[Mk2] [Turbo] Fast Idle and High Pitched Whistle Since Flat Battery

[Clarkey1990]

Returned from a week away to find the battery flat, no problem I thought, put it on charge overnight, dropped it back in and away I went. At first the idle speed was around 2000 when cold and 1800 when warm, I thought it might settle down after a few days once the ECU has relearned the car.

That's about 2 weeks ago and the idle speed is still the same and there's now a more prominent high pitched whistle when idling and under little or no throttle, the whistle disappears when you engage more than 1/4 throttle. Should be said that the whistle remains when the car is coasting off throttle in gear too.

Can't pinpoint exactly where the whistle is coming from, any ideas?

Cheers

Sam

[Chumbaside]

Sounds like it could be a vacuum leak or potentially the idle control valve.

Either way, if you're near Sutton Coldfield this weekend I'm happy to take a look to see if I can help at all

[Zeppozen]

did you ever fnd out what it was ?

I have high idle, but i think the whistle is the alternator.