Liqui-Moly Engine Flush

Never understood flushes. What's being flushed out? All the gunk? How did it get there, and where's it going when it was loosened up? The gunk can only be on the engine surfaces, in the oil, or in the filter. How do we know it worked? And what happens if any ports or channels are blocked by the loosened gunk? A well maintained vehicle shouldn't need a flush, even after 200k miles. Modern oils are so fricken awesome that if the oil is changed every 5 - 7k miles and a good filter is used, you can take the valve cover off at 150k miles and the cams will look like they just rolled off the assembly line. And they're making oil better. Don't know how, but it's interesting.
Your entire point rests on the idealistic assumption that everyone changes their oil "every 5-7k miles". Maybe this guy did that and if so then he should take your point to heart. But not everyone does that. And, um, used cars. And the "gunk" theoretically ends up in the filter, which gets changed. I would be curious to know about how long loosened "gunk" circulates before it's caught by the filter. Maybe long enough to plug a galley? :rolleyes:
 
Your entire point rests on the idealistic assumption that everyone changes their oil "every 5-7k miles". Maybe this guy did that and if so then he should take your point to heart. But not everyone does that. And, um, used cars. And the "gunk" theoretically ends up in the filter, which gets changed. I would be curious to know about how long loosened "gunk" circulates before it's caught by the filter. Maybe long enough to plug a galley? :rolleyes:
And, um, if a used car needs a flush, it's not worth buying. If you, um, want to buy a used car that needs a flush, go right, um, ahead.
 
Some interesting information that looks quite technical showing improvements (measured, not subjective) in timing chain issues from using flush products (post #11) as well as shortened oil intervals in Europe on some lower TBN/longlife oils in some older VAG engines. Anyway, found it farting around over on vwvortex and thought it was interesting and relevant.

Why the 3.2 platform chains stretch... or do they? The truth is out there! | Club GTI
 
So, I perceive the value of flushes, I don't buy new vehicles. Most vehicles I buy start at 100k miles. Don't know the history so I do a few short OCI's before doing a flush.

Here is my OCD, since (with my limited knowledge) I assume the oil I'm about to drain is spent. I change the oil with fresh cheap oil and filter, THEN add the flush solvent (LiquiMoly, or your favorite brand) following directions on container, then see how the oil comes out after 10 minutes. If dark, I continue short OCI's, then on the third one repeat this flush procedure. Historically, the 2nd flush is pretty clean. Then start my recommended OCI's without using flushes moving forward.

My goofy theory tells me that using clean oil, fresh filter and the flush, there may be better film strength and detergents to hold in suspension anything it may flushed.

My $.02
~C
 
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Concerning used car purchases, never assume OE maintenance is good enough. Never assume that an owner performed all OE maintenance.

I don't care for flush products but have used them too often. Too many used cars are dirty from negligent owners, and pathetic dealer or iffylube bulk oil, foolish owners skipping intervals(or always late), and then the clowns that are quarts low on oil all the time.

I prefer to recommend a good synthetic oil with shorter oil changes hoping to clean an engine up, while inspecting the filters after each interval to see if there is any crud collection. Alternate among the oil brands.

The pictures below are from an engine with mild sludge(never missed an OCI and textbook maintenance bulk oil and OE filters from dealer). By the 4th dealer service, around 22k miles, engine was had noticeable sludge.

More frequent fresh oil changes cleaned the engine with 'slow cleaning' products. This change either had a pint of Rislone, STP synthetic, BG MOA, Autorx, MMO, or Lubegard Biotech. Every oil change included a ~pint size additive that so many love to hate here. At each OCI, filter contents were less and less. When the filters started to come out clean, I then gave it a normal 5 minute cold engine no load solvent flush and all has been well.

At 22k miles, this engine was consuming oil. At 60k miles, not only is sludge non-existent, the oil consumption has stopped.

I believe this was the 3rd or 4th filter after taking over the maintenance of this engine. Filter now show nothing and is at 80k miles.
 

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Posted this somewhere else one time here re engine flushes, probably should post it here as well.

BITOGers be like...

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Just ran 2 cans of this through Mongo for my first DIY change. Good lord 9 qts is a lot of oil. I drained about a few qts (b/c I struggled) to grab a sample before the flush.
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Used two cans on a MB 276 engine that was 6k overdue for an oil change. The product has a solvent smell but it isn’t as strong as BG EPR. Not sure if it did anything, to be honest.
 
How does this prove it did anything at all? I have tried this product and found it did little to nothing on engines that really needed to be cleaned because of sticking lifters and rings due to poor maintenance.
I much prefer the cleaning action of Mobil 1 0w40 to these products, the proof it really cleans not just keeps the engine clean is undeniable.

Show some pictures of the bottom of pistons being cleaned with this product, let see how good it is. This is Mobil 1 0w40 after about a year, the piston at the top is covered by the pickup tube but still getting cleaned the one on the bottom and the others are almost free of varnish and deposits, the oil droplets are showing a red tint, that is the varnish, the top end was totally cleaned. The top piston is an indicator of the varnish and junk on the others and this area just gets splash oil.


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*Would the same cleaning not be possible with other M1 synthetic oil grades besides the 0W40 ?
 
If you're going to use an engine flush, the Liqui-Moly product to use is their Pro-Line Engine Flush which comes in 500 ml cans (good for up to 5 liters). This is their most concentrated formula. Although the recommended duration is 10 minutes, you can run it up to 20 minutes at idle with no ill effects provided you do NOT raise idle speed.

I've been using it for 9 years with no ill effects, but do not expect a day and night difference simply running it for 20 minutes straight the first time. If the engine is sludged, Liqui-Moly have recommended their Öl-Schlamm-Spülung for 300 km (188 miles) prior to an oil change. If you use the translate feature on your browser, this is an interesting and short blog post from Liqui-Moly.

From experience, I would highly suggest replacing the oil filter at the very least, as it does get pretty nasty and turns the oil dark red. Maybe even change the oil with cheap mineral oil, put a decent filter on and run this stuff before changing the oil.
where does one buy this stuff in the USA? not that I want to, just curious. never seen it.
 
where does one buy this stuff in the USA? not that I want to, just curious. never seen it.
I get it from FCP Euro, any LM dealer online or in-store will have it. Amazon has it. I bet some regular auto parts stores carry it. If you want to use it...that's fine too...hahahahaha
 
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