tetherM5

I have a 2000 M5 that was build in 10/99 with around 65K on the clock. The car performs excellent, never had any significant issues other then having the accumulator upgrade completed on the VANOS, a replaced smog pump, and new valve cover gaskets. It does consume a liter of oil between 500-1200 miles depending on my driving style. I bought this car with about 50K on it and learned that it was one of the first M cars delivered to a local M5 dealership, and that the owner of the dealership drove it for the first 10K miles. My independent mechanic is someone who I especially trust. He works only on BMW's and Porsche's and has a lot of experience building custom engine applications for racing.

We were talking about the oil usage on my and another customers car and he recognized that the oil rings used on the initial S62 engines were hemispherical or something to that extent. He believed that the reason why certain cars (Even 01+ cars) burn more oil then other was the way they were broken in - actually not being driven hard enough during the initial 5-15K miles. He is a big proponent of a new or rebuilt racing engine needing to be driven hard after the first couple hundred miles to make sure that the oil rings sit down properly. He said that the rings used in the initial engine were closer to what is used in racing applications and that these engines are built to push more oil into the cylinder so that there is a more significant oil cushion at high RPM's. He said that Porsche's burn oil just as much, and that his racing applications drink oil at the rate of a quart every couple hours or so. He told me that the 10-60 oil is used by Porsche as well and he thinks that its just too initially thin, he quips "it pours like water into the crankcase."

My car is under warranty, and while I can have the engine torn down if the problem gets worse, my mechanic thinks that is a bad idea. Right now the cars compression, horsepower, idle, everything are perfect and if I have the engine torn down just because I am displeased with having to put oil in the engine it could end up being a Pandora's box, especially since it would have to be done by dealership mechanics (which I honestly don’t trust.) He is confident that the thicker oil will help to finally seat the rings and reduce the blow-by enough to significantly decrease the consumption. He told me he has seen older generation M cars burn oil up to near 100K and then all of a sudden, they stop.

I am going to try the Swepco out for a couple thousand miles and see if that works. He has another customer who is also going to try it who has an 01 with a good burn rate as well. It would be great if that resolves this!

Digi

On engine breaking-in techniques and theories -- BMW also has much experience in this field, and they have certain recommended breaking in procedures for their engines which are specified in the owner's manual. I know your mechanic and other experts have other ideas. I'd use the BMW technique.

tetherM5

I believe the BMW break-in procedures were low intensity use for the first 1000 miles or something like that? I don't think my mechanic has a problem with recommendation on the initial break in procedures, but after that people drive the cars like they are around town commuters and that results in the ring issues.

Also, what car company in their right mind would EVER recommend driving the engine at its limits of performance regularly to assist in break-in? Even if BMW recognized it to be beneficial for the engine there would be NO way that it would make its way past the legal group.

Digi

I don't think your mechanic recommeded that procedure either. You can always adjust your engine speed to spirited driving levels, even if you don't speed above the posted 70 MPH limits You can break the car in by rapid acceleration and varying engine speed at or near redline by using gears, if that is the intent. I think increased oil usage would result in a BMW, as well as decreased engine life. Each to their own beliefs. Cheers!

jordantii

This is from the M3 SIG a discussion about engine break in. Thought you would like to see it:


with all this talk of engine break in, rings, etc. I thought
Id publish some data for gr. A motorsport engine. below you
will see how the block was prepared/honed and then the breakin procedure.

a few things to note:
1. initial break in takes 2.5 hours with increasing rpm from 2800
to 5500 rpm, and increasing load.
2. then 15 min of varying load. then a full run.
3. idle is setup after initial break in.
4. it is often recommended to immediately bring the rpm to > 2500 rpm
after installing new cams. step 1 satisfies this condition.
5. now they may or may not dump the first oil, but they didnt do it until
step 1 and 2 were complete.
6. engine broken in, and they proceed to final site for site power
measurment


Anyone like to compare this with their results, dependent on hone
finish and rings ?


http://www.mototuneusa.com/break_in_secrets.htm

most of that made sense, it definately agrees with a quicker
vs. longer breakin.

That guy said 80% of the ring is set within the first 20 minutes
(with a rough hone finish) and he does 9 rolling dyno runs with varying
throttle (40-60%, 40-80%, fullthrottle). BMW Motorsport allowed
themselve more time and used fixed rpms/loads (brake-dyno).

On the street, the author also seemed to indicate, rings set 80%
in first 20 min. and then up to 1000 miles for the last 20% due
to less controlled running conditions. On track the complete
setting of rings happen quicker and is the best way to break in
the engine other than the dyno.

He didnt say how much oil consumption to expect after the rings have
set 80%. When I look at my engine, at 300 miles it had seen already
8000 rpm, but it consumed oil noticeably on the track.
It took 600+ miles before the consumption went down to low levels.
That corresponds to approx. 3 hrs of running time with varying rpms
from 4000 to 7000. So by this article the actual break-in took
longer than it should have, or perhaps I risked not getting
a good seal. any ideas, similar or alternate experiences?


BMW Motorsport specs:
-----------------------------------------------------------------


block preperation for honing:
-- block with timing chain housing torqued 15 Nm
-- torque plate with zyl. head gasket
torqued in 3 steps: 50 Nm, 80 Nm, 100 Nm
-- main bearings installed 20 Nm (+/- 1), 55 deg. (+2 deg.)


honing in 3 steps:

initial hone
bore diameter - 0.030 mm
honing stone EHU 518 (C 30 J 64)
removal of oilslack on used block: C 30 J 85, used only for this purpose

form hone
bore diameter - 0.010 mm (+0.005 mm/-0.000 mm)
honing stone: C30 J 85, form and dimensional correction
according to honing pressure
tolerance for roundness 0.005 mm.

finish hone
honing stone C 30 J 85
30 strokes

clean block and all oil channels thoroughly


wall finish:
-- median roughness: Rz=1.0 - 3.0 micrometer


----------------------------------------------------------------

breakin procedure on dyno (2.5 hour run-in program):
[NOTE: do not re-torque the cyl. head]

RPM Load (Nm) Run-time (min.)
1 2800 60 15
2 3000 70 15
3 3500 75 15
4 4000 80 15
5 4500 105 20
6 4800 95 25
7 5000 115 25
8 5500 125 20

followed by 15 minutes of varying loads, first power run,
idle setup, compression test

Power measurements:

RPM
9 5000
10 5500
11 6000
12 6250
13 6500
14 6750
15 7000
16 7250
17 7500
18 7750
19 8000
20 8250
21 8500

max oil temp: 125 C
max water temp: 80 C
max water pressure: < 1.0 bar
max oil pressure: > 4.0 bar
fuel pressure: 5 bar

----------------------------------------------------------------

engine warm up on broken in engines:

RPM LOAD (Nm) oil temp.
2800 <60 until 40 C
3000 60-80 until 50 C
5000 80-120 until 80 C
> 80 C full thottle possible