Cayman 2.7 rev needle wiggle on idle???

[Byakkonick]

Hi everyone,

I was wondering if anyone can help me and give me some advice? I own a 2007 Cayman 2.7 and for the last month I have noticed a wiggle with my rev counter on idle. It fluctuates +/- 50 RPM's. The engine note doesn't really change though, perhaps a very very slight hunt. When I drive the car and hold the speed steady at a certain speed, eg 40 mph, I can notice the rev needle still wiggling. This is when the air con is off and on, so it isn't anything to do with that kicking in.

The oil level is spot on, so is the coolent, and the car was serviced 3 months ago by an independent Porsche dealer. The car has only covered 27 000 miles.

I am going to fill the car up with Shell Vpower fuel and add some Redex injector cleaner to see if this helps. I normally use standard unleaded fuel.

Any help would be greatly appreciated.

Nick

[Byakkonick]

Thank you for your replies. Very informative! I think it could be something to do with the MAS because a few months ago I noticed that my air filter had come detached from the housing intake pipe. I replaced the filter and noticed dirt and dust around this intake pipe. So it is very possible that dirt has got onto the MAS.

I think my first action will be to access the MAS and clean it? Is the MAS also called a lambda sensor?

Thanks,

Nick