Oil leak in my 987.2 Cayman?

Hi all - I'm loving my 987.2 (bought in Feb) and have been doing some basic maintenance. I finally got around to changing my manual transmission fluid yesterday. While I was under the car, I noticed evidence of some oil dripping inside the cover plate (whatever you call it) - near the yellow arrows in the picture below (not my car, thx Pelicanparts for the photo). When I got underneath, I also saw a coating of oil on the plastic parts here see smaller picture below. This is a view straight up from the driver's side. The hex bolt at the bottom left is the fill for the transmission fluid. I sometimes get some white smoke at startup that quickly clears up. Not sure if I need a new AOS, if this is normal oil seepage (wishful thinking on my part?) or if this may be a more serious issue. I wiped up the oil I could reach and will look at it again after some more driving to see how active the leak might be. Close up shot here: Any thoughts of what this might be?

Several things: There is no model called "base" - you own a Boxster 987.2 2.7L. Porsche never named any model "base".. You didn't mention how many miles or what year your 987.2 is. The AOS is less troublesome on the 9A1 engines, and normally doesn't require replacement before 100k miles or so. There is no such thing as "normal oil seepage" - any seepage is abnormal. There could be "acceptable oil seepage" (although my standard for that is no oil seepage..) It will be interesting in what you see after some time, if there is fresh oil leaking. This looks like oil vapor deposits. Trick to diagnose, unfortunately, your photos are so close up I'd have to take them out to my car and get it up high enough to crawl underneath to try to get the same view you showed in the photo.

Thanks, Don I should have mentioned, this is a Cayman , 2.9L engine, just hit 85K miles (about 1,000 more than when I got it in mid February). I've seen the term 'base' in most parts websites when I'm selecting which car I'm buying for, but I do see my owner's manual specifies " Cayman " or " Cayman S " - no "base". I stand corrected. I'll see what I can find out about oil vapor deposits, and will talk to my Porsche mechanic next time I have the vehicle in for service. In the meantime, I'd love to hear any other thoughts on what I may be dealing with.

Ive always called mine a base - not an S , oh well .... This looks a bit more than vapor , but with smoke at start up ( how long does it last) it could be AOS . You wiped it clean so see if it seeps back ( could have been a sloppy oil change) ... tough to say keep us posted

They should be called the Cayman with the standard brakes or the 5sp Cayman … that motor doesn’t have the IMS bearing so I’d guess it’s the RMS or AOS …bring it to a good indy shop… with that mileage it’s probably due for a clutch soon anyway… let us know the a91 motors are pretty good motors “base😜” or S

Make sure the clamps on the intake boots are torqued to spec (3.5 ft-lb, 5 Nm). I had seepage when I first purchased my 987.2 Cayman . Both clamps were loose, and after torquing them to spec I no longer have seepage.

At that mileage and because they aren't really expensive, I'd put a new AOS in it too. Like so many other jobs, I'm confident my second AOS replacement would be quicker and smoother but the first dance requires decent skills, there's a thread I made and took photos or PM me and I can tell you about the job. PS I do not think the AOS has caused this I think Don has the right call with the clamps but my new AOS has resulted in almost zero start up smoke.

Thanks all - I bought a new AOS and is next on my 'to do' list. I found some good posts walking through the procedure and am confident I can do the work, even it it takes me a while. I'll also check the torque on the intake boot clamps. Any advice on where to research how to do this? Sounds like something that I should do at the same time I replace the AOS . I was hoping not to have to get a new clutch just yet, but I do have a well-recommended indy mechanic here in Northern VA (Jose at Autobahn Service Inc., recommended by an old buddy with his '80s era 944) for when I need to do that work. Not sure if I hit a nerve with the 'base' vs 'no such thing as base' debate, but either way, I'm digging my 6-speed, no- IMS , standard-brakes Cayman , and am definitely learning a lot on this forum.

When you remove the upper engine cover you will see the intake boot clamps right away. They are on the top of the engine and easily accessible. Search YouTube for AOS replacement videos on the Cayman . When I did mine I followed one and got everything done in under an hour. The trickiest part is rotating it when removing and installing. The videos will show you how.

Well, I went to replace my AOS yesterday and discovered that the crankcase vent hose was cracked almost all the way through. There doesn't seem to be much oil around the crack, but I did have to go order a new one from Pelican Parts . Should get here Friday, when I'll replace both the hose and the AOS . Does anybody have experience with this? Anything else I should look out for? There are lots of articles on AOS replacement, but I have found very little about the hoses themselves.

Only the AOS vent for me… Something I’ve seen many times before and I don’t think Porsche refer cars to a base model but this is probably why it has come up a few times (many times) about base vs S model cars, Porsche refers to the car as a base model on the window sticker and then the list of option makes it what model it is… in this case a C4S…. I’m guessing this is why it started

Interesting - so in this case an S was referred to by the Monroney ( https://en.wikipedia.org/wiki/Monroney_sticker ) as a "Base" model. The Monroney is a US only thing - required to sell a new car in the US, and only removable by the owner (supposedly - but lots of dealers remove them during delivery prep..) I stand partly corrected - I say partly since I'm sure even in the US, Porsche doesn't refer to it as a 911 Base C4S.. Is there even such a thing as a 911 "Base" model that can be purchased? If so - does it say "Base" in nice script lettering across the back?

Just a quick update - I got the crankcase vent hose from Pelican Parts and installed it and the AOS today. Wow, that AOS was a bear to get unseated - must have taken me 20 minutes of rocking it, it just did not want to come out. It was like an old bar puzzle to get it out - and the new one in. Turn upside down, spin sideways, pat your head twice. Youtube videos were helpful but theirs seemed much easier than mine to come out. Went for a nice drive - all seems to work fine. I'll keep an eye on the level of smoke at startup.

It’s normal for a little smoke at startup.. sometimes it does and other times not much at all..

I would think you have corrected your vacuum leaks now. As for any carbon build up. you have port injectors not direct injection. Port injection does not have intake valve carbon build up. I would think your engine startup smoke should be minimal now.