mrkbbd

How are you supposed to break in the motors on cars nowadays? I have been getting conflicting advice, some say it doesnt need it and others say up to 3000 miles. Also, my dealer told me that when they get AMG cars in, they take them in the back and DYNO them, is this safe? or should I tell them not to do it to my car when I take delivery?

mick1

the mercedes manual says you've got to drive slow for the 1st 1,000 miles.

cntlaw

what I was told, it is the transmission which needs break-in.
the engine is already done in the factory.

My garage friend always tell me not to drive over 3500rpm at first 5000km
But that's a bit long and I am tempted.

For first 2000km I would keep the rev under 4500rpm
However, I would progressively increase the rpm at different gears.
And I also avoid to floor the pedal when the engine is cold.

Guess there is no rule

hantzis

Yes, I have heard conflicting stories also. I waited until the ODO reached 1000 miles. Better safe than sorry. I know, a true test of will power Hang in there!

MikeL

Manual says 1000 miles. Generally MB engines arent fully broken in until about 3-5K miles. No engines do not come broken in from the factory. I would suggest that you change the oil after about 1000-1500 miles or so. The engine is new and particles, shavings, etc. are in the oil. My BMW and all ///M cars require a 1200 miles service. Oil, LSD, tranny fluids, etc. are all changed out. Also, if your car is not leased and you care about it, dont follow your service wrench on oil changes. MB says you can go 10K miles with one oil change, but blackstone oil analysis show different. I usually get my oil changed once in between on my MB. I change the oil roughly once every 5K miles. On my BMW every 3K.

cntlaw

yes, after the first 5000km and the oil changed , the car is always 'different'.
I suppose my W211 was really feeling great after one year

vitaman

Mike;
Can you give more details about how the oil analysis contradicts the Manufacturer's recommendations? Especially if tou know anything that applies to AMG's.

MikeL

Over at the BMW forums, If you know about the S54 (m3 motor, high performance racing motor like the AMG) It is a great motor but it has bearing/engine failures. Which results in a kabooooom. If you follow BMW's service indicator as well, it says to change the oil out between 10-12K miles. (MB's about 10K as well) Synthetic oil is good and all, but it doesnt last any where near 10K miles. Anyhow, memebers of the BMW community do frequent oil analysis'. I did this on my MB's and BMW (Initally did this because the BMW engine failures, there is a way to tell if certain levels are too high, then most prob the bearings are bad.) A member with a M roadster did severe oil analysis testing because BMW decided to only recall M3 coupe and cab motors. HE found out that his lead content was extremly high, nearly doubled, means bearings are going bad. He showed the oil analysis to the dealer and pushed them to replace his motor. Synthetic oil is no good after about 5K miles. (www.blackstone-labs.com) Blackstone labs has a base line for cars/engines for acceptable levels of contaminents, etc. 10K miles on one oil change is kind of pushing it. Most of the compound present are heavy metals coming from various parts of the engine. If you know enough about car engine, if a coumpound A is too high that's mean that the part(s) that made of A is wearing off. Goto the blackstone website and order a free kit. They'll give you as many as you like for free. Each oil analysis cost $20 when you send it in. If your car is a lease, I wouldnt worry about it too much. If you purchased the car and plan on keeping it a while, it might be somthing to look in to. We have a CLK55 in our fleet as well, I always get the oil changed half way in between what the wrench says and make sure you dont let them reset it. I think that since car companies offer free oil changes etc, they try to stretch it out as long as possible. Btw, check oil levels regularly, every couple thousand miles, the ///M and AMG burns oil, sometimes as much a whole liter. By the time you light on the dash comes on saying you oil is low, its already too late by then.

neoprufrok

Sorry for the long winded reply, but I have used the following break in procedures on everything from My Civic Si, Audi S4, Audi A4, Acura CLS and Merc C230k and I have never had an engine problem and usually get better than average gas mileage. Again, I apologize for the length... also even though he is talking about the Saturn engines, the general principles should apply - If anyone else knows anything different about Merc's engines, please correct me!

Ben's guide to 4-stroke engine break-in:

The Practice. For the first 100 miles, only take short trips of <15
minutes. Do not rev above about 3500 rpm. Use full throttle in short
(2-3 second) bursts at low rpms (say 2500) - 5th gear on the freeway
is ideal for this. Do not do more than one full-throttle burst in the
same 2-minute period. Avoid driving for more than 2-3 minutes at the
same rpm - if you are on the freeway, vary your speed and alternate
between 5th and 4th gears.

>From 100-500 miles, increase the peak RPM you reach by 200 rpm each
time you drive the car (but don't go higher than redline). Do not rev
to your new peak under heavy throttle; instead, let the engine drift
up to the rpm under light load. For instance, pulling away from a
stoplight, leave the engine in first and accelerate lightly until you
reach the desired RPM, then shift. Continue the full-throttle-burst
procedure. Do not rev the engine high under full throttle, and do not
do either the peak-revving or the full-throttle procedure more often
than once a minute. Avoid driving for more than 5 minutes at any one
rpm - again, alternating between two adjacent gears and varying your
speed will work.

You will notice that each time you reach a new peak rpm, the engine
will be quite loud at that rpm, but after a few runs up it will quiet
down. This is a sign that the break-in is proceeding well. You will
want to have revved the engine to 6500(5500) rpm a few times by the
time you reach 500 miles. At that point I recommend you change the
oil, as most of the metal wear and contaminants from break-in are
released in the first 500 miles.

>From 500-3000 miles (the extended break-in) you can operate your
engine fairly normally. Most of the work is done. You should still
run the engine at higher RPMs on a regular basis (assuming you don't
in the normal course of driving ;-) ) and you should avoid prolonged
high-speed/high-stress operation, like racing or cruising at 110 mph.*
I personally change the oil after 1500 miles since it will be dirtier
at that point that it would be after 3000 miles of post-break-in
operation, but it isn't critical. Be sure to change it at 3000 miles,
however. Although there is some difference of opinion on what KIND of
oil to use during break-in, the general consensus is to use normal
(non-synthetic) oil of the recommended weight (5- or 10-30).

>From 3000 miles onward, your engine is considered broken in. It will
probably continue to "loosen up" a bit over the next 3000-6000 miles,
so look for a small increase in gas mileage. Other than that, your
engine is now be ready for a long and productive life. Enjoy!

neoprufrok

Part 2 (too long for one reply)



***** BEGIN TECHNICAL SECTION ***** [Some of this is what I remember
from articles I have read and discussions. I cannot vouch for the
complete accuracy of what follows, but I believe it to be essentially
correct. If you *must* flame me, please do so in private unless you
think I've made a mistake which everyone need to know about to avoid
doing something unpleasant to their car]

The Theory. The primary goals of engine break-in are: 1) achieving a
good seal between the piston rings and cylinder walls, and 2) allowing
the engine to operate correctly throughout its RPM range. The major
enemy during the break-in period is localized heat buildup, mainly in
bearing surfaces (most notably the crankshaft bearings).

Initial state: When the engine is machined at the factory, many
wearing surfaces (places where parts rub against each other - cylinder
walls, bearings, etc) are purposely machined more roughly than they
could be. The reason for this is that it allows the engine to
complete the machining/polishing as it operates, thus allowing for the
individual variations inherent in any manufacturing process. This
wearing process, when complete, produces parts which will fit together
with very tight tolerances. However, the process also involves a
great deal of friction, which in turn means a great deal of heat. As
metal parts heat, they expand slightly. If the expansion goes beyond
a certain point, the parts will tend to bind with and/or score each
other. This must be avoided.

[To put this in plain english, the parts which rub against each other
are left a bit rough, and as the engine runs the parts will scrape
against each other until they wear down a bit and have a proper fit.*
While they're still in the process of scraping, they can get very hot;
if they get too hot, they will damage each other in a permanent way.]

Since this sort of heat buildup is very localized, it will not show up
on the engine temperature gauge. Therefore, it is important to
operate the engine in such a way that the heat buildup will not reach
a dangerous level. More on this later.

Stress and Variation: Although the engine parts are metal and, as a
rule, quite rigid, they are still subject to slight deformation when
stress is applied. The largest stress in a piston engine is that
produced by reciprocating parts. The forces involved increase with
the square of the RPM. Any deformation will necessarily involve a
change in some tolerances inside the engine. Thus, in order for the
engine to operate properly over a range of RPMs, it is important that
it be exercised over this range during the break-in process so that
the wearing parts will experience the range of tolerances they will be
subjected to during normal (post-break-in) operation. Further, for
the wearing surfaces of reciprocating parts (most notably the piston
ring/ cylinder wall interface) operation at a single RPM for an
extended period of time will cause the machining process to progress
significantly further within the confines of the part's range of
travel without progressing at the point just outside that range, thus
building up a small ridge of metal just above the point of maximum
excursion.

[In order for your engine to run well from 1000 to redline, you need
to operate it at all those rpms while it is breaking in. If you
don't, the parts won't be used to working at the rpms you neglected,
and they won't work as well at those speeds]

Piston Ring Sealing: The seal between the piston ring and the cylinder
wall is crucial to getting good economy and performance from the
engine. A bad seal will allow more blow-by, reducing the amount of
power the engine can produce with each power stroke and thus reducing
both its horsepower and fuel economy, as well as allowing combustion
gasses to get into the crankcase and contaminate the oil AND allowing
oil to get into the combustion chamber and be burned, producing the
characteristic blue-smoke-from-the-tailpipe syndrome (note that oil
can also get into the combustion chamber via the valve stem guides,
but that's not something we can do much about during break-in). The
key to getting a good piston ring seal is high combustion chamber
pressures. Embarrassingly, I don't know why (can someone fill me
in?). High combustion chamber pressure is produced under hard
acceleration; also, the lower the RPM the longer that pressure is
maintained during each power stroke. SO - to get a good piston ring
seal, hard acceleration at low RPMs will give the best results.*
Since hard acceleration also produces more heat and more stress
(leading to friction and still MORE heat), it should only be used in
brief bursts, followed by a couple of minutes of "normal" low-stress
operation to allow the heated parts to cool down.

Localized Heat Buildup:
As previously mentioned, wearing parts will produce inordinate
amounts of heat as they polish each other. This produces local points
of intense heat inside the engine, with temperatures far higher than
the engine as a whole (which shows up on the temperature gauge) or
even of the surrounding parts. The most susceptable points in an
engine for this kind of heat buildup are the crankshaft bearings,
which must withstand enormous stress and pressure. If the bearings
are allowed to get too hot, they will expand to the point of scoring
each other or (*gulp*) binding, producing a spun bearing. During the
initial stages of engine break-in, there is no satisfactory way of
keeping these bearings cool during even mild engine operation except
to turn the engine off after every 10-15 minutes of operation and
allow the bearings to cool down.

The theory I have outlined about should now be sufficient to explain
the "practice" section of the break-in instructions. For the first
100 miles, keep the rpms low and the trips short to minimize the
stresses and heat buildup in the bearings, and use short full-throttle
bursts to seal the piston rings. From 100-500 miles, gradually
increase the RPMs to allow the wearing surfaces to correctly mate, and
continue using full-throttle bursts to ensure ring sealing. Use
cooling periods (the 1-minute rule) to minimize the heat buildup
produced by the high RPM operation and the full throttle bursts. At
500 miles, change the oil to flush out all the metal particles
produced by the wearing process.

I hope everyone finds this information useful. If you have comments
which are of general interest, please post them - if you just want to
flame me for making a mistake, please email me so that we don't make
everyone endure a huge firestorm. I should also note that I practice
what I preach - at 7000 miles my CBR is more powerful than anyone
else's I have ridden and its oil is clean after 2000 miles of
operation, while my Saturn SL2 at 10,000 miles is getting 29 mpg
overall and consumes no oil at all.

Schiznick

How about we just follow the sticker in the window?

neoprufrok

Someone pointed out correctly that this procedure works for a manual transmission. Thus, for the AMG speedshift version, it may not work as well given the fact that Merc says no use of the manual selection until after 1000 miles. I still think it would be beneficial to vary engine speeds if possible while driving the car initially.

Thanks vitamin for your insight!

viper

You guys are all wrong. Drive the car for what it is - a high performance sedan. The first 20 miles determine the longevity of your engine. If you drive it too easy, the piston rings don't get seated properly and you risk contamination of your engine oil from that point on. The idea that you must baby the engine for the first 1000 miles was back in the old days when part tolerances were very sloppy. You people are living in the past.

neoprufrok

Agree with you on two things:

1) Too many people baby their car too much in the first 1k miles.
2) Piston ring seating/sealing is a very important factor for future performance.

On your other points, I'd like to know where you are getting this infromation from, or just what your reasoning is. I would be more inclined to believe you if you could point me to the knowledge and thought that led to your conclusions.

Thanks.

viper

My information comes from experience. I work in software development on engine test systems for one of the Big 3 domestic manufacturers. I know how engines were built and tested in the early 80's and how the assembly and test methodology has changed over the years. Cold and hot testing of engines was in its infancy back then. Today the quality of engines that are produced is light years ahead in durability and efficiency.

neoprufrok

Thanks for the info. I didn't mean to sound distrusting, but its hard on the internet to know who's telling the truth and who's just blowing stuff out of their ***. So in the C55, how would you recommend driving specifically in the first 20 miles? Vary the rev ranges? WOT at all times? Also, what if the dealer already puts 25 miles on the car at the time we take delivery?

Thanks in advance for any help you have.

MikeL

if what your saying is 100% accurate about break in methods, why did my BMW come with a huge warning sticker on the windshield stating exactly as follows,

Betriebsanleitung beachten!
"-Break-In Instruction- "
-up to 1200 miles/2000km:
no full throttle
max. engine speed: 5500 rpm min
max. speed: 106 mph/ 170 kmh

-up to 3100 miles/5000KM:
max. speed only for short periods
max. constant speed: 137 mph/ 220 kmh
max. speed only for short periods

Im pretty sure the master techs over at BMW ///M know what they are talking about.

viper

Yes they do know what they are talking about. And what they are saying is that the inline six engine that they have tweaked over the years to give over 300 HP is at the edge of its design envelope. Push this engine too hard too soon and you will probably cause some problems. Their warranty claims have most likely proven this out so they encourage you (ie warn you) not to push the engine into oblivion. While I am not privy to the specifics of their engine design or limitations I have heard of M3 engines blowing up.

viper

Run the engine hard during break-in just don't abuse it. Nobody said said you should approach redline. If you baby the engine too much you won't expand the piston rings enough and you end up leaving a thin film of oil on the cylinder walls. This film will oxidize with the high combustion temperatures and will induce glazing of the cylinder walls thus leading to high oil consumption. Glazing can only be corrected by rehoning the cylinder walls at considerable expense and inconvenience to you. You certainly don't want to have this done to a brand new vehicle.

neoprufrok

Thanks for the info viper!

cntlaw

Okay Viper , sounded convincing , I am at 2200km now; still fairly baby with the monster, I am not giving the GTR, M3 a chance starting from tommorrow
Cheers

cnt