strange noise after turn on headkights

[aabm]

Hi everyone. I need help whit my 2000 S. When I turn on the headlights, most of times, I start wearing a tap tap tap noise in the rear engine and sometimes I get oil or battery warning lights, or both. I just shut off the car and in restart, turn de headlights on and 8 in 10 times all is ok. Sometimes I have to restart the car twice. Can someone help me whit this? Could be some error in electric system whit the headlights switch and the rear spoiler? I have no idea, the spoiler stays down.

Another problem is the engine idle. I have clean de MAF and change the air filter, but only works smooth whit the air conditioned on and from some level of ventilation. That’s strange too. Anyone can help?

Thank

[Cassiebox]

You don't happen to have an aftermarket HID/Xenon light kit in there do you? Warning lights are common w/ some of the cheaper made kits.

Otherwise, could be issue w/ light switch (common failure), ignition switch (common failure) or alternator (at 10+ yrs old w/ ?? miles, not uncommon).

As for MAF, are you getting any check engine light or error codes? Usually people have erratic idle when AC is ON... so I guess you have a good problem w/ steady idle. Might try cleaning the throttle body too. Also, was AOS (Air Oil Separator) ever replaced?

:)

[aabm]

You don't happen to have an aftermarket HID/Xenon light kit in there do you? Warning lights are common w/ some of the cheaper made kits.

Otherwise, could be issue w/ light switch (common failure), ignition switch (common failure) or alternator (at 10+ yrs old w/ ?? miles, not uncommon).

As for MAF, are you getting any check engine light or error codes? Usually people have erratic idle when AC is ON... so I guess you have a good problem w/ steady idle. Might try cleaning the throttle body too. Also, was AOS (Air Oil Separator) ever replaced?

:)

Hi Cassiebox, thanks for your answer,

The car already have original xenon lights, so maybe de light switch or the alternator, because only get the noise when I turn on the light switch. I need to replace the tensioner pulley, but I don’t believe that's the problem.

About the idle, the car do not report any errors, not at all, a friend checks with a odbc connection, but I will clean de throttle body, because, now you mentioned, the idle gets more smooth after that friend check and clean some connections in the engine near the throttle body and I will check about the AOS, but I don’t think was ever replaced.

[986fan]

I have the same thing (2001 S). A couple of times a season I'll start it up (no lights on)

-or- I'll come up to a stoplight and turn the lights on......I'll hear a loud thumping in the

rear and will have to turn the car off and restart it. It's something in the spoiler circuitry

because the next day I'll turn the car off and get out after a sub-40 mph ride and the rear

spoiler will be deployed. I retract the spoiler with the switch on the kick-panel and then

all is well for weeks/months. The spoiler seems to get out of synch with where it actually

is and is trying to retract when it already is - I think that is the thumping noise (Porsche

techs?). Then it deploys on subsequent start-ups before it is supposed to. Manually

positioning with the switch seems to fix it for a while.

That's my opinion on the (our) problem. I've posted this concern before - no responses.

[aabm]

Hi everyone

The problem with the noise, was the xenon. When I turned on the lights, sometimes, the spoiler goes up and that was the tapping noise.I change to a can-bus xenon kit and its all Ok now.

About the idle no news for now,I have to clean the throttle body first.

Thanks for all your contributions.

Edited July 18, 2011 by aabm