive from reputable brands definitely work. (BG, LiquMoly) But you have to repeatedly use them with every oil change to actually see results. When we did the valve cover gaskets on that same Camry V6 the inside of the cylinder heads were bright and clean. No coking or any deposits. One oil change and running for 10 minutes isn’t going to do anything except clean your cylinder walls a bit. Which is exactly what you experienced. Use BG’s MOA products and you’ll see crazy results long term.

[camai]

As a former Audi tech for years, those spark plugs are normal for that engine. Nothing out of the ordinary for this engine.

[sergiykud]

You seem like a guy who takes care of his car. The engine tarnish is nothing of the ordinary. It has no sludge, so i doubt the flush would do much for that. In my car, royal purple just changed the tarnish color to zinc yellow. The plugs clearly had issues. Thorough video man!