Porsche 928 S4 Service

John Pirtle, February 2, 2001
http://members.rennlist.org/pirtle

Oil Change

There is nothing special about changing the oil in a 928, other than you'll need a bit over TWO gallons.... (8.0 liters = 2.11 gallons = 8.4560 quarts) There is a very interesting article in the 928 Owners Club Journal on the 928OC web site discussing synthetic oil. Aside from explaining the benefits of a synthetic, a case is made for longer change intervals since a 928 engine has about twice the amount of oil found in many other car engines. Many enthusiasts have suggested simply changing the oil in the Spring and in the Fall, while others prefer sticking to every 3000 miles.

As a believer in synthetics, Mobil 1 is in my 928, my minivan and my lawnmower. All three engines have run amazingly quieter after the switch. The first and second changes with synthetic may show the oil dirtier and blacker than with conventional oil, but this is due to the synthetics' higher affinity for metal which displaces dirt and varnish.

Items needed:
• oil - Mobil 1 15W-50 preferred, get 9 quarts
• filter - Porsche is recommended and just as inexpensive
• filter tool - for about $6 you can get the Porsche cap that perfectly fits over the Porsche oil filter and makes removal easy
• a large drain pan that can easily hold 8-9 quarts
• drain plug gasket - might as well change it every year for $1
• oil filler cap gasket - check yours since these shrink when cooked. The 928 engine is quite sensitive to vacuum loss, even in the oil system. Check that your cap, dipstick, and other oil/air hoses seal tightly.

Procedure:
1. Warm the engine to operating temperature.
2. Raise the entire car level in the air. Drive up on ramps or put jack stands in front, and jack the rear. A level car will empty all the oil out of the pan.
3. Remove the oil filler cap.
4. Remove the belly pans if you have them.
5. Position the drain pan, loosen the 15mm oil pan drain plug and stay clear of the hot oil.
6. Remove the oil filter being careful not to spill oil or burn yourself. (The Porsche oil filter removal tool needs a 27mm socket.)
7. Wipe a little fresh oil on the new oil filter gasket.
8. Hand spin the new oil filter on and simply snug it.
9. Replace the drain plug using the new gasket - tighten to 50Nm (36lb/ft).
10. Pour in 8 quarts of oil.
11. Allow a couple of minutes for the oil to drain to the pan, and check the dipstick level. The level should be between the low and high marks (the difference between the marks is approximately 1.5 liters, or 1.58 quarts).
12. Install the new gasket in the oil filler cap and replace the cap.
13. Remove the fuel pump fuse (#42 on my '87) and hit the ignition. Allow the engine to spin for several seconds and circulate the oil, build pressure, and fill the oil filter.
14. Replace the fuse and check for leaks.
15. Start the engine and check for leaks.
16. Go for a drive and check for leaks.
17. After the engine cools, check the oil level and add if necessary (likely almost ½ quart). Do NOT overfill!
18. Over the next couple of drives, check for leaks!

928 S4 Page

John Pirtle
March 3, 2001