Chirping sound

[Wangler]

I wonder if there’s anyone out there who can help with identifying quite a loud chirping sound from my S3 engine.

It sometimes happens when the car has been standing for few weeks. It goes after a few minutes of driving, but I would love to know the cause of it. I just cannot locate its source, even with a hose as a listening aid.

It’s not from the alternator as I’ve disconnected it and the noise is still there. I’m pretty certain it’s not the water pump either. I’m hoping it’s not internal but I’m running out of ideas.

If anyone can hazard an educated guess I would be very grateful. I can send a recording to a private email but unfortunately the file isn’t one that is accepted on this forum.

[lancialulu]

Manifold rubber or other gasket. Squirt so WD40 around.

[Wangler]

Tim, you are a star. Thank you so much.

I squirted some WD40 around the manifold and couldn't really see anything, but when I was wiping it off I covered the tops of the carbs/manifold with a large cloth and the sound moderated significantly. I checked the tightness of the manifold nuts (meant to be self locking) and they were all loose. As soon as I did the first one up the noise almost vanished, then when I did the others it was completely gone. The tickover also improved. I guess my chirping description was a pretty appropriate one - air being forced through a very small orifice.

I put on a new Pirelli manifold mount last year so the rubbers should be perfect, but I was most surprised that the nuts had loosened. I guess the rubber gaskets compress a little, so it's probably standard practice to tighten them after a couple of hundred miles.

Anyway, many thanks again, I was worried that it might be something rather expensive.