We have a 2000 Subaru Outback, new to us. Over the last couple months, we've noticed a "clunking" noise when the car is turned on. We haven't experienced any problems with the car actually starting or running other than the disconcerting noise. I'm not sure if it's a noise that comes with age or a sign of bad things to come and wanted some insight (sadly, I know nothing about cars).

For the first time today, the normal clunk was followed soon after by a series of clunks in a row and then business as usual. Could this have anything to do with the very cold outdoor temp? Something much worse? At our wit's end!

Automatic or stick?

automatic

I was thinking it could be 2 things.

 

1. Your automatic tranny gaining line pressure

 

2. The vents in your vehicle moving due to the vacum building up and switching them over.

 

 

Anybody have any other ideas?

This happened to me for a while, I was really woried about it being something expensive. Then i realised i was stupid and I had left the ball in my hitch and it didn't fit perfectly. For some reason it only happened when I started and stoped the car.

He said it is when he "starts" the car...not accelerating.

I don't know anything about Subaru's, but I've been reading up on here, and it seems like he might be describing the piston whip or piston lash condition...

 

But I don't know shhh.

Chuck

Does it do it every time you start it or just sometimes?

 

If it does it all the time, did it ever just do it sometimes before progressing into a worse condition?

 

Do you ever start it smoothly, drive somewhere, shut car off for 10 minutes or so, then have it clunk upon restart?

 

This is very interesting.

I don't think the clunk would be the piston slap. Where does the sound come from? Inside the car or the engine compartment?