Pwnin O'brien

So last weekend I thoroughly cleaned by throttle body as it was pretty dirty and hadn't been cleaned in a really long time (since I owned the car). After I finished cleaning it I put it back on the car and reset the ECU and then did a pedal relearn, a throttle position relearn, and an idle air volume relearn. The car runs beautifully and idles exactly at 750rpm's.

I immediately noticed, however, when I am accelerating above 1500rpm's, I can hear (with the windows down) a loud hissing sound which gets louder the more I accelerate. The hissing sounds like a turbo spooling up.

I checked to make sure that there are no pinched hoses from the intake and everything was reinstalled perfectly. I have a K&N cold air kit on the car. I just thought this noise was normal and didn't really think too much about it, but I now worry a bit that something may be choking. Has anybody else experienced this? Does anybody have any suggestions as to what could be making this sound?

I have another un-related question for anybody who has the K&N cold air kit installed. On the bottom of the intake tube around the middle there are two hose outlet grommets. I only have one hose physically connected because I didn't have another to hook up. Is there supposed to be two hoses hooked up to it? What is the second (larger) hose for? Is this a hose used on other R50 models? I currently have the larger grommet plugged up.

Here are a couple of pics from the installation manual of what I'm talking about:







Thanks!

Pwnin O'brien

After some reading and detective work, I think I may have found the problem. I read that you should ALWAYS replace the throttle body gasket when removing the throttle body. Even the smallest hairline crack in the gasket will make a whistling noise from the throttle body.

I'll replace the gasket and let you know my findings.

Pwnin O'brien

Well I replaced the old gasket with a new one and the hissing has disappeared completely.