Originally Posted by forsailbyowner
Why in the world did they decide not to put oil filters on the a4. Bet every crank looks bad just from break in metal floating around.
Because the oil sits in a sump that's continuous with the transmission
. It's pressurized, but not in the usual sense as the system is open to the atmosphere via the breather. Very 1940s. There is an internal filter, but frankly, being a low-compression gas engine, the A4 doesn't eat itself very much. You can, if you wish, install a separate oil filter
, but most people just drain out the four litres it takes and pour in a new jug until the dipstick reads "FULL".
When I rebuilt the engine, I changed the oil after ten hours, and now I do it every 25 (which could be once a season if I don't motor-sail, as I tend to have it on for 10-minute "dock to head
to wind" periods, and even going out 25 times a season, it's hard to make 25 hours of runtime). Others change every 50 or 100 hours.