I have recently replaced the aluminum oil drain plug with a steel one.
I've read that steel plugs are not recommended as mating steel with aluminum (oil pan) can lead to corrosion/galling that can destroy the threads. Should I be worried about it?
"Stainless steel fasteners in aluminium plates or sheets are normally considered safe, whereas aluminium rivets or bolts holding stainless steel parts together is an unwise combination, as there is a practical risk of corrosion."
Does this mean I'm safe here?
What about galling? I've read about that too but it's not totally clear to me what it is and when it happens.
The question is which piece would you rather replace? The plug or the pan? If you create corrosion the less noble metal is the pan so it would be first to corrode and lose material possibly the threads.
What I'd really be concerned with is if the plug is overtorqued you will be replacing the oil pan, rather than a cheap plug.
Galling generally occurs with 2 similar metals that are torqued without adequate lubrication. You can go buy 2 stainless pipe fittings, torque dry and they will most likely never come apart again.
I always wanted the plug to be softer than the pan, always used a new crush washer and took care not to over tighten it. I'll confess to never using a torque wrench but I never had a problem or a leak with my hand tightening estimation.
Can you describe why you changed to a steel drain plug?
I changed oil and bought a magnetic plug made of steel. I didn't even know there were different materials used until I removed the original aliminum one. Still I chose to use the magnetic one and only after it was fitted did I some research.
I applied 35 lbft torque using a torque wrench.
Do you think I'd better put the original plug back? If so how urgent is it? Is it ok with the next oil change?
You should not be using a steel or stainless steel drain plug on these cars. Porsche purposely use an aluminum plug that is softer than the sump cover to reduce the possibilities of the plug tearing up the sump cover. Next oil change, go back to an aluminum unit.
__________________
“Anything really new is invented only in one’s youth. Later, one becomes more experienced, more famous – and more stupid.” - Albert Einstein
You should not be using a steel or stainless steel drain plug on these cars. Porsche purposely use an aluminum plug that is softer than the sump cover to reduce the possibilities of the plug tearing up the sump cover. Next oil change, go back to an aluminum unit.
I changed oil and bought a magnetic plug made of steel. I didn't even know there were different materials used until I removed the original aliminum one. Still I chose to use the magnetic one and only after it was fitted did I some research.
I applied 35 lbft torque using a torque wrench.
Do you think I'd better put the original plug back? If so how urgent is it? Is it ok with the next oil change?
Are you sure it's not aluminum with a magnet attached in the middle ?
First time you drain the sump you'll get oil all over the threads of the plug and unless you go to extraordinary effort to clean this off, you'll have threads nicely protected from corrosion.
The torque figure for tightening the plug is what's required to crush the crush washer--you're not stretching the plug--and that washer then serves as a one-time-use lock washer. Point being, oil on the threads doesn't hurt.
The threads in the pan can deal with the minimal force that's applied to them, as most of the force is absorbed by the crushing of the crush washer.
Don't reuse crush washers ... which ought to be obvious. Don't omit the crush washer either.
__________________
Kent Christensen
Albuquerque
2001 Boxster
2007 GL320 CDI, 2010 CL550
2 BMW motorcycles
1998 Porsche Boxster
Linear Mode
