Quote:
Originally Posted by silverbmwz3
Chris,
I'm confused - your first sentence seems to be suggesting you don't need to break it in quite so much?
Thanks
Paul
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No, just stating that to even try a "Hard break-in" is difficult even if you wanted to. You'd have to drive like a certifiable hooligan to do that in the 335D.
If you think about it totally logically - do a basically standard by-the-book break-in. Let things warm up, and bed in and as the miles grow gently use it more and more, with increasing loads.
You WILL feel it smooth out. What is the worst that can happen ? You'll get a nice smooth engine.
Look at what it says on the side of performance (or normal) brake pads ... you MUST break them in. Same for tyres.
Engine tolerances nowadays are much better than before, and the oil is miles better ..... but show me ONE person who doesn't say their car starts to feel smoother and better with more miles ? Why ?? If they are already Run-in?
Because things bed in, loosen up. Tightness smooths out. The engine runs in.
I've rebuilt engines and the bearing settings are such that they are slightly too tight on specs and are hard to crank over (which is way better than too loose/large - ever felt a big-end going, or piston slap, low oil pressure ?). A well used engine will crank over much more easily. The MOST IMPORTANT time in a rebuild is the few seconds after starting a new engine for the first time - some requirements like camshafts require a certain RPM to be held for a set time, build up of oil pressure, water temperature etc. BMW have already done that phase of checking the basics - now it is to you to finish the "running-in"
And if you want more power later (like it seems you do with the chipping questions), then chip it. Better on a smooth run-in engine than a bucket of bolts thrashed from day one.
Drive it like you stole it off the forecourt .... you are unnessecarily putting stress on all your components (engine, gearbox, bearings, brakes, tyres). You are trying to force the run-in process (as recommended by engineers who rebuild bike engines, or lawnmower engines ????????). It seems to mesmerise those who will also believe the "Get rich doing nothing" e-mails, or super bargians on E-Bay which turn out to be frauds, the too good to be true things. Why ... human nature - there are always people wanting everything for nothing. They prey on people's greed. In the pursuit of what - a few "alleged" extra BHP ?
It is ulimately your choice. Just seems logical to do it smoothly. What do you lose ? - takes about 1k miles driving reasonably.
I'd love to see a back to back dyno test with a well run-in engine versus a "Drove it like you stole it" engine - but both after 50k miles.
I used to work servicing cars (long time ago now) and you could most certainly tell good ones from bad ones ... and it did correlate directly to the style of the driver.
D.