BriCK

Does sitting in neutral and putting the engine through it's RPM paces accomplish anything, instead of gradually increasing peak RPM everytime you drive it after the first 100 miles? I assume that this does nothing as far as getting a good piston ring seal and can't replace low RPM full-throttle acceleration.

Also, what's the theory behind varying the RPMs as you drive (i.e. alternating between 5th and 4th)? Don't all the parts move through the same range of travel regardless of RPMs, just at different rates of reciprocation?

Finally, what's a good cool-down time between the short 10-15 minute trips during the first 100 miles? Would 5 minutes do it, or do you really need to park the car for longer than that?

Thanks! If you think my eagerness to get broken in is going to cause me to hurt my car, please warn me!

QuattroRocket

Just be gentle for the first 1000kms or 600 miles to allow the engine to break in and all the parts to seat properly. I stay at or below 3000 rpm most of the time and stay light on the throttle. After 1000kms I will start pushing higher rpms and speeds gradually. There is no "rule" for break-ins.

jwillits

He said that anything less than track speeds and wear was OK. Was he just giving me the pitch?? I would really appreciate some more input to this user's post. I too want to know.

der Delfin '02

The normal advice I hear on break-in periods is that one should vary speeds (while in gear) regularly.

This means no long trans-continental road trips driving 65-85 mph for hours at a time.

Normal city driving would be a good break-in because this type of driving is the harshest on the engine. Once a car picks up enough momentum on the freeway/highway/interstate, it doesn't take that much effort to keep it going... Especially on a nice flat road while keeping it in 5th (or 6th for you 3.0 folks)

City driving, with all the braking, shifting, acceleration... etc... is a better way to put a car through its paces.

I agree w/ keeping the revs low (don't go try hitting the rev limiter, nor speed limiter) until at least the 600 mile safety interval.

Also, drive mellow for the last couple minutes before you park your car... that will help the turbo (if 1.8T) cool down.

Neutral will not put any real "load" on the engine. As it will be cranking against no real resistance... Imagine pedaling a bike with the rear wheel in the air... not very challenging...

Put the car through normal driving, avoid racing, or mad dashes to out run cops... you know... the usual... at least until after the break-in.

Bob Petruska

this is needed to seat the piston rings properly to minimize oil consumption.

Why.....

The cylinder bore walls are honed to a micofinished cross hatch pattern that acts like a file on the ring edges for a short period of time(few K miles).

Theory....cylinders are never bored perfectly round. Thus the piston ring faces when new will never press perfectly against the cylinder wall (micro gaps). This is why new engines consume oil at a higher rate than normal until broken in. By varying the speed and load on the engine, the ring faces are forced into the cross hatching that acts as a file to conform the ring faces to the slightly out of round clyinders to seat them as perfectly as possible eliminating/reducing oil consumption. The cross hatching eventually wears away in a few thousand miles with the pressure casused by varying the rpms. When you drive on say a very long trip without varying the rpm the cross hatching is slowly wearing away with the lightly touching ring faces but not micro machining the the ring faces to conform to the cylinder wall irregularities. Engine building has come a long way and the cylinder walls are more round than ever. That's why manufacturers can use synthetic oil in a new engine as years ago you needed standard oil (light weight) to accelerate the micromachining process. People years ago changed too early to synthetic wore away the cylinder cross hatching without machining the ring faces due to the enhanced lubrication properties of the synthetic oil and never really seated the rings. Once the cross hatching is gone due to this high synthetic lubrication the rings will never seat properly and you will consume oil abnormally!


I hope this helps why you should definitely vary the rpms!

der Delfin '02

wow... very nice answer... that validates the advice I was told =)

Bob Petruska

From my old engine 101 rebuilding days...now Chrome rings never seat, another story someday!

Ralphie

1000 miles (1600 kms)...

But the advice given above sounds logical and is backed up by very good reasoning, so I'm very inclined to believe it. These guys know what they're talkin about.

BriCK

Thanks, everybody! This helps!

daltex

The dealer only told me to keep it below 4000 rpm for the first 1000 miles. Also he said I need to check the oil frequently b/c in the 1.8 the turbo burns oil during the break in period.