Cost of repair Audi BMW Saab...(crossposting)

eBob.com wrote:

> That's interesting. Since all of the brands of cars which I have
> owned have had them, I just assumed ...
>
> Anyway, how 'bout educating me on two things. Just exactly what do
> timing belts do? (Yes, I am pretty dumb in this area.) And what do
> the BMWs w/o timing belts have which perform that function?

A timing belt drives the camshaft and valves, by taking power from the
crankshaft. The other alternative is a chain and sprockets, which all newer US
model BMWs have. A few cars like Ferraris have gear driven valvetrains.

The only US model BMW engines with timing belts are the "small six" engines,
which are in the 80s 3 Series, and some 5 series cars -- the 325e, 325i, 528e,
and early 525i. The rare 524td is also a small six w/ a belt.

Matt O.