[cas951]

I've owned my Boxster for just over 18 months now and I've observed a lot of the issues that members have faced. This being one of them. I noticed this issue after I did my first oil change. Before the oil change this did not occur. At first it was the smell that made me notice. At a stop I could see smoke coming from the right side. It was not continous but there every so often. If I drove the car hard the smoke is more noticeable specially when I park the car. I jacked up the car and saw wet spots coming from my valve cover. I tightened up the valve cover bolts but this did not fix the issue. At this point I didn't want to replace the gasket just yet so I let it go. I drove it like that for a few months since the car is not driven daily and just lived with that leak. It wasn't noticeable on the floor. After few months I started to notice smoke from my exhaust when I firts started up in the morning, engine started to run rough when idling when cold. After researching the symptom the problem pointed to the AOS. I called several shops to see what they charge and man what a shocker. Due to my car being a Tip a private shop wanted to charge 15 hrs of labor @ $115.00 per hr since the Engine has to be dropped. The dealer wanted $900.00. From speaking to the Service Manager he said AOS failure is due to oil overfill. This really made me think. Reading the Forums owners have used 0W-40 and used anywhere from 9.0 to 9.5 quarts of oil. Most used 9.5 quarts. Owners manual recommends I think it was 15W-40 and 10W-40 as alternate depending on year.

I did the repair myself. Took about 2 hrs but most of that time was figuring out the best way to do this. Specially that hose clamp below. After replacing the AOS I filled the oil level with only 8.5 quarts. Previous oil change I filled with 9.2 qts. Ever since I did this the smoke from tailpipe disappeared and the car ran perfect. The oil leak from the side vent dissappeared.

I think part of our problem is we read too much about our cars over the internet. Yes we find a lof of imformation and most are good. But in this case I think we need to relook at this because this small issue (Oil Capacity & Proper Oil) could be the cause of our bigger issues. Lets start reading more into the Owners manual. This publication was made referencing how Porsche engineered and developed/tested these cars (Earlier cars) specially the type and Wt of oil to use. I personally believe this is contributing to the cause of the RMS and after reading the M96 engine review in Excellence this is contributing to IMS failure as well. It all starts with Engine oil overfull and we maybe using oil that is too thin. The combination of Oil overfill, oil being too thin creates too much internal pressure inside the engine that the AOS cannot maintain. Too much pressure has to be released somewhere so it start to leak to the weakest point of the seals on the engine i.e. RMS, valve cover etc. M96 engine review in Excellence showed that every engine that had IMS failure had oil in the IMS sealed bearing. Engine that did not have IMS failure had no oil in the sealed bearing. This is just my opinion so please do not flame.

Sorry for such a long post.