[reficuliu]

So I've already had the left exhaust replaced before due to a rattle coming from the flap. However, it recently started up again. At start up, I hear a rattle after about 5 seconds of starting the engine, and it's every time i start the engine. I took a flash light to observe the flap, and I noticed that it starts open, then begins to close, VERY VERY SLOWLY (about 5-8 seconds to fully close). The rattle is being caused by the slow closing of the flap and vibration of it. Thus, the rattle stops once the flap is completely shut. Anyone have any experience with this issue? Any solutions?

Notes:
-The dealer took a look at it, and said the flap was fine, but there was something wrong with the tubes that link to the vacuum. (Tubes apparently aren't covered under my Platinum All Comprehensive Extended Warranty.. . ..)
-Would it be a leaking tube, or the actuator, or the valve itself just being stuck.
-Is the exhaust flap supposed to be open when the engine is off? I looked into the exhaust after turning off the engine and noticed it was open.
-Would the Golf Tee Mod fix this issue?

[JamesM3M5]

Golf Tee mod will leave the flap open all the time. It will probably still rattle.

You will have to check the hoses for any leaks, etc. Also could be a weak vacuum pump or a vacuum leak anywhere else in the system that causes the pump to take a long time to pull down. The same pump also supplies the vacuum brake booster and turbo controls.

[PR3CI5N]

+1 Just golf tee mod it and call it a day! Or get a JB4 and rock CAN flap open.

[reficuliu]

Originally Posted by JamesM3M5

Golf Tee mod will leave the flap open all the time. It will probably still rattle.

You will have to check the hoses for any leaks, etc. Also could be a weak vacuum pump or a vacuum leak anywhere else in the system that causes the pump to take a long time to pull down. The same pump also supplies the vacuum brake booster and turbo controls.

Thanks for the input!

I will probably try the Golf Tee Mod to see if it still rattles while completely open.
Currently it seems to only rattle in the process of closing.

The dealer was charging 100+ just on the diagnostic. My question is, is it ok to just leave the rattle as is? Or is this a must-fix situation where the vacuum pump would affect something else?

If the only part affected is the flap (which it seems that most people state is there strictly for noise level purposes) is it even worth it throwing down all this money just to fix this flap?

[blacknbean]

i had the rattle, did the golf tee (although i unplugged it from the trunk) and it doesnt rattle and exhaust sounds a lot better.

[reficuliu]

Originally Posted by blacknbean

i had the rattle, did the golf tee (although i unplugged it from the trunk) and it doesnt rattle and exhaust sounds a lot better.

I was considering this, but i dunno if i want a hidden code thrown.

I will try one of these tonight.

Thanks for all the input!

[Streetsweeper360]

Fold the line by the flapper with 2 zip
Ties .

[bmwti]

mine rattled pretty bad.

golf tee mod fixed the problem instantly.

[Brey335i]

Golf tee mod fixes it in 9/10 instances

[reficuliu]

Thanks guys for all the input.
So I went ahead to Golf Tee Mod, I just did the trunk unplug.
And Voila the rattle is gone.

It seems as if many ppl here have experienced the same rattle, and this is the solution?
Is there anyone with experience trying to fix the rattle correctly and properly?
It almost makes it seem as if BMW created more trouble than good by implementing the exhaust flap.