danby

Hey all, I just did my first DIY oil change on my Cayman and a few days later noticed that there is a very slow leak from the drain plug (no oil on my driveway yet, but it's seeping on the oil pan). I've done dozens of oil changes on other vehicles without issue, and replaced both the bolt and washer during this oil change and torqued to spec. I didn't think to inspect the pan seating surface.

I've searched around on rennlist and seen lots of suggestion (teflon tape, RTV silicone, rubber gasket washer, etc.) and am at a bit of a loss as to what to do. I'd rather not dump all my clean oil if I can avoid it, so I'm looking for suggestions for what I might be able to do.

Extra Background:
I did notice during the oil change that the washer that I removed had some residue on it which looked like RTV red to me. The previous oil change (first one under my ownership) was done by a reputable, independent Porsche shop, and it was their first time seeing the car. I contacted them, and they claimed that they do use teflon tape on the bolt because of these cars' drain bolts to leak.

subshooter

At this point, I'd retorque the plug as a check and do it while the engine is both hot and cold. Wipe the area well and see if the oil comes back. If it is still dripping after this, then you will have to drain the oil and replace the crush washer after thoroughly cleaning the seating surfaces.

okie981

Always clean all mating surfaces of the drain plug, always use a brand new sealing washer made to Porsche OEM spec (yes, it matters, yield strength properties of the metal), and always torque to spec and make sure the washer is centered around the plug as you tighten. If you do these things you will not have leaks.

gedwin

Don't know what they mean by "these cars' drain plugs leak". I've owned 986, 987.2, and 981 Boxsters, putting approx. 200k miles on them combined, doing all of the oil changes myself, and none leaked. Never used sealant of any kind, always torqued with new seal/washer.

Ok, had 1 leak caused by a cracked drain plug, but I don't count that. I may have reused the plug too many times. Replaced the plug, solved the issue. You could check for that, or there could be damage to the sealing surface of the pan. But no, they do not normally leak.

danby

Thanks for the suggestions. I might just need to suck up the extra oil change so I can inspect what's going on.

Kitc2246

I would buy a new oil drain pan and reuse the oil.

Sajan

torque wrench is good? maybe it needs to be calibrated?

danby

I'll double check but it's pretty new and the torque felt about right based on my experience.

New drain pan may be a good option to save the oil. I might also just live with it for a few months and do my next oil change a little earlier than I would normally.

yebokmj

I had a similar problem with my LN Engineering magnetic oil drain plug, I also didn't want to drain the oil. I had an assortment of rubber o-rings from Harbor Freight and one fit snuggly around the drain plug body and between the surround of the oil pan. 180 Piece Viton O-Ring Kit (harborfreight.com)

danby

Am I understanding correctly that you just pressed this into the small gap between the bolt and the pan without touching the bolt at all? This sounds intriguing

yebokmj

Yes, you are understanding me correctly. I just pressed an o-ring in there and I've not had a leak since.

danby

That's great, thanks for the idea. My leak is extremely slow so I decided not to mess with it until the next change, but I'll definitely do this in the meantime.

Incidentally, I bought an LN magnetic plug thinking that may also help. Based on your experience it seems like it may have the same issues. Have you found anything that helps with it or do you just default to this o-ring now?

TMc993

How did you get a proper torque on the plug with the o-ring in place? Seems that over time, engine heat cycles would cause the o-ring to deteriorate and leave you with a loosely fitted drain plug.

yebokmj

The LN Engineering magnetic drain plug is notorious for leaking. I actually stopped using it and went back to stock. I just installed a used engine so I threw it back in to inspect at next service. I'm unsure if I will run it next service, but if I do I'll run the o-ring again.

yebokmj

TMc993, the added o-ring has no effect on the torquing of the drain plug as it's installed after the drain plug is installed. You just press it in with no your hand in the gap between the drain plug and pan.