[halfmonkey]

So I took my car in for routine service as my iDrive said I was due for service and will in there mentioned to my SA that upon cold starts, I hear the left exhaust pipe rattling for 5 seconds or so and then it goes away. After leaving the car with them, they tell me that it's basically a flap inside the exhaust that is suppose to open and close based on driving demands. The harder you drive and so the more exhaust gases, the more the flap will open. In any case he tells me that's he's seen a few cars with this issue and basically said it's due to a vacuum leak or something. He said that after a little bit of time upon cold start the rattle goes away and it's not like it robs power or anything like that. It's more of an annoyance.

So we talk about the fix and apparently the fix is for BMW to cut (yes, cut) off the left exhaust pipe and replace it with a new section which will be held together with clamps. That sounded a little odd to me so I asked a little more about it and he said the exhaust is actually a one piece unit and instead of BMW replacing the whole unit, they're only fixing the actually part that it causing the problem. Sounds like BMW is cutting costs.

So I was hoping to ask you fellow owners if anybody has had this fix done and if so, can you provide me some feedback. I'm sure the rattle will go away but have you had any related issues since the fix. I guess I'm concerned that they're going to cut off the bad section and replace it and tie the exhaust system all together with clamps.

[AoS810]

im no expert on 335's.. but that sounds like the same flap that gets disabled when you do the golf tee mod? I apologize if I'm completely wrong. If I'm right, then I guess you could just.. do the golf tee mod and that'll basically prevent the flap from moving ever again..?

[samchoi604]

Originally Posted by AoS810

im no expert on 335's.. but that sounds like the same flap that gets disabled when you do the golf tee mod? I apologize if I'm completely wrong. If I'm right, then I guess you could just.. do the golf tee mod and that'll basically prevent the flap from moving ever again..?

+1

Just do this:
http://www.e90post.com/forums/showthread.php?t=80661

[aohus]

To OP,

I had the same exact issue. They did end up cutting off half the muffler and replaced the left muffler.

Kinda teed as I wanted them to replace the whole unit but it was after the fact. The reasoning they gave you is the same thing they told me.

I was getting rattling noise any time I revved.

Now, I am at the shop again because DS mode is failing, but the rattling noise is fixed.

BMW's are unreliable as fuck all lol.

[halfmonkey]

Originally Posted by aohus

To OP,

I had the same exact issue. They did end up cutting off half the muffler and replaced the left muffler.

Kinda teed as I wanted them to replace the whole unit but it was after the fact. The reasoning they gave you is the same thing they told me.

I was getting rattling noise any time I revved.

Now, I am at the shop again because DS mode is failing, but the rattling noise is fixed.

BMW's are unreliable as fuck all lol.

Do you know if they actually just used clamps to join the exhaust system back together? I'm really hesitant to go through with this cheap fix.

[Nex054]

OP, did you go through with the fix? What were the results? I seem to be having the same problem as you, but would rather not have my exhaust system cut up if the "golf tee" mod achieves the same results.

[reaper335]

yes they use clamps.. it's the same thing you would have to do if you got an aftermarket exhaust. dinan exhaust is the same way. if bmw had to tell you about a problem you didn't even notice then don't get it done. and idk if the golf tee mod would fix the rattle or not. worth a shot though

[Edward]

I hate the idea of a cut and clamped exhaust. If the factory went through the trouble of producing perfect seamless one piece piping with no hacks or clamps where they aren't needed, I don't want some guy at a dealership doing it to my car. Mine rattled BADLY so I plugged my vacuum line with a golf tee and now the car sounds even better and there is no rattle whatsoever.

The build quality of that valve system is a wretched failure. Pathetic doesn't even begin to describe it. I'd say that pretty much 90% of all 335i's I drive by on the road have that rattle when they accelerate from a stop. Why have I never once heard a rattle on the droves of F430s and 458s you see on the roads? Those cars create so much more back pressure than a wimpy i6 does. There are a lot of other cars on the road that have a valve and you never seem to hear them chattering away at stop lights.

[ac09lude]

i have this some rattle from my left exhaust tip and i have the golf tee mod!! what should i do?

[scarzie]

The biggest PITA for me about this issue is that sometimes when I go to sit down in my car when its off I can hear it rattle as I sit down, it drives me crazy

[halfmonkey]

Originally Posted by Edward

I hate the idea of a cut and clamped exhaust. If the factory went through the trouble of producing perfect seamless one piece piping with no hacks or clamps where they aren't needed, I don't want some guy at a dealership doing it to my car. Mine rattled BADLY so I plugged my vacuum line with a golf tee and now the car sounds even better and there is no rattle whatsoever.

The build quality of that valve system is a wretched failure. Pathetic doesn't even begin to describe it. I'd say that pretty much 90% of all 335i's I drive by on the road have that rattle when they accelerate from a stop. Why have I never once heard a rattle on the droves of F430s and 458s you see on the roads? Those cars create so much more back pressure than a wimpy i6 does. There are a lot of other cars on the road that have a valve and you never seem to hear them chattering away at stop lights.

I am scheduled to bring my car in next tuesday for the fix. I've been kinda caught up with other things so I wasn't able to have it done earlier but it also gave me a chance to think about the "fix."

IMO, this is a "cheap fix" that BMW is doing. The right thing for BMW to do is replace the one piece unit with another one piece unit but of course, they're cost cutting and that's why their remedy is to cut off the ailing piece and replace it. Will it "fix" the problem? Supposedly, it will. Is it the proper way to fix it? IMO, no. Will I hold BMW accountable if something wrong arises due to this "cheap fix?" Absolutely.

The thing for me was that at first, I just thought it was rattling when I started the car cold and then once I got going, I thought the rattling went away. Then the other day, I was driving and happened to drive where I heard some rattling reverberating back to me from the wall or something. Normally, I drive with my windows open, listening to my music so it was just happen chance that I heard the rattling. After that, I turned off the music and stuck my head out of the window (of course in a safe area) and I could hear the rattling even in light accelartion. After that, I thought it was embarassing to be driving around in my 335i passing people on sidewalks and in parking structures and they hear my car rattling like it's about to fall apart. At that point, I decided I would fix it because I don't want my car to be rattling as I'm driving around. It's def not going to help me when I take someone on a test drive down the road when I go to sell my car.

I'm not doing the golf tee mod because it's not a fix but rather a band aid and I believe it actually stores and error code. I may be wrong about htis but I thought I've before about people doing the golf tee mod and it throwing a code.

[halfmonkey]

Originally Posted by ac09lude

i have this some rattle from my left exhaust tip and i have the golf tee mod!! what should i do?

All I can say is that I thought the rattle was onyl there when I started the car when cold but one day I heard the rattle while accelerating and that changed my mind about doing the "fix." You might want to remove the golf tee mod to hear how bad your rattle is and then go from there. My guess is that the rattle will only get worse once it starts and the rattle may be just like the hpfp fiasco in that it wasn't about IF the problem would arise but a matter of WHEN the problem would arise.

[reaper335]

we can't even order the single "one piece" unit. both mufflers are their own part #s as is the piping behind the mufflers to the cat. bmw isn't trying to cut costs by doing this.. it's just how they've been doing it. you won't even know it's cut appart when they are done with it.

[Edward]

Originally Posted by halfmonkey

I'm not doing the golf tee mod because it's not a fix but rather a band aid and I believe it actually stores and error code. I may be wrong about htis but I thought I've before about people doing the golf tee mod and it throwing a code.

It can throw a code if you unplug the thing in the trunk. If you physically plug the hose under the car, it will never throw a code. Mine rattled all the time. It rattled constantly and loudly at warmup idle rpm, and it would continue to rattle while I was driving...especially if it was going to stay closed as I coasted. It was horrendous.

Even if a clamped exhaust is rather unlikely to cause real problems, it looks awful from under the car behind it, and the replacement unit will almost be undoubtedly develop the same symptom. How many times can you replace it?

[halfmonkey]

Originally Posted by Edward

It can throw a code if you unplug the thing in the trunk. If you physically plug the hose under the car, it will never throw a code. Mine rattled all the time. It rattled constantly and loudly at warmup idle rpm, and it would continue to rattle while I was driving...especially if it was going to stay closed as I coasted. It was horrendous.

Even if a clamped exhaust is rather unlikely to cause real problems, it looks awful from under the car behind it, and the replacement unit will almost be undoubtedly develop the same symptom. How many times can you replace it?

I hope that the cut and replace "fix" will actually fix and prevent the rattling from reoccurring but if it does come back, then that's all the more reason for me to dump this car because quite frankly, I'm very surprised at how many issues I've had with this car.

Sad to say but BMW are not reliabile cars. Fun to drive but unreliability does wear on you after a while and it's sad to see that people will accept the unreliability just so they can own the propeler badge. I want to own a bmw but I want to own a reliabile bmw. (getting off my soap box now.)

[BTTGMan]

I had this done a few months ago. No big deal. For obvious reasons golf tee won't fix it. After I fixed it I did golf tee anyway. Fix was easy.

All the bitching about WELDING part of an exhaust system is ridiculous. This is no big deal. You do get a new exhaust tip too, so ore pare to polish the old one so they match. Also tell dealer to make sure tips are at identical heights.

[Sidefly]

I had the cut/replace/clamp done by my dealer because my flap was stuck open (I should have left well enough alone). Now mine is rattling like crazy. I am tempted to put a spot weld on it to hold it open. Thoughts?