Quote:
Originally Posted by RockCrusher
Interesting to learn BMW calls for replacing the plugs.
I recall with my Porsche cars the engine oil drain plug required a sealing ring, not a crush washer. And this was not to be reused.
The reason was the sealing ring — made of IIRC a silicon bronze alloy and very hard and very flat and very smooth — was the sacrificial item in the drain plug/engine oil pan (or in the case of my Turbo oil tank) partnership. Upon removing the drain plug the sealing ring would have a slight but noticeable depression from the drain plug on the side the drain plug was tightened against. Re use of this ring would have that marred the drain plug surface or the sealing surface of the oil pan/oil tank.
This over time would cause the very smooth/flat surface of the drain plug and oil pan/tank to become damaged. Techs told me the result was after a while the plug/oil sump sealing — even if the old ring was replaced with a new sealing ring — was compromised and there was a bit of oil wetness around that area. I always replaced the sealing ring. My Boxster's oil sump/drain plug area was dry even at 317K miles and with oil changes every 5K miles after approx. 63 oil changes. The Turbo had 161K miles and thus had 32 oil changes. Its oil drain plug and where it plugged the tank was dry too.
Not only did the oil sump not leak the oil drain plug was oil tight too. In spite of being aluminum I only had to buy one oil drain plug the whole time I owned the car. I took the car to a oil change place — the dealer was booked — and supplied the oil, filter, filter o-ring, and oil drain plug [...]
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Yeah these bmw plugs also have a built in sealing rubber (green colour) and I think for that reason they call for a new plug. I’ve seen at least a couple members here post about a bit if a leak after they went in for the break in service. I have a feeling it might be from reuse of the plug and/or perhaps wrong torque spec being used… but they all said tightening the plug a little more seemed to have stopped the leak…