Weird Rattle

[ponner1us]

I have an '08 Forester(PZEV) that I just got a few weeks ago, it has about 19,500 miles. It has a weird rattle when running at idle, it almost sounds like that noise you get when you turn the car off and the engine is "cooling off." I had it checked by the dealer who said it was "normal." He also said something about exhaust baffles and the catalytic converter causing the noise, but again, "the noise is just normal for Subarus." I'm wondering if the noise is related to the exhaust shields (which I can have removed), is related to the PZEV, or is something more serious that I should be concerned about?

Even if the noise is "normal," it annoys and concerns me.

[porcupine73]

It seems kind of new to have the heat shields ratting already, but yes Subaru heat shields do like to rattle. Sometimes a lot. And in many different places. It took me quite some time to stop all those annoying rattles on my used soobs. In some areas I put a hose clamp over the shield to stop the rattling. In some areas over the exhaust they were rusted out of the bolt holes, etc. I think a person could make nearly $100 selling off the yards of heat shields as scrap.

[ponner1us]

I'm thinking of getting under there with an oven glove and seeing if holding the exhaust shield where I think it's coming from gets rid of the noise. Good idea or too hot for an oven glove?

[nickb21]

Might be okay with an oven glove on a cold start, but they get very hot very quick. Maybe double up and soak them in water. I think the two most likely places for the rattle are the Y-pipe and the shields over the cat(s).

 

If the dealer isn't too far away, maybe stop by and have them fire up another Forester they have in the lot to see if it rattles too. I had one of my local dealers replace my entire Y-pipe under warranty because of the rattling. Of course exhaust/hose clamps work well too if you'd rather save some time and frustration.

[Rooster2]

Yes an oven glove, or even just car work gloves will work just fine. Also, handy to take a small hammer with you under the car, and tap around on the exhaust system and listen for any rattly noises. I have hammered in bolts (as a wedge) on loose muffler shrouds to keep them from rattling.

[porcupine73]

Yes that's how I found some of my rattles was just with work gloves on going under there up on four ramps and feeling around, carefully of course. Some of them I knew they were heat shield rattles but I couldn't pinpoint the source even laying there looking at them until I started feeling around to see which ones were doing it. Not all the rattles happen at idle; some happen only in a certain rpm range.

 

It was frustrating at first because I would fix a few loose heat shields and then the rattle would still be there, but it was just because there were still more that were loose.