[CraigDseattle]

Howdy guys,

This is a follow up to earlier posts about idle adjustment, and I thought I would start a new discussion to get better visibility to this iquestion.


I have an 85 Carrera and I've gone through the idle adjustments as described in other threads here (using the jumper, yada, yada, yada). I ended up turning the air bypass/idle adjustment screw in a ways from the prior setting and that has given me a pretty stable idle just below 800 RPM with the jumper removed, and this seems to have eliminated an annoying idle bound/surging when warm, and the cold idle is okay - so that part seems good.

Here's the strange part. At this new setting, I hear a high pitch "whistle" sound when accelerating through the 2500 - 3200 RPM range, and that wasn't there before. It's hard to describe the sound but it reminds me of the sound of the turbo spooling up in my Saab.....or the sound of a hearing aide that has the volume set wrong and has feed back.

I don't hear it when cruising with the engine in that RPM range, it seems to only happen when accelerating somewhat aggressively. This makes me think it is just a whistle effect as the air is moving more rapidly through the internal passageways. But on the other hand, part of me is wondering if some electrical component is experiencing some sort of feedback or ???? that is making the sound

I can't tell where the sound is coming from since I have to be driving the car for it to occur, so I'm hoping others here had experienced this and have suggestions about what to do about it - if anything.

By the way, I am using a K&N air filter if that is important.

Thanks for the help!