Quote:
Originally Posted by epapp
Update: breaking the plug, rotating it back and fourth a bit and retightening solved the leak.
Why so temperamental?
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Told ya so.
It all has to do with the position that the crush ring makes final contact when the unit is tightened. If it rests on a more uneven portion of the sump plate, you'll stand a better chance of a leak. If it doesn't, it'll often seal right up with no issues.
Instead of doing this procedure of breaking torque, then re- torquing, people always feel the need to wrench down on it, and that creates bigger issues that can sometimes compromise the unit immediately. Tighter is better, right? No, thats why the unit has a torque spec.
I have had the same thing happen with factory drain plugs, which was one reason why the magnetic plug was developed in 2006. In fact,
I learned this technique of breaking torque, then reapplying it with stock drain plugs, not the LN unit, or my MCD.
That said, over time we've seen a degradation of some of the crush rings too. These all are genuine, but some have an inner diameter thats .25mm too large, which makes ID of the crush ring not conform to the OD of the drain plug concentrically. This further aggravates the issue, and makes it more of a risk of not seating perfectly. The same thing holds true with the crush rings that seal under the chain tensioners, tons of issues with those, (genuine Porsche) to the point that we had to have our own manufactured.
Another variable is the oil thats used... One reason I hate Mobil 1 with a passion, is because it will leak when nothing else will, due to its composition. Oils that use an additive package that includes Chlorinated Paraffin always tend to leak worse than anything else. I have seen times when an engine would have leaks with M1, and the oil was changed, and the leaks went away. This is especially true with aircooled Porsche engines. Some additive packages based on esters will also cause this to be more of an issue, so even oil is an uncontrollable variable.
I believe in owning any mistake, and in my world I take it on the chin all the time with new developments that don't work out in testing. At the same time, when you have scenarios like this, that have a ton of technical variables present, each case can have a different root cause. Luck plays into it too, if the crush gasket lands in the wrong spot you'll have a leak, and that could be Porsche's fault (machining of sump plate, or crush ring), a driver's fault from hitting some road hazard with the sump plate, or the installers fault, only because he touched it.
This also means it could be my fault, or Charles' fault, too, and everything is always our fault. When the finger pointing exercise begins, the part that was added on always get the finger first- no matter what. No one can manage, or control these variables. In this type of situation, all that can be done is supporting the sale, and offering a replacement unit, hoping thats good enough. This thread has proven that its not good enough.