What is Porsche AOS?
The AOS, or air oil separator, is a part of the PCV system on a modern Porsche sports car engine found in Boxster, Cayman, and 911 models. The AOS directly affects the engine crankcase atmosphere by applying a very small vacuum to it by the nature of its job; it should be named a vacuum-oil separator.
What is a RMS Porsche problem?
RMS problems are common on Porsche 996, 997, Boxster and Cayman models and in most cases they usually cause nothing more than a slight oil leak however, in some severe cases it can cause contamination to the clutch friction plate, resulting in poor gear selection and loss of performance.
What causes smoke at the start of a Porsche 911?
The smoke at startup can also be caused by a air oil separator (AOS) that is going bad but not completely failed yet. The M96 and M97 engines are famed for cylinder scoring – deep gauges in the cylinder liner, usually associated with a knocking noise and eventually catastrophic engine failure.
Are there any mechanical problems with my Porsche 911?
Listed below are Porsche 911 common mechanical problems with their likely resolutions. These are the most frequent 911 problems diagnosed by our repair shops over the years. An accurate diagnosis of an issue by a Porsche mechanic typically saves you time and money – see our guide to local independent Porsche repair shops that can help.
Why is the Check Engine light back on on my Porsche 911?
The fault codes will suggest faulty O2 sensors. This results in many folks replacing the front O2 sensors in the hopes of solving the problem, only to discover that within a few hundred miles the check engine light is back on. The problem is actually caused by the MAF failing and by owners blindly believing the reported engine faults.
What causes an oil leak in a Porsche 911?
A failing air oil separator (aos) is the likely cause of rear main seal failure and oil leaks, as it is in other VAG cars. Crankcase vacuum exceeds the normal range in the engine under heavy acceleration and sucks in air damaging the rear main seal.
Why is my Porsche 911 smoking on start up?
The boxer (flat plane) engine has its combustion chambers on a similar level to the crankshaft and at rest, oil can seep into them particularly if there is general engine wear – this will cause smoking on start up and is common in most 911’s – particularly early models with air-cooled engines, where the tolerances are slacker.
What kind of smoke does a Porsche 997 make?
On first start up of the day it produces a cloud a blue-ish smoke that is enough to fill my driveway and swirl onto the road. It lasts for a second or two only.
Why does my Porsche 911 have a vacuum problem?
Crankcase vacuum exceeds the normal range in the engine under heavy acceleration and sucks in air damaging the rear main seal. This is commonly seen on Audi engines as well.
A failing air oil separator (aos) is the likely cause of rear main seal failure and oil leaks, as it is in other VAG cars. Crankcase vacuum exceeds the normal range in the engine under heavy acceleration and sucks in air damaging the rear main seal.