[Mosaud1998]

First off I want to say, No I am not going to use any sort of engine flush. I was just curious, so I looked up "best engine flushes" on google and what not and got mixed reviews. Some people were saying engine flush is like magic and does no harm to your engine. Some folks were saying it can harm your engine seals which will cause your engine to leak. So, I went ahead and emailed LM (liqui-molly came up has one of the highest-rated engine flushes) application engineer about their pro-line series engine flush and asked him where the deposit from the flush goes? Does it all drain out of the engine or does some stay in the engine? He emailed back and said with LM engine flush the deposit drain out from the old motor oil. But in theory, motor oil doesn't drain out of an engine 100%. There's still about 1% of oil left in the engine. I personally wouldn't use any sort of engine flush in my car. Oil changes have been done every 5-7k miles or 6-8 months (whichever came first) by me and the previous owner using either BMW OEM oil. So, internally my engine should be clean. Let me know what you guys think.

[bluewater328]

I'm torn on this one as the "BMW Doctor" said not to use any...so with that, I'm inclined to think that we should. :P

[Mosaud1998]

Originally Posted by bluewater328

I'm torn on this one as the "BMW Doctor" said not to use any...so with that, I'm inclined to think that we should. :P

Why though I'm afraid to use it. I don't really want to harm a $5k-$6k engine using an $8 product. Plus, if you change your oil every 5-7k mile, I don't think you should have any "deposits".

[bluewater328]

Originally Posted by Mosaud1998

Why though I'm afraid to use it. I don't really want to harm a $5k-$6k engine using an $8 product. Plus, if you change your oil every 5-7k mile, I don't think you should have any "deposits".

There's a bit of sarcasm in there...mainly because I can't stand the "doctor" (not speaking of Mr. Who). I think its fine to use additives every couple of years. Things that clear your injectors, fuel system, etc have their place as not every gas is as good as it says it is, plus neither is our engine. The thing you want to consider most is how something will affect your seals/gaskets. That's the largest worry. If you're beyond that, then everything but Boostane is fine :P

In moderation, say every 3 years or so, I think its fine as a maintenance item and can only do good. You're supposed to flush them all anyway immediately after use (which includes idling the engine). So most of it is detergent or alcohol (burn your problems) anyway, so the effect is somewhat minimal. If your car is used or giving you some odd idling, its not a bad idea if you haven't done it before.

But as you say, an engine that has mostly highway miles and regular oil changes twice a year or whatever your oil analysis says, is probably fine without it. As an N52, you probably have less issues and a good fuel system cleaner is about all you really need. A few people have stuck boroscopes down there and these engine cleaners do take away some of the carbon deposits. So it's up to you. If it ain't broken or bogging, don't fix it.

[Mosaud1998]

Originally Posted by bluewater328

There's a bit of sarcasm in there...mainly because I can't stand the "doctor" (not speaking of Mr. Who). I think its fine to use additives every couple of years. Things that clear your injectors, fuel system, etc have their place as not every gas is as good as it says it is, plus neither is our engine. The thing you want to consider most is how something will affect your seals/gaskets. That's the largest worry. If you're beyond that, then everything but Boostane is fine :P

In moderation, say every 3 years or so, I think its fine as a maintenance item and can only do good. You're supposed to flush them all anyway immediately after use (which includes idling the engine). So most of it is detergent or alcohol (burn your problems) anyway, so the effect is somewhat minimal. If your car is used or giving you some odd idling, its not a bad idea if you haven't done it before.

But as you say, an engine that has mostly highway miles and regular oil changes twice a year or whatever your oil analysis says, is probably fine without it. As an N52, you probably have less issues and a good fuel system cleaner is about all you really need. A few people have stuck boroscopes down there and these engine cleaners do take away some of the carbon deposits. So it's up to you. If it ain't broken or bogging, don't fix it.

No idle issues or such for my car. Sitting at 72k miles. I might go ahead a do an LM flush on my 5th oil change after I get a UOA. Or just use a bottle of Techron

[CTinline-six]

1. BMW Doctor is a quack. A lot of his "advice" goes against factory service info, and some of it doesn't even make any sense.

2. A flush wouldn't harm a clean engine, but then again if it's clean you don't need it. In a severely sludged engine, a flush is harmful because it can loosen too much sludge at once and clog oil passages, the oil pump pickup, etc. For a dirty engine the best thing you can do is just use good synthetic oil and a good filter and change it regularly. This will clean the engine gradually as you drive.

[rjahl]

I don't plan to introduce anything to my lubrication system that might have a negative affect on the various seals, gaskets or bearings found in these motors. Don't care what the label says.

Good oil change intervals with the correct oil is the best recommendation anyone can give. Follow the guidelines and you won't need to flush the motor.

[hassmaschine]

Originally Posted by bluewater328

I'm torn on this one as the "BMW Doctor" said not to use any...so with that, I'm inclined to think that we should. :P

Is that one of those self promoting, idiotic YouTube shills? lol I get your sentiment though.

But personally, I've done the seafoam thing, and various other engine snake oils in the past. Save the $10 and buy yourself a take-out lunch instead.

[CDirks]

While I haven't used anything I classified as a "flush", I have used the LiquiMoly Ceratec before. Maybe snake oil, but I figure at 200k+ it can't hurt to have some extra wear protection.

Regarding flushes though, if you're performing your maintenances consistently then there shouldn't be a need for flushes, right? Just ask EfThreeOh...

[4foothill]

I have used liquimoly's engine flush treatment at 100k miles, mostly because it came free with my oil. Hard to say if it cleaned up much since there wasn't much visible gunk in the first place. When I took my valve cover off it was very clean in there so maybe that helped.

But like everyone else has said, fresh engine oil is one hell of cleaner. In fact I occasionally use leftover oil to clean all sorts of metal things - it works wonders on rust!

[Mosaud1998]

Originally Posted by CDirks

While I haven't used anything I classified as a "flush", I have used the LiquiMoly Ceratec before. Maybe snake oil, but I figure at 200k+ it can't hurt to have some extra wear protection.

Regarding flushes though, if you're performing your maintenances consistently then there shouldn't be a need for flushes, right? Just ask EffThreeOh...

I used Ceratec at 68k miles. I am at 72k right now. Haven't noticed a huge difference in anything lol. Idk if I should continue to use it or is it a waste of money.

[CDirks]

Originally Posted by Mosaud1998

I used Ceratec at 68k miles. I am at 72k right now. Haven't noticed a huge difference in anything lol. Idk if I should continue to use it or is it a waste of money.

That's the tough part- you're not going to notice anything unless you perform an oil test and compare it to a vehicle of similar mileage/history. The goal for me is to keep things running smoothly until I decide to get a new car. Maybe only starting to use it at 200k is closing the barn door after the horses have left, maybe not.

If you plan on keeping your car for the foreseeable future, I don't believe it to be a waste of money at all

[E92William]

Originally Posted by bluewater328

I'm torn on this one as the "BMW Doctor" said not to use any...so with that, I'm inclined to think that we should. :P

For a second I thought this was someone taking "the doctor" as a factual source

[Mosaud1998]

Originally Posted by CDirks

That's the tough part- you're not going to notice anything unless you perform an oil test and compare it to a vehicle of similar mileage/history. The goal for me is to keep things running smoothly until I decide to get a new car. Maybe only starting to use it at 200k is closing the barn door after the horses have left, maybe not.

If you plan on keeping your car for the foreseeable future, I don't believe it to be a waste of money at all

My plan is to keep the car until something major doesn't bust that cost more than the car. I'll probably use it on my 5th oil change. I buy stuff through fcpeuro. But, I am not sure if Ceratec is covered under the lifetime warranty.

[E92William]

Engine flushes are the same imo when it comes to arguments as transmission fluid changes on high mileage cars. I've never had them do anything bad but there's always that one guy who knew some guy who knew his cousins friend who had an issue supposedly because if it...

Chances are nothing is gonna go wrong with it, it's meant to be run on the engine at idle for barely 5 minutes and it's a high detergent additive that dissolves carbon and sludge build up into a liquid so it can be drained out on the oil change after you're done running it. If an engine flush supposedly ruins one of your seals it's because that seal was barely sealing with a piece of sludge. Engines aren't meant to have carbon and sludge inside, unless your engine is holding on by a thread it can't do any harm

[Efthreeoh]

Snake oil.

400,000 miles. OCI still above 14,000 miles. BMW oil and MANN filter. Been in the top and bottom of my engine over the years. Posted pictures. Never a spec of sludge.

[Mosaud1998]

Originally Posted by Efthreeoh

Snake oil.

400,000 miles. OCI still above 14,000 miles. BMW oil and MANN filter. Been in the top and bottom of my engine over the years. Posted pictures. Never a spec of sludge.

Yeah, I've heard a few ppl say that Ceratec is just snake oil in a bottle

[E92William]

I guess it's good if you buy an engine that already has sludge in it contrary to doing it for no reason on a clean engine

[Efthreeoh]

Originally Posted by E92William

I guess it's good if you buy an engine that already has sludge in it contrary to doing it for no reason on a clean engine

And I'd add, if you buy a car that has engine sludge, then the car has not been properly maintained and cared for. Sludge forms from not properly heating the engine (very short trips) or very long oil change intervals where the oil looses its additive package, and way beyond any manufacturer's OCI recommendations.

[Efthreeoh]

Originally Posted by Mosaud1998

Yeah, I've heard a few ppl say that Ceratec is just snake oil in a bottle

That's how it is usually sold... by the bottle.

[JonOhh]

I've always been very wary of engine flushes, especially those which state they should only be used for 10 minutes maximum with an idling engine. (Like Motor Medic).

That seems to indicate that the product reduces the film strength of the oil so significantly that loading the engine at all could cause significant bearing damage (it doesn't take much).

Personally, the risk there is too great for whatever gain. Even if you follow the instructions, you're operating the engine at a much greater risk of significant damage you may not notice until many, many miles down the road.

Over time, and with correct operating temperatures always reached, a good oil will be able to reduce the amount of sludge on it's own, though you may want to change it more often since additive/detergent packages deplete.

Back in high school, I used Motor Medic Motor Flush on my Abarth to try to see if it'd have any effect on an issue I thought was with multiair, and when I drained the oil it was alarmingly thin- not surprising considering the viscosity of the flush which makes up 1/4 of the engines oil capacity itself (though I kept it at 1/8). Go shake a bottle of motor flush and I think your decision about using it will be made.

[E92William]

I remember when I worked at Autozone in highschool we had a guy come in complaining that his engine was making noise after someone sold him an oil "additive" in our store and well they had sold him engine flush and he had been driving the car around with it. No idea what was done about that lol but it sounded like it was ticking like mad. I don't think it's as big of a deal if you don't load the engine though. It was also a fiat a 500L