if you have an '05 to present five series (E60or E61wagon), its gonna have
the new service schedule that is called CBS, or condition based service. this
just means that the car has warnings for all the mentioned items, and it will
throw a message up on the I-Drive screen to tell you to get your plugs
changed, air filter, brake fluid flush, etc.. everthing pretty much has its
own light / message. there is no fluid change interval on the diff. that i've
ever seen, and i am a BMW mechanic. the M cars get a 1,200 mile break in oil
change for the engine, diff, and trans, but thats it. i'll look at the
checksheet but i dont even think they want you to check the level.
the whole "lifetime" term is kinda vague with bmw. even the instructors at
the bmw classes say that its a loose term that doesn't exactly translate to
the "full lifespan of the vehicle"
i cant wait until they come out with some lifetime engine oil, ha ha.

For my 2003 Z4 3.0, the time/mileage service items are on page 9, also below
Inspection II (which is the same as Inspection I except for replacement of
the engine air filter).  They are similar to yours:
 Brake Fluid (2 years)
 Oxygen Sensor (100K miles)
 Spark Plugs (100K miles)
 Auto Trans Fluid (100K miles)
But, there is no mention of coolant except as an Inspection I "Engine
Compartment" item to check for leaks and top off, if necessary.

Since your 530i has the "old" schedule, I wonder whether the 2003 330i and
subsequent (2004~07) 6 cyl. models call for a 4 year change, although the
note at the bottom of page 5 states that "Maintenance items and schedules
stated herein reflect the combined recommendations for all 2003 model BMWs,
and are subject to change."

BTW, I asked the service manager at the time about it & he replied that it
must now be "lifetime".  Needless to say, I'll be changing the coolant at 4
years and putting Red Line in the transmission and differential at around
50,000 miles.

Tom K.

You might double check that.  On my 2003 530i (same engine as Z4) service
and warrantee handbook there's a page (page 8, right below Insp II list)
that lists brake fluid (2 yrs), cooling system (4 yrs), O2 sensor (100K),
Spark plugs (100K), M-mobility System (3 yrs) and Auto trans service (100K
... was "lifetime" on 2001 cars, nothing changed except BMW reevaluated the
wisdom of "lifetime" fill).  The next page has a chart that has blocks for
service performed entries which includes those items.

I would also suggest the diff, trans and p/s fluids be changed at regular
intervals.

I strongly recommend you check the pre-free-maintenance service schedules
for our cars.  They're more conservative and likely to contribute to better
long term service and reliability.

R / John

Not necessarily.  My 2003 Z4 maintenance schedule includes no coolant
changes - it's "lifetime"!

Tom K.

Not unless the float keeps trending downward.  I'd have it topped off and
check the level every day or so for a couple weeks to make sure.

If your car is in the U.S. you might still be in the 4yr/50000 mile free
maintenance schedule window.  Your dealer will top it off for free.  Or you
might DIY.

According to the service schedule, your car should have the coolant drained
and refilled at 4 years from date of manufacture, that might be about now.

R / John

The owner's manual for my 2003 530i says that the proper coolant level
is when the upper edge of the float is even with the top of the filler.
Mine winds up about about 11/2 inches below that, but the temperature
gauge doesn't register any overheating on long trips.

Is this any cause for concern?

Thanks,

Ambrose