Stock Exhaust Question.

[socal318ti]

Im not sure this pertains to the after market exhaust spec but it seems that my exhaust system has developed something of a rattle when the car starts. Its only for a bit but once the car warms up it seems to go away. Im thinking it might just be a loose bracket or something. If anyone could point me in the direction to fixing it that'd be great. Thanks.

[bimmerboi318]

My first guess would be a heatsheild. I've ripped about 3 off of my car so far. Could be a few other things though, like a cat converter that has broken up inside (usually associated with low power too).

[socal318ti]

Is there any way to check to see if its the heat shield? Or could it just possibly be a bracket for the exhaust that has worked its way loose? The sound seems to be coming from the rear of the car, right around the muffler, which makes me think its just a bracket or something.

If it is the cat I'll probably just look at replacing the entire exhaust system. I've read about supersprint ones but i'd like a bit more info before i make a decision. Although I hope it isn't, I just had to replace the diff due to problems. (see my thread in the diffs section) Thanks again everyone for your help.

[bimmerboi318]

The only way really to check for a heat sheild is to get on the ground (or get your car in the air) and physically check everything over. I simply pulled them off when they started to rattle, and never had a problem after...but they are there for a reason... The one around the cat I believe is more to keep it hot so it works better. I ripped that one off as well. As far as rear brackets go, I suppose they MIGHT be able to rattle, but they are rubber hangers and are usually pretty quiet.

[socal318ti]

Yah. I think I might have to get it up in the air to take a look. It doesn't bother me to much so I guess its ok. As long as my exhaust doesn't start to emit some crazy black smoke I think im doing alright.

[Sarafil]

Yah. I think I might have to get it up in the air to take a look. It doesn't bother me to much so I guess its ok. As long as my exhaust doesn't start to emit some crazy black smoke I think im doing alright.

Did you ever look into this? I have a rattle that sounds like it is coming from the exhaust area and it happens when the car is idling. It seems to go away (or hidden) when the RPMs increase. It doesn't go away when the car warms up, either-- it still rattles when the car is idling at the drive through at the coffee shop near my work, and by then the car is fully warmed up.

Does this sound like it could be a heat shield? Could it be something else?

[cali-ti]

sarafil, easiest way to check and see if it's the heat shield is to try to move the heat shield around while the car is off and the exhaust is cool. if your arm is long enough, you can do this without raising the car. i secured mine without removing it and it was completely free from the cat, causing quite the rattles.

[Sarafil]

sarafil, easiest way to check and see if it's the heat shield is to try to move the heat shield around while the car is off and the exhaust is cool. if your arm is long enough, you can do this without raising the car. i secured mine without removing it and it was completely free from the cat, causing quite the rattles.

Thanks for the tip. I'll see if I can take a look at it this week. The rattling is driving me crazy!!!

[cali-ti]

Thanks for the tip. I'll see if I can take a look at it this week. The rattling is driving me crazy!!!

i totally understand.

to be more clear, i should say that i was able to secure the heat shield using screws into the cat itself, rather than removing the heat shield altogether. i was even thinking as an improvement, i should space the shield from the cat with some washers, but right now it's just sheet metal screwed into the cat at like four places. they can get loose over time and need to be tightened.