335i Exhaust Vacuum line noise

akerns429 · 05-11-2015, 09:46 PM

Hey guys,

So I recently had my performance exhaust installed on my car. Since there isn't a flap in the muffler that the vacuum line connects to (like the stock mufflers) , I seem to be getting a really high pitched hum in the cabin usually after 10-15 mph. It definitely gets annoying after driving for a while so I am not sure how to fix this?

Thanks!

bfritzsch · 05-11-2015, 10:12 PM

I just installed my pe exhaust and dont have this issue did you plug the vacuum line? I used a golf tee...

akerns429 · 05-11-2015, 10:25 PM

Quote:

Originally Posted by bfritzsch

I just installed my pe exhaust and dont have this issue did you plug the vacuum line? I used a golf tee...

I did not. I can't find where the end of the line is under the car. I had a muffler shop install the mufflers and didn't think about telling them to plug the line. Is there another spot the line can be plugged?

bfritzsch · 05-12-2015, 08:50 AM

well the only place I could find to tuck the tubing was behind the heat shielding right next to the muffler (silver stuff).

So I would try to get under your car and reach you hand behind the heat shielding and feel around for a small tube.

That is where the tube actually comes from prior to doing the swap anyway so I would think it has to be back there.

Dconnelly9191 · 05-12-2015, 10:51 AM

Could you not just disconnect the plug by the rear break lights that controls that vac line?

akerns429 · 05-12-2015, 11:46 AM

Quote:

Originally Posted by Dconnelly9191

Could you not just disconnect the plug by the rear break lights that controls that vac line?

Thanks for everyone's help! That is exactly what I finally did this morning and no more noise! Just the intoxicating sound of pure turbo goodness

.

Now if I can figure out how to get my performance exhaust to sound louder... Since it's an N55 I guess my car wouldn't have come with a resonator unless it's built into the X pipe. So all that would be left is the secondary cats and a downpipe?

Johnny Boost · 05-12-2015, 11:56 AM

Quote:

Originally Posted by akerns429

Quote:

Originally Posted by Dconnelly9191

Could you not just disconnect the plug by the rear break lights that controls that vac line?

Thanks for everyone's help! That is exactly what I finally did this morning and no more noise! Just the intoxicating sound of pure turbo goodness

.

Now if I can figure out how to get my performance exhaust to sound louder... Since it's an N55 I guess my car wouldn't have come with a resonator unless it's built into the X pipe. So all that would be left is the secondary cats and a downpipe?

A downpipe will do the trick

ETM3 · 05-13-2015, 02:03 PM

Does your car have secondary cats? I have a 2011 e93 335i m-sport, and do not believe I have secondary cats.

aren93 · 05-13-2015, 03:26 PM

Quote:

Originally Posted by akerns429

Hey guys,

So I recently had my performance exhaust installed on my car. Since there isn't a flap in the muffler that the vacuum line connects to (like the stock mufflers) , I seem to be getting a really high pitched hum in the cabin usually after 10-15 mph. It definitely gets annoying after driving for a while so I am not sure how to fix this?

Thanks!

I had the same exact problem a while ago, glad you figured out how to fix it too.

akerns429 · 05-14-2015, 03:55 PM

Quote:

Originally Posted by EricT335i

Does your car have secondary cats? I have a 2011 e93 335i m-sport, and do not believe I have secondary cats.

It does.. Do you know if it will help make the exhaust louder if I removed them? Eventually I'll throw a cat less down pipe on her, but probably not until I decide on a tune.

AW-335i · 05-15-2015, 02:41 PM

Quote:

Originally Posted by akerns429

Hey guys,

So I recently had my performance exhaust installed on my car. Since there isn't a flap in the muffler that the vacuum line connects to (like the stock mufflers) , I seem to be getting a really high pitched hum in the cabin usually after 10-15 mph. It definitely gets annoying after driving for a while so I am not sure how to fix this?

Thanks!

The BMW performance exhaust should have a metal rod protruding from the driver's side muffler. The metal rod is located near to where the vacuum flap on the OEM exhaust would be. According to the shop that installed my exhaust, the sole purpose of the rod is for connecting to the no longer needed vacuum line. My vacuum line is plugged onto this metal rod.

akerns429 · 05-15-2015, 06:00 PM

Quote:

Originally Posted by akerns429

It does.. Do you know if it will help make the exhaust louder if I removed them? Eventually I'll throw a cat less down pipe on her, but probably not until I decide on a tune.

Any feedback on the above? I have an appointment tomorrow to get my cats off so just wanted to see what you guys think.

Thanks!

tkong · 05-15-2015, 06:42 PM

Quote:

Originally Posted by AW-335i

Quote:

Originally Posted by akerns429

Hey guys,

So I recently had my performance exhaust installed on my car. Since there isn't a flap in the muffler that the vacuum line connects to (like the stock mufflers) , I seem to be getting a really high pitched hum in the cabin usually after 10-15 mph. It definitely gets annoying after driving for a while so I am not sure how to fix this?

Thanks!

The BMW performance exhaust should have a metal rod protruding from the driver's side muffler. The metal rod is located near to where the vacuum flap on the OEM exhaust would be. According to the shop that installed my exhaust, the sole purpose of the rod is for connecting to the no longer needed vacuum line. My vacuum line is plugged onto this metal rod.

X2 this is what my exhaust shop did as well

ETM3 · 05-16-2015, 06:36 AM

I was catless and my car has no secnd cat. I recently did the pe exhuast mod and it was way too loud "drone rasp interior rumble city" at 2-4k rpm. I threw a pair of vibrant resonators on the midpipe (exactly where your secondary cats are) and now it sounds so awesome no drone and sounds exotic when you get in it. Those burbles and pops are intoxicating! 😄

If you plan on removing your main cat sometime down the road, I would replace the second cats with vibrant 1790 for now, then remove the main cat. You will love the setup.

bkkick · 04-30-2024, 12:19 PM

Quote:

Originally Posted by akerns429

Thanks for everyone's help! That is exactly what I finally did this morning and no more noise! Just the intoxicating sound of pure turbo goodness

.

Now if I can figure out how to get my performance exhaust to sound louder... Since it's an N55 I guess my car wouldn't have come with a resonator unless it's built into the X pipe. So all that would be left is the secondary cats and a downpipe?

I cant find the plug by the rear break lights that controls that vac line. Any pic of the location where exacly that is?

bkkick · 04-30-2024, 12:21 PM

Quote:

Originally Posted by Dconnelly9191

Could you not just disconnect the plug by the rear break lights that controls that vac line?

I tried to find the plug by the rear break lights that controls that vac line, but no luck. Any pic of the location where exacly that might be?

05-11-2015, 09:46 PM	#1
akerns429 Private First Class 35 Rep 197 Posts Drives: '15 f22 BMW m235i Join Date: Jul 2014 Location: spain iTrader: (1)	335i Exhaust Vacuum line noise Hey guys, So I recently had my performance exhaust installed on my car. Since there isn't a flap in the muffler that the vacuum line connects to (like the stock mufflers) , I seem to be getting a really high pitched hum in the cabin usually after 10-15 mph. It definitely gets annoying after driving for a while so I am not sure how to fix this? Thanks!
	Appreciate 0 Tweet Quote

05-11-2015, 10:12 PM	#2
bfritzsch Private First Class 22 Rep 170 Posts Drives: '11 e90 335i xDrive M-Sport Join Date: Nov 2012 Location: New Jersey iTrader: (0) Garage List 2011 335i xDrive (e90) [0.00]	I just installed my pe exhaust and dont have this issue did you plug the vacuum line? I used a golf tee... __________________ 2011 335i X-Drive (e90) - M-sport 6MT - LeMans Blue ( BMS CP / VRSF DP / BMS Intake / ER Sport Oil Cooler / ER Intercooler / Cobb v3)
	Appreciate 0 Quote

05-12-2015, 08:50 AM	#4
bfritzsch Private First Class 22 Rep 170 Posts Drives: '11 e90 335i xDrive M-Sport Join Date: Nov 2012 Location: New Jersey iTrader: (0) Garage List 2011 335i xDrive (e90) [0.00]	well the only place I could find to tuck the tubing was behind the heat shielding right next to the muffler (silver stuff). So I would try to get under your car and reach you hand behind the heat shielding and feel around for a small tube. That is where the tube actually comes from prior to doing the swap anyway so I would think it has to be back there. __________________ 2011 335i X-Drive (e90) - M-sport 6MT - LeMans Blue ( BMS CP / VRSF DP / BMS Intake / ER Sport Oil Cooler / ER Intercooler / Cobb v3)
	Appreciate 0 Quote

05-12-2015, 10:51 AM	#5
Dconnelly9191 Private 8 Rep 79 Posts Drives: 2011 335i Xdrive Coupe Join Date: Oct 2013 Location: Colorado Springs iTrader: (1) Garage List 2011 BMW 335i Xdrive [0.00]	Could you not just disconnect the plug by the rear break lights that controls that vac line?
	Appreciate 0 Quote

05-13-2015, 02:03 PM	#8
ETM3 Private 87 Rep 78 Posts Drives: 2011 Jerez Black E90 M3 Join Date: Apr 2015 Location: Los Angeles iTrader: (0)	Does your car have secondary cats? I have a 2011 e93 335i m-sport, and do not believe I have secondary cats.
	Appreciate 0 Quote

05-16-2015, 06:36 AM	#14
ETM3 Private 87 Rep 78 Posts Drives: 2011 Jerez Black E90 M3 Join Date: Apr 2015 Location: Los Angeles iTrader: (0)	I was catless and my car has no secnd cat. I recently did the pe exhuast mod and it was way too loud "drone rasp interior rumble city" at 2-4k rpm. I threw a pair of vibrant resonators on the midpipe (exactly where your secondary cats are) and now it sounds so awesome no drone and sounds exotic when you get in it. Those burbles and pops are intoxicating! 😄 If you plan on removing your main cat sometime down the road, I would replace the second cats with vibrant 1790 for now, then remove the main cat. You will love the setup.
	Appreciate 0 Quote