What's the real deal on break-in (running-in)?

[HonoluluDoug]

Just got a black/black MCS on Friday as a self-indulgent Xmas present to myself. With only 230 miles on it, the engine already feels a lot smoother and rev-ready. I've been following the manual's oppressive break-in routine (absolutely no full throttle acceleration, 1400 miles under 4.5K RPM, then gradual increase in RPM). Please! This is kinda like saying you have to take Viagra for 2 months before you can put it to its intended use!

I've heard a lot of theories about why the MINI's break-in period is so long: (1) Since they cover maintenance (oil changes, etc.), they load the engine up with synthetic oil -- which is good because it's "slippery", but is bad because it's so slippery that it impedes the usual bedding-in of mechanical components; (2) the long break-in period is completely arbitrary and created by "bean counters" who calculate that most of the warranty repairs would be caused by new owners abusing the machinery.

Anyway, I'm interested in hearing from anyone who actually knows why the break-in period is so long. I'm looking for a credible response telling me it's good for the engine to start redlining it from the third tank-full, but I'll pay attention to good counsel whatever it is.

Doug in Honolulu

[Jazzy Jase]

HonoluluDoug,

You could have a read of this thread. It puts forward an argument to drive the engine hard from new:

http://www.mini2.com/forum/showthrea...ght=running+in

[friedduck]

I don't know why I continue to defend my position, but do what Mini says by the book. There are a lot of half-baked opinions out there, and the opinion of the folks who built your engine. (Who, by the way, have a vested interest in seeing that your engine lasts.)

Your choice

Jeff

[Bilbo Baggins]

HonoluluDoug,
IMHO, the info/opinion expressed by MotoTune is from someone who is only concerned with the development of powerful race motors. Race motors are concidered expendable and re-built on a regular basis, sometimes after each race.

I would temper any decision you make about the breakin of YOUR engine with that thought in mind if you choose to deviate from the factory recommendations. That and the likelyhood that the ECU most likely has the ability to record the maximum RPM and the milage when it was reached, or maybe just the ability to record if the 4.5K was exceeded prior to 1400 mi. Just so the factory will know whether or not it must honor the warranty.

Be patient, 1400mi isn't so far away, even 2000mi if you include the 'easing' up to max rpm. From my own experience, it seems like it will take alot of will power to follow the recommendations but you will see that there is plenty of power and plenty of gears to play with. You also will learn that the places that you will have the most fun is not on the limited access hwy, but on twisty bits such as the Pali Hwy. or especially on less traveled roads with lots of curves and little traffic.

Relax, enjoy.

[joshr]

and i just rolled about 750 this morning. i'm following the suggested break in period/procedure. patience. i found that the engine loosens up quite a bit somewhere around 500 miles, and is definitely more fun now, even below 4.5krpm. the miles go on fast, and the more you put on, the more you'll want to put on, so i say keep to the book.

[MissouriMini]

I plan to keep to the book also when I get delivery in March However, I thought I'd drive the 800 miles from St. Louis to Denver about that time as part of my break-in period and as a means to get the miles over with quickly. However, I've heard in the past that break-in miles should NOT be Interstate highway miles (as in constaint high speed single RPM miles), but fluctuating city miles with varied RPMs. Is this true Thanks for the help

[friedduck]

True. The idea is that you're supposed to vary the RPMs and load on the engine to break-in correctly. I read a piece once by a bike tuner (can't recall who) that explained that ideally you want to alternate loading/unloading an engine. During the moments without load, the oil carries away contaminents. I, of course, can't explain it as eloquently, but you get the picture.

For race cars/bikes, break-in happens quickly. Intervals of part- and full-throttle operation followed by rest periods. They get max power, and of course, longevity is less of a concern.

One thing that I did when I reached the end of break-in, was a couple of part- and full-throttle acceleration runs, followed by coasting/idling. I did this immediately prior to changing the oil. While you may not choose this practice, if you *are* going to do that sort of thing, doing it right before an oil change makes sure that any byproduct is removed soon thereafter.

Jeff in ATL

[minimc]

Quote:

Originally posted by friedduck
I don't know why I continue to defend my position, but do what Mini says by the book. There are a lot of half-baked opinions out there, and the opinion of the folks who built your engine. (Who, by the way, have a vested interest in seeing that your engine lasts.)

Your choice

Jeff

half-baked here...

I don´t know why you continue to defend your position either?

If you folks had gone to the bother of researching things extensively you´d understand that MINI´s break in makes little sense from a durability standpoint. But NO... yer gonna follow BMW´s advice cuz you´re good little MINI owners who´ve been scared into following THE RULES.

This aint a rocket engine made out of never before used materials. Its a car engine. It breaks in the same way other 4 stroke engines made of similar materials do. Nothing MINI/BMW says can alter this.

If you want to beleive that your MINI is special, and that it takes a careful and deliberate break in period to get the most from your engine then so beit. Some folks need to believe the hype.

Or... you could consider that this is the SAME company that said that it couldn´t activate the fog lights of North American vehicals because it was against the law (complete & utter rubbish). Why should you believe MINI/BMW is being any more honest about break in?

There are numerous sources you can seek out if you want the anwers. ...Some even from BMW employees who will speak candidly.

Wait... what am I arguing my point for?

[SilverGAGT]

I am now officially on the list for my Mini....June build date. Assuming everything goes as planned, I'll take delivery in July, and fully plan on following the owner's manual for break-in. It really is worth doing everything in your power to keep the dealer on your good side. I have found this out with my current car and it has paid off.
I have no technical background on whether or not the car will perform better or worse based on how you break it in, but again, it helps to have the dealer on your side.

[BruceK]

I strongly disagree that BMW is guided by trying to save its corporate butt when it specifies a detailed engine break-in procedure to be followed. No matter how you treat the engine when it is new (rough or gentle, by the book or not), there will likely not be any problems at all during the short period the warranty is in force. So really, why would BMW care what happens to the engine when it is past the warranty period?

Here's a good argument for a moderate break-in regimen:

http://www.dezmo.com/breakin.html

Here's a quote: "... 1) If the break-in begins at high RPM and heavy throttle, the process may generate more heat and metal debris than the system can handle. Then the result is destruction of contact surfaces in some parts of the engine. (2) If the break-in begins at a lower energy level and builds up gradually to higher revs and throttle, the washing action of the oil will keep up with the generation of wear particles, and the surfaces will bed into each other in such a was that the oil film can carry the load. (3) The 3rd possibility is that break-in will fail-- usually as a result of such light-duty operation that parts are not loaded together forcefully enough to bed-in to one another. Rings glaze and fail to seal. The engine never delivers full power. Fortunately, this is rare where production machines are concerned...

AND:

Quote: "...If you push too hard, too soon, the parts will score and scuff each other because the heat generated will be enough to destroy the oil film locally. A scuffed piston ring doesnt seal...

[Antranik]

Minimc i am confused, isn't the break-in procedure in the mini manual similar to all other manufacturers cars procedures? Don't they all basically say, vary rpm's, dont go WOT and dont overrev in the first few tanks at least of your engine?

I am absolutely NOT attacking you, i am just unclear about where you stand on how a 4-stroke motor is supposed to be run-in. I have always thought it was the way the car manuals tell you to do it

[JaridP]

Hmmmm. Try this example..Running shoes...You buy a brand new pair of shoes for a marathon.. Most people would run around the block or what not to break the shoes in. That way, when it comes time to go for broke during the race you aren't stuck with blisters and sore feet. Yes the end result is the same but you do less theoretical damage in the process. BruceK is right. Not following the breakin can cause premature wear to piston rings, valve seats, and engine bearings. It is always a good idea to be a tad on the gentle side to a brand new car. I'm sure we all can have a little self control when we get into our beauties for the first couple long drives..I know I did....It was hard..But I did it. (I did change the oil at 2k even though its not needed.)

[HonoluluDoug]

BruceK,

But the article on break-in you mention also brings up the problem with synthetic oils during the process:

"Many engine builders agree that you should not try to break in an engine on synthetic oil. *If the oil film is too good, it will support even parts with extensive surface roughness. *Only a small amount of local bedding-in may occur on the piston rings, in a poor fit (glazing) that improves only very slowly over time."

And although I haven't done extensive research, it seems to me that the break-in period for the Mini Coopers are longer than most new cars. The dealer told my brother he could red line his new Mustang Cobra right out of the lot if he wanted to(!)

Anyway, I'll continue to break-in my MCS according to book until I find anything definitive persuading me otherwise. And I'll report that here in that event.

Doug

What exactly do they mean by vary the rpm? I mean, I know that you are supposed to vary the rpm, but how exactly? I am going to be driving my mini back from the dealer ship 2.5 hours on the freeway. Should I be going from 4 to 5 to 6 all the time? How frequently?

-Andrew

[BruceK]

Quote:

Originally posted by L8 Apex
What exactly do they mean by vary the rpm? I mean, I know that you are supposed to vary the rpm, but how exactly? I am going to be driving my mini back from the dealer ship 2.5 hours on the freeway. Should I be going from 4 to 5 to 6 all the time? How frequently?

That's exactly what I did when I got my MINI. I also drove many hours on a freeway after picking the car up and about every 5 minutes I shifted from 4th to 5th for five minutes, then to 6th for 5 minutes and back down again. Since the gearing is so tall on the Cooper S it's easy to follow that and still maintain freeway speeds.