Help Diagnosing "Clunking/Rattling" Sound

[Subaru_Nation555]

Recently the car has developed a kind of "clunking/rattling" sound when idling which leads me to believe it is something knocking around the engine bay. I checked to make sure there was no loose heat shielding and everything seemed tight. I also checked the oil level which was fine. The car runs well and doesn't seem to make any unusual sounds above idle. Any thoughts on what else I should look for? I just hope it's not something internal.

Here are two videos so you can hear the sound in question:

http://www.youtube.com/watch?v=QfAohIoYNY8
http://www.youtube.com/watch?v=Yxq-WI6jMfw
(Did anybody notice the drop fall at around 10 seconds? See the pictures below.)

Something else of note-last month I had the radiator and several coolant hoses replaced. I checked the coolant level this morning and most of the reserve tank was depleted from when I checked it last week. I can't for the life of me find another leak. Do you think it could be bad head gaskets?

Thanks for your time guys.

[crust productions.com]

Not sure? Maybe valve train noise ? Try a seafoam treatment ?
Its rhythmic so Id rule out any belt or bearing issues .

[Lunatech]

You made sure that the balancer pulley bolt was good and tight? Although the times I've had issues with it it made noise on deceleration and IIRC not at idle.

Sound a little like a flex plate issue, but I would think you would be hearing it when you engage the transmission and at shift.

What it really sounds like to me is impossible. My dodge had an air pump as part of the smog equipment, it made a very similar sound when it failed.

FWIW, good luck

[Subaru_Nation555]

Sound a little like a flex plate issue, but I would think you would be hearing it when you engage the transmission and at shift.

Good thought, the tranny did get some abuse during a recent snow storm.

It makes the same noise in "D" or "N" when at a stop. Wouldn't the flex plate be engaged and thus not "clattering" if the car was in gear and the torque converter picking up the slack?

[Lunatech]

With a load on it, such as driving it could take up any slack it may have. It's really tough saying with any certainty.

[Subaru_Nation555]

Not sure if this is at all related but there seems to be coolant leaking from around the oil pan (drivers side):

(Sorry for the large pics but I wanted to show the detail)

[Lunatech]

Hmm....perhaps you have a water pump issue?

[Legacy777]

Try removing the accessory belts to confirm it's not the p-steering pump or alternator.

May be a water pump

[Subaru_Nation555]

Yeah, water pump is a likely candidate. The sound also seems to be emanating from that area but it is hard to tell. What is a ballpark estimate on a Ej22T water pump job do you think (my mechanics labor rate is ~$80/hour)? The timing belt is also due, man cars are expensive!

[ChickN]

do it yourself....i would look thru ur inspection hole on the tranny...ive had a fexplate break and its poo poo!!! stick a screw driver tru the hole and try to move your flexpate around...no movement, probly somethin else!

[RJ93SS]

ive had a problem like this too. Check to see if your little rubber black cover is still on the top passenger side of your bellhousing. You should not be able to see the flywheel. Sometimes the covers break and can get caught down there. Have a look.

[Subaru_Nation555]

Well I got the timing belt and water replaced a couple of weeks ago and the noise is gone. I'm sure glad it wasn't the flex plate but thanks for the comments guys, I appreciate it.

[ChickN]

well thats good.....was the timing belt pretty straight forward???...i gotta do mine pretty soon!

[Subaru_Nation555]

well thats good.....was the timing belt pretty straight forward???...i gotta do mine pretty soon!

I wish I could say I did it myself. It would have been immensely satisfying, not to mention much cheaper! I think I would tried if I had more time and someone to walk me through it.

[kimokalihi]

well thats good.....was the timing belt pretty straight forward???...i gotta do mine pretty soon!

It's pretty easy. I did it when I first got my first legacy and the belt snapped. All I had was a haynes book and some handtools. First time working on the car too.

Just make sure you find a small pin to put in the timing belt tensioner before you remove the belt to keep it compressed. Otherwise you'll have to stick it in a vice and SLOWLY (a fraction of a turn at a time) compress it again and insert the pin to get the belt back on.

Also it's a good idea to replace the idlers while doing the timing belt job and some say the water pump as well. Definately check them for any kind of play or noise and replace if it's present. You can buy timing belt kits on ebay for pretty cheap which is what I did.

[ChickN]

sounds easy enough....