X6 Exhaust releases smoke only on driver's side

[al2011x6]

I noticed the smoke was coming out only out of the driver's side exhaust on my new X6 and when I took it to BMW they told me the passenger side has a valve that only opens the pipe when the car is going up hills or under high acceleration. He also showed me if you press this metal stick under the exhaust smoke starts coming out and the sound is really nice. So here are my questions. Did anyone notice their x6 has smoke coming out only on the driver's side? And second has anyone tried to to manually put a metal clamp on the left side so it is always open. I want to do this so the smoke comes out evenly and I did notice a better sound, however I am afraid of damaging something. Thoughts

[watoowatoo]

Originally Posted by al2011x6

I noticed the smoke was coming out only out of the driver's side exhaust on my new X6 and when I took it to BMW they told me the passenger side has a valve that only opens the pipe when the car is going up hills or under high acceleration. He also showed me if you press this metal stick under the exhaust smoke starts coming out and the sound is really nice. So here are my questions. Did anyone notice their x6 has smoke coming out only on the driver's side? And second has anyone tried to to manually put a metal clamp on the left side so it is always open. I want to do this so the smoke comes out evenly and I did notice a better sound, however I am afraid of damaging something. Thoughts

Where is the metal stick under exhaust did he press?

And to answer your question, search "golf tee mod". It doesn't harm turbo engine.

[RyuHayabusa]

I had this issue with the 335xi, I'm assuming yours is the 35i, which shares the same engine, there isn't anything you can do about it as it's the way BMW designed it. Both exhausts aren't utilized unless you are WOT, I remember reading about people who modified their electronics to use both pipes, but I never did that.

[al2011x6]

The metal stick is right next to the valve on the left side. this is for the X6. I don't know about other bmws. You can just push it in and the valve opens. But as soon as you let go it closes back up. I read something about using zip ties to tie up the black hose that is connected to the valve. I don't know and I am not sure on which method to use. I just would like to have the exhaust opened and not cause any damage to the car.

[scottjays]

Originally Posted by al2011x6

I noticed the smoke was coming out only out of the driver's side exhaust on my new X6 and when I took it to BMW they told me the passenger side has a valve that only opens the pipe when the car is going up hills or under high acceleration. He also showed me if you press this metal stick under the exhaust smoke starts coming out and the sound is really nice. So here are my questions. Did anyone notice their x6 has smoke coming out only on the driver's side? And second has anyone tried to to manually put a metal clamp on the left side so it is always open. I want to do this so the smoke comes out evenly and I did notice a better sound, however I am afraid of damaging something. Thoughts

any chance you could take a pic of the metal stick? can't seem to find it.
thanks

[dmlgc]

if this is 35i ( always helps to know) then this is correct behavior , it was designed that way. The "metal stick" is actually connected to the flap that prevents smoke going out passenger side exhaust. Yes you can mod it so both are open ( search forum it's here somewhere).

[al2011x6]

Originally Posted by scottjays

any chance you could take a pic of the metal stick? can't seem to find it.
thanks

Hey Scott,
I don't think you have it in your car. I have a 35i. I believe that on the 50i smoke comes out of both exhaust at all times. Please verify this and if you still need that picture I will post it.

[al2011x6]

Originally Posted by dmlgc

if this is 35i ( always helps to know) then this is correct behavior , it was designed that way. The "metal stick" is actually connected to the flap that prevents smoke going out passenger side exhaust. Yes you can mod it so both are open ( search forum it's here somewhere).

I do have a 35i and BMW confirmed what you said about being designed that way. I can't find how to mod it anywhere in the forum. If you find it please post the link here. I am thinking of using a metal hook. One side will connect to the metal stick and the other will go to another area right next to it under the exhaust. I noticed if I do this it will push the stick in and the exhaust will stay opened at all times. I am just afraid of doing that and causing damage to something in the car. If BMW designed to stay close don't you think I should keep it closed? I still don't quite understand the reason why this exhaust side has to stay close. It just sounds great when it is opened.

[dmlgc]

Originally Posted by al2011x6

I do have a 35i and BMW confirmed what you said about being designed that way. I can't find how to mod it anywhere in the forum. If you find it please post the link here. I am thinking of using a metal hook. One side will connect to the metal stick and the other will go to another area right next to it under the exhaust. I noticed if I do this it will push the stick in and the exhaust will stay opened at all times. I am just afraid of doing that and causing damage to something in the car. If BMW designed to stay close don't you think I should keep it closed? I still don't quite understand the reason why this exhaust side has to stay close. It just sounds great when it is opened.

here you go.
http://www.xbimmers.com/forums/showthread.php?t=341087

[watoowatoo]

The valve for the driver's side is always open. I used a zip tie to close the vacuum pipe on passenger side to see the difference. Now the zip tie is removed cause I didn't feel much changed. Now I think maybe the tie didn't hold the valve open at all.

I definitely like to see a picture of the metal part you are talking about as I don't seem to find it myself.

[dmlgc]

Originally Posted by watoowatoo

The valve for the driver's side is always open. I used a zip tie to close the vacuum pipe on passenger side to see the difference. Now the zip tie is removed cause I didn't feel much changed. Now I think maybe the tie didn't hold the valve open at all.

I definitely like to see a picture of the metal part you are talking about as I don't seem to find it myself.

You should look at the link above and try the golf tee method as it seems to have worked for folks.

[al2011x6]

Here are the pics of the "metal stick" I have been talking about.
The first pic is from the metal stick all the way up(exhaust is closed)
The second one is me pushing it in with my finger(exhaust opens)
The third one is a quick experiment of mine. Instead of disconnecting the hose as mentioned before to do the mod I just used a zip tie to hold the metal stick in. Later I will find a metal hook to take the place of the zip tie. I went for a quick drive and the car definitely had that a much nicer rumble sound coming out of the exhaust. It's weird how the side BMW closes is the one that makes the rumbling sound. This is a very harmless mod, so you can just cut the zip tie if you don't like it. I will continue to monitor the car.

[al2011x6]

I am sorry guys. This was the first time i posted pics here and was not aware of the order the pics were uploaded. So my description was wrong. It's actually the opposite. The first pic was the zip tie, second is still me pressing the stick in and the third is the stick all the way up.

[watoowatoo]

Thanks for the pictures, I am going to give it a try

[REInvestor]

Originally Posted by watoowatoo

Thanks for the pictures, I am going to give it a try

Is this exhaust problem only for the 35i?

[watoowatoo]

Originally Posted by REInvestor

Is this exhaust problem only for the 35i?

I wouldn't call it a "problem". But yes only 35i has this valve to lower the exhaust sound bellow certain rpm. 50i doesn't have it so you enjoy the v8 growl all the time!

[LANDLORD]

There is a certain amount of back pressure that is designed into any factory exhaust system. It helps with bottom end torque and gas mileage. Factory exhaust systems are calibrated to work within the engine design and specifications.

There is a reason for these exhaust valves, the M has two of them. Yes you can defeat them and yes you can replace the exhaust system. It may or may not affect the engine calibration. Only the design/test engineers know for sure.

[looch57]

Well I had been researching this topic all day and came upon this one. I tried the zip tie and it worked for about 9 miles. The sound was significantly louder and I believe I even heard the Turbo more but I noticed the zip tie broke, maybe because of the heat so i purchased stainless steel zip ties, maybe that'll do the trick. I'll let everyone know how it goes. BTW my post can be found here

http://www.xbimmers.com/forums/showthread.php?t=463974

[MYX6]

The vacuum valve is made to cover the noise restrictions. From start till about 3000rpm. it is closed to make the car more quiet in the city . After 3000rpm. when opens is taking the burn gases more easy because the right side of the rear silencer is more ""open"" there are less silencer moduls (mostly when drive out of the city).
So it is the first, most fast,most cheap ""tunning"" you can do. Cause no any problems, even make the work of the turbo easyer. Just the sound is a bit bigger but much more NICE.
P.S. Where are thise valvs to HAMANN,SUPERSPRINT..........

[Henry1515]

Originally Posted by LANDLORD

There is a certain amount of back pressure that is designed into any factory exhaust system. It helps with bottom end torque and gas mileage. Factory exhaust systems are calibrated to work within the engine design and specifications.

There is a reason for these exhaust valves, the M has two of them. Yes you can defeat them and yes you can replace the exhaust system. It may or may not affect the engine calibration. Only the design/test engineers know for sure.

But some one said for turbo engines, there is no back pressure in the exhaust. Only the NA engine has the build up back pressure in the exhaust.
For my X6 35i, the valve was removed and there is where I realized the low end torque was "lost" and the gas mileage has a huge increased.

[MYX6]

Look for the torque"lost" somewhere else. As difficult the gases go out(because of silencers and cats.) as bigger is the back presure, as harder is the work of turbo and the power loses are bigger. Thats why the sports cars are noisy using FREEFLOW EXHAUST. One of the reasons HAMANN exhaust is for export onely(of EU) is the hi level of noise.
P.S. If you fill your exhaust with potatos the torque must grow following your logic

[SKY_BIMMERS]

I noticed that too when i bought my car and i went to ask bmw if i had eny problem they told me exactly that!