New Car Break-in period

J

jluspo

New member
Hi!

I just took posession of a brand new 2007 Z4 3.0si coupe with the sport and premium package 8) Yes, it's 2007 and it's still brand-spankin-new - it has 110 miles when I took posession. I tried searching for how to break in a car but no results. So, you guys have any advice for a newbie Z4 owner on how to break-in his car? Some say to take it easy the first 1K miles. Some say to rev the engine high to "fit" the pistons to the ring. Other say BMW does not need a breakin. I'm planning to keep the car for a long time so I want to do this right.

Thanks in advance and thanks for a great site.
Joven

By the way, I'll post pictures this weekend.
 
I did a BMW driving course 2 years ago when we were using new E46 M3's. The one I drove started the day with 250 km. I spanked that car and then some. It had the S-54 engines break-in paster on the windshield. You know the one that tells you to not go over 5500 rpm and 170 kph while not pushing the pedal to the metal. Well guess what? We did all that! Red-lined the sucker. I asked the Chief Instructor about the break-in and he said that the engine was already broken in the recommendations did not need to be followed....

When I got my Z4M.... Well - that's all I have to say about that :D
 
I'm currently breaking in my Z4MC and I intend to follow the BMW recommendations, rev < 5500RPM and Max Speed 170kph. I was also told to avoid long distances on cruise control which would tend to keep the engine at the
same RPM for long periods of time. Whether that makes sense at all is unknown to me.

Cheers.
 
That makes sense and I plan to do the same with my new 08 3.0si that I am picking up tomorrow morning :D

The reason you don't want to set the cruise control is cause you want to vary the RPM's during the break in period so the cylinder does not form a "rim" in the casing. The rod actually flexes as the cylinder moves up and down in the casing and you want to vary the flex of the rod otherwise the cylinder will stop at the same point in the casing and as the newly formed metal heats and expands it will form a rim and then when you rev it to a higher RPM later on the rod will flex more and the cylinder will break that rim and you will have metal shavings in the casing. The reason you don't want to exceed 5500rmps is so you don't overflex the rod initially - it is a newly formed metal too and needs time to get used to it's new job. I can't think of any good metaphors at the moment, so I hope explained that so it makes sense.
 
enfield said:
I did a BMW driving course 2 years ago when we were using new E46 M3's. The one I drove started the day with 250 km. I spanked that car and then some. It had the S-54 engines break-in paster on the windshield. You know the one that tells you to not go over 5500 rpm and 170 kph while not pushing the pedal to the metal. Well guess what? We did all that! Red-lined the sucker. I asked the Chief Instructor about the break-in and he said that the engine was already broken in the recommendations did not need to be followed....

When I got my Z4M.... Well - that's all I have to say about that :D
Click to expand...

Seriously??
 
Watch the Ultimate Factory video and then answer the question for yourself. The engine has only barely been run at all with gas in it as of when it is delivered. The entire engine checkout process is done without combustion.

Lots of different schools of thought on what is "the Right Way(TM)" and it seems to boil down to whose opinion you decide sounds like the one you like.

The path I followed with this car was to avoid cruise control and vary speeds on the highway. I kept the RPMs below 4K for starter but did do at least a couple of run ups to around 6K RPMs during the first 200 miles when the engine was warmed up but always allowing the engine to cool off after doing that. Several mechanics claim that this helps to do a better job of seating the rings but it sounded like heat was an enemy on the sidelines if you overdid it. I kept that up for the first 1K miles and then gradually started to open it up more. The engine was definitely very tight at that stage compared to how freely it runs at high RPMs now and it really didn't loosen up until around 1.5K miles and kept getting smoother up to around 5K miles. I have 13K miles on the car now and the engine is smooth as silk right up to redline. At 3-4K RPMs the engine is almost silent on the streets until you punch it so it feels just right to me.

Is that the "perfect formula"? I don't have a clue. The only thing I can state for sure is that it doesn't seem like I hurt it with that treatment in terms of how it's running after 13K miles. Will this make it run better after 100K miles compared to the "drive it like you stole it crowd"? No clue - get a statistician to take a sample of all of us and then compile the numbers after we all reach 100K miles.

Back to square one - use whatever method makes you feel better about the car. My guess is that most of the drive it like you stole it proponents are leasing the car and don't care what happens to it after the lease expires.
 
Thanks all for the replys!

I guess the advice that makes the most sense is to vary the RPM but not over 5000RPM. I can see why setting the cruise for a long time can make make an imprint on that setting.

What about the rest of the car? Are there any breakin procedure for those? For example, transmission, suspension, etc. These items are new too! By the way, I have the 6 speed manual transmission.

Thanks again,
Joven
 
Breaking in the engine as described above by alanl and others will have the required break in effect on all the other components to a large extent. So if you gentle on the revs and top speed, vary speeds, etc. so you will be on the transmission, diffs, wheel bearings, etc.

Brakes need time to bed the pads in and treat the discs

To a lesses extent tyres need to cure and settle.

Although engines are made to such fine tolerences these days and strict break in periods are not mandated my personal belief in simple terms is the 'drive it like you stole it' is great for the person who wants to keep the car a year and hand it back, or the company car owner. Treat it gently for a few hundred miles using progressively more throttle, revs and braking and it will repay you over the years with less wear, component failure, replacements, etc.

Enjoy
 
z44me said:
Drive it like you stole it.
Click to expand...

What you guys say makes sense, but I didnt say that off the cuff. It comes straight from one of the best engine builders I have ever known. His thinking is, the parts(metals) are all better than they used to be, the tolerance is tighter and the lubrication is far superior to the "you gotta break it in days." He says drive it how you want, it will make no difference in the long term.

That gives you a couple schools of thought. It does seem the majority favors the break in period.
 
Ski said:
enfield said:
I did a BMW driving course 2 years ago when we were using new E46 M3's. The one I drove started the day with 250 km. I spanked that car and then some. It had the S-54 engines break-in paster on the windshield. You know the one that tells you to not go over 5500 rpm and 170 kph while not pushing the pedal to the metal. Well guess what? We did all that! Red-lined the sucker. I asked the Chief Instructor about the break-in and he said that the engine was already broken in the recommendations did not need to be followed....

When I got my Z4M.... Well - that's all I have to say about that :D
Click to expand...

Seriously??
Click to expand...

Yes, seriously.
 
I am wrong. It is on page 74 of the 08 owners manual a complete breakin procedure for the things you asked about. I dont have time to post it till tonight. Maybe someone else can get it on here for you.
 
flyboyaj said:
That makes sense and I plan to do the same with my new 08 3.0si that I am picking up tomorrow morning :D

The reason you don't want to set the cruise control is cause you want to vary the RPM's during the break in period so the cylinder does not form a "rim" in the casing. The rod actually flexes as the cylinder moves up and down in the casing and you want to vary the flex of the rod otherwise the cylinder will stop at the same point in the casing and as the newly formed metal heats and expands it will form a rim and then when you rev it to a higher RPM later on the rod will flex more and the cylinder will break that rim and you will have metal shavings in the casing. The reason you don't want to exceed 5500rmps is so you don't overflex the rod initially - it is a newly formed metal too and needs time to get used to it's new job. I can't think of any good metaphors at the moment, so I hope explained that so it makes sense.
Click to expand...

Thank you for the explanation.
 
Ok, here it is straight from the owners manual.

Engine and differential:
Up to 1200 miles. Drive at varying engine and road speeds, but do not exceed 4,500 rpm or 100 mph. Refrain from using full throttle and avoid pressing the accelerator to the kickdown point.
After 1200 miles. Engine and vehicle speeds can gradually be increased.
Tires:
Drive cautiously during the first 200 miles.
Brake system:
Drive cautiuosly during the first 300 miles.
Clutch:
Drive cautiuosly during the first 300 miles.

Hope this helps.
 
Here is the source of a lot of controversy...and one school of thought on break in period. i am a believer myself. :D

http://www.mototuneusa.com/break_in_secrets.htm
 
When I first ordered my Coupe last year I had a lot of time to kill before the car arrived on the west coast so I did a bunch of searches on the topic of engine break in practices.

Motoman sparked a pretty good debate with his posts but there are dozens of posts from highly knowledgeable mechanics that tossed most of his diatribe into the trash bin. There was somewhat of a consensus on at least one point he made however - the machining on the piston rings is designed to perform a very specific and necessary abrasive action on the cylinder walls during the first couple hundred miles of the engine's life. How to perform that is where almost of the posts I read deviated from Motoman's view.

If I understand things correctly, there is a lot of heat generated in the engine during the break in period and a build of up heat during this phase of your engine's life is not a good thing at all - it will actually cause long term damage to the life expectancy of the engine if carried to excess. At the same time, there is a need to run the engine up to a reasonable level of RPMs (not redline) under WOT conditions (full cylinder combustion pressure) in order for the rings to perform their task of properly preparing the cylinder walls for their long term tasks. The key is to always allow the engine to cool back down after each such run up to make sure that heat buildup is kept at bay. This stage of engine break in really only counts during the first 200 miles or so and after that the machined scoring on the piston rings wears off and there is no further gain from repeating the WOT run ups.

I have followed a lot of different techniques for new engine break in through the years mostly on the conservative side and this was the first time I ever included doing WOT runs during the first 200 miles. They were quite random depending on when conditions permitted stomping on the throttle and I limited these runs to 5K RPMs given that the engine was so green otherwise.

After 13K miles my engine does seem to be running very nicely and a little smoother than most of my last half dozen new cars so I don't have any misgivings about how I went about the task.

After all that, this IS the internet and there are hundreds (if not thousands) of posts/opinions on this topic ranging from driving like your grandmother on her way to church to Motoman with his don't let your right foot off the floor until break in is done. I see no useful basis for my approach being anything beyond my own summary of a lot of people's thinking and my own comfort level with my cars. If you have any doubts whatever just jump onto google with the string "engine break in" and be prepared to spend lot of hours churning through the results. Take posts like mine with a big grain of salt because I am not a professional mechanic who tears engines apart for a living - just another end user who offered up yet another "executive summary" of my own research on the topic.

The only thing that was clear to me after spending seemingly endless hours reading on the topic was that no one could state definitively what the real answer to the question was.......
 
I think that one can find the answer by following the Buddhist "middle path". Don't drive like grandma - but also do not drive like a bat out of hell.
 
You must log in or register to reply here.
Back
Top Bottom