East West European Imports - BMW Mercedes Porsche Ferrari

Figure 1, BMW E46 Ignition Coils

BMW ignition coils do go faulty from time to time. The ignition coils shown in figure 1 were from a 1999 BMW 323i.
The vehicle came to us with a Check Engine MIL on. The technician noticed that there were ignition misfires present.
Running module scan with our BMW GT1 diagnostic system confirmed the technician's thoughts. The GT1 revealed
that number 4 cylinder was misfiring.

The technician removed the number 4 ignition coil to inspect for any irregularities. The spark plug was properly
torqued, but the ignition coil itself had signs of arcing, and the plastic housing was melted as well. See figure 1, red
circles. With this discovery, the technician decided to remove all of the ignition coils for inspection. Sure enough, all
of the ignition coils were suffering from the same affliction.

This vehicle also had fault codes for oxygen sensors. The technician recommended to the customer that the four
oxygen sensors, six ignition coils, six spark plugs, and the fuel filter to be replaced. Also recommended was
updating of the DME with the latest software version. The customer authorized the repairs. After the repairs were
completed, engine performance was smooth and powerful, and no fault codes returned.

Mercedes 722.6 transmissions are pretty durable
mechanically. However, the Achilles heal of the
722.6 is the conductor plate coupler. See figure
2a, red circle, shown disconnected from the
transmission.

The conductor plate coupler provides the
connection to the wiring harness for the
transmission control module. See figure 2b, black
box.

The issue with the conductor plate coupler is that
it is prone to leaking. The transmission fluid leaks
into the coupler, and creates electrical shorts.
This situation can cause a check engine MIL,
irregular shifting, limp mode, or damage to the
transmission control module.

In some cases, the transmission fluid can leak all
the way up to the transmission control module,
through approximately 3 feet of wiring. See figure
2b, red circle, transmission fluid leakage.

As is the case with many european automobiles,
Mercedes have very sensitive electronics.
Electrical shorts or spikes can "zap" out a control
module in no time. Even though fuses are in place
to protect the electrical components, they don't
always react quick enough. Its common to find a
"zapped" out module and all fuses in perfect
condition.

The BMW E46 3-series model uses two separate
fuel tanks. The fuel system uses a jet system to
transfer fuel from the left tank to the right tank.
When fuel level irregularities come about, Our
BMW technician can access the amount of fuel in
each tank via instrument cluster. See the
red-circled area in Figure 3a. The first three digits
(015) is the amount of fuel in liters in the left tank.
The last three digits (327) is the amount of fuel in
liters in the right tank. 1.5 liters + 32.7 liters = 34.2
liters. The fuel capacity for the E46 model is 63
liters, 34.2 liters is equal to slightly more than 1/2
the fuel capacity. Notice the fuel gauge in Figure
3a; the needle is slightly past the half mark, so this
fuel gauge is reading accurately.

Mercedes motor mounts are
filled with very thick oil. The oil
dampens the vibrations from
the engine. Over time, the
rubber bladder containing the
oil can stretch or crack,
allowing the oil to spread out
or leak. The result is a
"sunken" motor mount. See the
red height reference lines in
Figure 4a. The motor mount on
the right is an old sunken
mount, and the one on the
right is a new updated style
motor mount (both mounts are
for the same vehicle).

Sunken motor mounts cause
the engine to sink in the engine
bay. This situation changes
the geometry of the driveline.
The result is added strain on
the transmission, engine
wiring harness, and hoses.
also, vibrations from the
engine transmit into the
chassis, which can fatigue
and loosen fasteners.

There are two separate air filter
designs for the BMW E39 and E46
chassis 6 cylinder engines.
Figure 5a displays the two
different designs. The air filter on
the left is a "light duty" filter. The
air filter on the right is a "heavy
duty" filter with a layer of black
foam attached to the underside.

To avoid potential MIL (Mafunction
Indicator Lamp) warnings, we
prefer to install the heavy duty
filters on the 6 cylinder E39 and
E46 chassis cars.

Under certain circumstances, the
light duty filter can have a
negative affect on the air/fuel
mixture. The mass air flow sensor
can compensate for the less
restrictive filter, but this shifts the
calibration closer to the limits of its
operation perameters, making it
easier for MIL warnings to pop up
on the instrument cluster.

The air filter on the in Figure 6a is
an air filter from a 1995 Porsche
993/911. The filter was not
replaced for quite some time,
resulting in an extremely restricted
filter. In fact, this filter was
partially "sucked" into the airbox
by the choking engine!

The air filter on the right is the
same filter (albeit new). Notice the
white base flanges compared to
the distorted flanges on the old
filter.

We recommend replacement of
engine air filter(s) on all
automobiles at no more than
30,000 mile intervals (or cleaning
and oiling if its a K&N filter).

Dirty air filters rob your engine of
performance and fuel economy,
so keep track of the condition of
your air filters.

Figure 7a is a right side
convertible top rail mechanism
from a 2005 Mini Cooper
Convertible.

The area circled in red are broken
parts where the cable anchors to
the mechanism. Over time the
connection fatigues and fails. The
result is non-release of the
convertible top on the side that the
cable breaks.

The Mini Cooper oil filter cap on the right in
Figure 7 is missing it's plastic cage. The
plastic cage inserts into the oil filter, and
can sometimes be pulled out with the filter.
If care is not taken by the technician, the
plastic cage can easily get discarded with
the old oil filter.

The oil filter cap on the left is a new cap
complete with the plastic cage.

Without the plastic cage in place, the
spring in the cap will tear through the end
of the oil filter, and possibly cause a
change in oil pressure as a result.

The Porsche 928 in Figure 8 was
subjected to incompetent past electrical
repairs. With older automobiles,
electrical wiring problems are common.

Typically, older automobiles have had a
few owners, and somewhere in the
history of the automobile an owner will
add electronic accessories. More often
than not, the electronic accessory will
appear to be nicely installed from the
outside. "Behind the scenes," it is
common to find poorly connected wires,
unorganized wires that look like a bunch
of spaghetti, and accessories being
powered by incorrect systems (i.e.
tapping into the power for the ESP
system, or ABS system for example).

Tapping into certain systems to power
up an electronic accessory can result in
falsely activated dash warning MILs,
and/or damaged control modules.

Professional technicians agree that
aftermarket accessories should not be
installed on any high-end motor vehicle.

Long oil change intervals is a
major cause of sludge build-up in
engines. Figure 9a shows the
sludge build-up and discoloration
in the cylinder head and inside the
valve cover. The vehicle in the
photo is a 1999 BMW 323i with
157,936 miles.

Sludge inside the engine restricts
oil flow, and causes accelerated
wear of internal engine
components.

In some areas of this cylinder
head, the sludge was 1/2" thick!

Figure 9b is a detailed view of the
same engine shown in Figure 9a.

If the owner were servicing this
vehicle with engine oil and filter
changes every 5000 miles or less
with good quality oil, the internal
parts of the engine would be
bright aluminum with no sludge
build-up.

Figure 10 shows a separated oil
filter. This oil filter was found on
the same BMW engine shown
above in figures 9a and 9b.

A combination of a low quality oil
filter, and long oil change intervals
has caused this filter to break
apart. Smaller pieces of the filter
are likely scattered throughout the
engine, which can cause a
restriction in the oil galleries.