Rough Idle
 

Hi everybody,
I recently bought a 2000 Boxster S with 68.000 km, now I'm 74.000. I soon, through the nearby garage. had a comprehensive service with new water pump, 83 C° thermostat, new fluids,.. . The car runs very smooth, I'm very satisfied. The only problem occurs after long traffic jams when heat bilds up under the engine compartment. The water temp. is very steady with the marker just after the 0 of the 80 figure. It happens that the idle start fluctuating and I need keeping revs high to prevent stall. If in altitude (2500 m) it's even worst and starting again is difficult. Everything comes back to normal when heat dissipates. It seems there is a sensor fouling when hot.
Has someone experienced something similar, any ideas on root causes.

Additionally, the convertible top operates well. Is there any specific maintenance or lubrication to keep it in perfect shape.

Thanks

Mike Delta

1.Any codes/pending codes?
2.Does the engine compartment ventilation fan operate correctly?

No error codes
The fan seems running, the fan noise is detectable . Which is its operating range?



MikeDelta

After investigation I decided cleaning the TB( not so dirty), and fully cleaned the water radiators and A/C condenser at the front in order to prevent engine compartment overheating. I hope it solve the dancing idle when engine compartment gets hot. There was a lot of dirty in between the two cooling parts.


MikeDelta

I had the same issues with my '01 Box. My mechanic ran all the tests on it and said everything looked fine with AOS and was sure that the throttle body was causing the problem. He told me to clean it and sure enough, that solved the problem. All that carbon build up was causing the rough idle. This is a fairly easy repair, although taking off the intake box was a pain in the arse. Here's the link to the repair - Porsche Boxster Starter Replacement - 986 / 987 (1997-08) - Pelican Parts Technical Article
I know it says it's for the starter replacement but the very first part shows you how to remove the throttle body.

Hints**
You don't need to take off the hose that goes to the AOS to take the throttle body off.
You'll need a torx set to take the 4 long gold colored bolts that connect to the intake tube just behind the throttle body. (See picture in link below.)
http://www.pelicanparts.com/techarticles/Boxster_Tech/83-ELEC-Starter_Replacement/images_med/Pic2.jpg
You will need to disconnect some electrical plug on the bottom of the throttle body.
That's it!

Good luck!

Hello,

i don't think it is the TB in this case. And if you says you've already checked it and it was clean there might be another problem.

At which altitude do you use the car in general?

Maybe the car is running a little bit too lean. Did you check the fuel pressure and when did you change the fuel filter last time (think a 2000 will have a separated fuel filter).

Regards, Markus

2000 Box has the fuel filter under the center of the car.

You need to pull the engine codes from the computer. If the engine runs that poorly there must be a code to go with it.