They get no respect. Water inevitably gets in your engine oil and sits on the sheet metal under the oil. Hard to believe that such a well-lubricated tray could rust from above, but the water sits below the oil and does the damage. (Remember, you need to change your oil at least once per year to get the water and sludge out. Even though you add quarts of oil through the season, you still have to change it.)
Then you beat the pan to death by sliding it around on your garage floor (when the engine is out). Or by leaving your removed engine on damp concrete. No wonder they are often pin-holed.
1275 pans are getting more rare (they’re not the same as 948 pans), and this week we repaired one for one of the engines we are building. Above, you can see the pin holes along the spot welds for the baffle in the oil pan. Ken cut out the sheet metal and welded-in a new patch as you can see. The patch piece was harvested from another beat-up 948 oil pan!
If you are building up an engine, make sure to check your pan for pin holes. You will often see the perforations along the baffle seam as shown in these photos.
As parts become more worn and scarce, more fabrication and parts rescue is needed!