Strange intermittent knocking/tapping

rawbutter
Thu, 18 Oct 2012 03:57:46 +0000
Maintenance/Repairs

I have a problem with my 2008 Saturn Astra hatchback with about 75,000 miles. So far this has stumped every mechanic I’ve taken it to. They all want to have the car for a few hours to drive it around and diagnose the problem… which I don’t want to do just yet.

Sometimes when I’m slowing down, I hear a quiet tapping/knocking coming from somewhere. The back right maybe? It’s very quick, almost like a card stuck in the spokes of a bike wheel.

The strange part, though, is that the frequency doesn’t change as I slow down. Whether I’m going 10 mph or 20, the frequency is exactly the same. Even stranger, sometimes it’s not even there.

Some other things that might be helpful: I have a manual. Pushing in the clutch doesn’t change the sound when it’s there. Neither does hitting the brakes. I did have a blowout on the highway about six months ago (the back right tire…which is why I first thought that’s where the sound was coming from), but the sound has only appeared in the last few weeks.

3 posts - 3 participants