Downpipe Leak Question

RobsgottaM3 · 03-16-2013, 02:46 PM

I installed a set of PLM downpipes about 2 weeks ago and I think I have an exhaust leak but I am not 100% sure. It sounds like a rattle/hiss. Its only noticeable on startup when the engine is cold and under acceleration. If you have the windows up you can't hear it at all. If you rev the engine while in park or neutral you can't hear anything. I have replaced the gaskets from the DP to the mid-pipes but the sound didn’t change. Could it be the waste gates or turbo? I know it's hard to diagnose without hearing the actual sound but I wanted to see if anyone else ran into this problem. The car seems to be running fine until I get high in the RPM's then it seems to shudder. I haven’t had a chance to sun any logs yet. Any help would be greatly appreciated.

Rob

enrita · 03-16-2013, 03:08 PM

probably just WG rattle, normal when installing dps . as long as the car runs fine dont bother......

RobsgottaM3 · 03-16-2013, 03:15 PM

Quote:

Originally Posted by enrita

probably just WG rattle, normal when installing dps . as long as the car runs fine dont bother......

Anyway to cure the rattle? Adjustments?

enrita · 03-16-2013, 04:15 PM

Only way is with a tune

RobsgottaM3 · 03-16-2013, 04:22 PM

Quote:

Originally Posted by enrita

Only way is with a tune

Can you give a little more detail please? I have a JB4...

GTstunna612 · 03-16-2013, 04:59 PM

think there is a rattle fix you have to mess around with the JB4 settings...I will have to do the same since Im having my DPs installed in a few

RobsgottaM3 · 03-17-2013, 08:05 AM

I am planning on messing with the JB4 settings today. I will let you guys know what happens.

RobsgottaM3 · 03-17-2013, 10:07 AM

Changed the future use setting on the JB4 and it seems to have helped a little bit. Still getting a sound under acceleration. I am going to try and adjust the actuator arm. I hope this helps. I hate that my car sounds like a POS.

PINeely · 03-17-2013, 10:13 AM

Does your interior smell funny at idle? A leak between the turbo flange and downpipe lets exhaust gasses come in through the air conditioning and the cabin smells like exhaust. If you don't smell this then you could rule out a leak.

It does sound a lot like WG rattle from how you've described it. Did you check Youtube videos to see if you can find a match?

RobsgottaM3 · 03-17-2013, 10:20 AM

Quote:

Originally Posted by PINeely

Does your interior smell funny at idle? A leak between the turbo flange and downpipe lets exhaust gasses come in through the air conditioning and the cabin smells like exhaust. If you don't smell this then you could rule out a leak.

It does sound a lot like WG rattle from how you've described it. Did you check Youtube videos to see if you can find a match?

I don't have any type of smell in the car. I have watched the videos but it is hard to compare the sound with the quality of the videos. Too bad no one in my area is a expert.

PINeely · 03-17-2013, 10:44 AM

What a lot of people find out is that they have a minor wastegate rattle that they can't hear until they get downpipes which make it more audible. Another possibility is that the downpipes are rattling together. I had this happening on cold starts for a while and had to finally crawl under the car to adjust them.

Try the JB4 values if it seems to be helping. If you can't fix it with the JB4 values then you could check the pipes to see if they are touching anywhere. Anything to prevent having to adjust them manually.

Lux3m35i · 03-17-2013, 02:18 PM

I also have a noise since I installed DPs on acceleration/load. I don't hear anything on idle or if I rev up in neutral. If windows are closed, I have to listen carefully to hear it.

And yep it is hard to explain the sound.. like rattle/rasp..

I surely have WG rattle which can be eliminated with procede.
But if someone has WG rattle, you would probably hear it at idle or when you rev up in neutral and the RPM drops. Also on deceleration.

I will change my DPs on Tuesday because they don't fit well.. hopefully it will also eliminate this creepy sound!

But I worry that this sound is a normal sound which comes with catless DPs dependably on which exhaust you are using and the conditions of your exhaust/turbos.

Which exhaust do you have?

RobsgottaM3 · 03-17-2013, 03:51 PM

Quote:

Originally Posted by Lux3m35i

I also have a noise since I installed DPs on acceleration/load. I don't hear anything on idle or if I rev up in neutral. If windows are closed, I have to listen carefully to hear it.

And yep it is hard to explain the sound.. like rattle/rasp..

I surely have WG rattle which can be eliminated with procede.
But if someone has WG rattle, you would probably hear it at idle or when you rev up in neutral and the RPM drops. Also on deceleration.

I will change my DPs on Tuesday because they don't fit well.. hopefully it will also eliminate this creepy sound!

But I worry that this sound is a normal sound which comes with catless DPs dependably on which exhaust you are using and the conditions of your exhaust/turbos.

Which exhaust do you have?

I am running the stock exhaust with PLM DP's. I also have Cyba Tips but I know they have no effect on the sound.

Rookie83 · 03-18-2013, 09:50 AM

Ive noticed this as well after installing dp's. The best description i could give of mine is it sounds like bolts sitting on top of a vibrating piece of sheet metal or something. I always here it the loudest right a 3k rpm and then i goes away as soon as i get passed that.

Evochuck · 03-18-2013, 10:23 AM

Quote:

Originally Posted by Rookie83

Ive noticed this as well after installing dp's. The best description i could give of mine is it sounds like bolts sitting on top of a vibrating piece of sheet metal or something. I always here it the loudest right a 3k rpm and then i goes away as soon as i get passed that.

This could the RPM at wich the WG open at WOT (aka full boost so WG open to vent extra exhaust)

RobsgottaM3 · 03-18-2013, 01:24 PM

I wish I knew before installing the pipes. I wouldn't have. I would have spent the money on Meth for when I go to the track. This is just really pissing me off. Car sounds like a civic with crap exhaust.

Lux3m35i · 03-19-2013, 03:02 PM

Changed my DP's today an the new ones fit much better. But the noise didn't go away.

Did you guys ever tried natural aspirated (N/A) mode? Any difference?

Because if I change to N/A there is no difference at all. But if wastegate causes this problem the noise should disappear, right?

Or are we talking about "rasp"? Which comes with DPs depending on which exhaust you are using.

Ace_HollyWood · 03-19-2013, 05:49 PM

please list brands of DP's! it would help a ton! thanks

03-16-2013, 02:46 PM	#1
RobsgottaM3 Roll Tide Roll! 36 Rep 270 Posts Drives: E90/Slick-Top/Single Hump/6MT Join Date: Aug 2012 Location: Savannah GA iTrader: (0)	Downpipe Leak Question I installed a set of PLM downpipes about 2 weeks ago and I think I have an exhaust leak but I am not 100% sure. It sounds like a rattle/hiss. Its only noticeable on startup when the engine is cold and under acceleration. If you have the windows up you can't hear it at all. If you rev the engine while in park or neutral you can't hear anything. I have replaced the gaskets from the DP to the mid-pipes but the sound didn’t change. Could it be the waste gates or turbo? I know it's hard to diagnose without hearing the actual sound but I wanted to see if anyone else ran into this problem. The car seems to be running fine until I get high in the RPM's then it seems to shudder. I haven’t had a chance to sun any logs yet. Any help would be greatly appreciated. Rob __________________ *"You should never underestimate the predictability of stupidity."*
	Appreciate 0 Tweet Quote

03-16-2013, 03:08 PM	#2
enrita Major General 161 Rep 7,377 Posts Drives: 335i - Big turbos Join Date: Sep 2008 Location: Italian in Sweden iTrader: (0)	probably just WG rattle, normal when installing dps . as long as the car runs fine dont bother...... __________________ 07 335i AT - MOTIV 750 - MHD E85 BMS flash - BMS PI - JB4G5 - Okada Coils - NGK 5992 Plugs - Helix IC - Snow Stg. 3 - Stett CP - Custom midpipes with 100 HJS Cats - Bastuck Quad - PSS10 - QUAIFE LSD - BMS OCC - Forge DVs - AR OC - ALCON BBK - M3 Chassi - Dinan CP - Velocity M rear Toe arms - Advan RZ-DF - LUX H8 - Level 10 AT upgrade
	Appreciate 0 Quote

03-16-2013, 04:15 PM	#4
enrita Major General 161 Rep 7,377 Posts Drives: 335i - Big turbos Join Date: Sep 2008 Location: Italian in Sweden iTrader: (0)	Only way is with a tune
	Appreciate 0 Quote

03-16-2013, 04:59 PM	#6
GTstunna612 Lieutenant 52 Rep 512 Posts Drives: BMW Join Date: Feb 2008 Location: Tampa, FL iTrader: (0) Garage List E90 335i [0.00]	think there is a rattle fix you have to mess around with the JB4 settings...I will have to do the same since Im having my DPs installed in a few __________________ E90 335i Alpine White E90 328i Titanium Silver
	Appreciate 0 Quote

03-17-2013, 08:05 AM	#7
RobsgottaM3 Roll Tide Roll! 36 Rep 270 Posts Drives: E90/Slick-Top/Single Hump/6MT Join Date: Aug 2012 Location: Savannah GA iTrader: (0)	I am planning on messing with the JB4 settings today. I will let you guys know what happens. __________________ *"You should never underestimate the predictability of stupidity."*
	Appreciate 0 Quote

03-17-2013, 10:07 AM	#8
RobsgottaM3 Roll Tide Roll! 36 Rep 270 Posts Drives: E90/Slick-Top/Single Hump/6MT Join Date: Aug 2012 Location: Savannah GA iTrader: (0)	Changed the future use setting on the JB4 and it seems to have helped a little bit. Still getting a sound under acceleration. I am going to try and adjust the actuator arm. I hope this helps. I hate that my car sounds like a POS. __________________ *"You should never underestimate the predictability of stupidity."*
	Appreciate 0 Quote

03-17-2013, 10:13 AM	#9
PINeely Lieutenant Colonel 1080 Rep 1,912 Posts Drives: 2013 535i, 2015 Tundra 1794 Join Date: Jul 2009 Location: Jackson, MS iTrader: (2)	Does your interior smell funny at idle? A leak between the turbo flange and downpipe lets exhaust gasses come in through the air conditioning and the cabin smells like exhaust. If you don't smell this then you could rule out a leak. It does sound a lot like WG rattle from how you've described it. Did you check Youtube videos to see if you can find a match?
	Appreciate 0 Quote

03-17-2013, 10:44 AM	#11
PINeely Lieutenant Colonel 1080 Rep 1,912 Posts Drives: 2013 535i, 2015 Tundra 1794 Join Date: Jul 2009 Location: Jackson, MS iTrader: (2)	What a lot of people find out is that they have a minor wastegate rattle that they can't hear until they get downpipes which make it more audible. Another possibility is that the downpipes are rattling together. I had this happening on cold starts for a while and had to finally crawl under the car to adjust them. Try the JB4 values if it seems to be helping. If you can't fix it with the JB4 values then you could check the pipes to see if they are touching anywhere. Anything to prevent having to adjust them manually.
	Appreciate 0 Quote

03-17-2013, 02:18 PM	#12
Lux3m35i Private First Class 15 Rep 117 Posts Drives: E92 335i Coupe Join Date: Jun 2012 Location: Luxemburg iTrader: (0)	I also have a noise since I installed DPs on acceleration/load. I don't hear anything on idle or if I rev up in neutral. If windows are closed, I have to listen carefully to hear it. And yep it is hard to explain the sound.. like rattle/rasp.. I surely have WG rattle which can be eliminated with procede. But if someone has WG rattle, you would probably hear it at idle or when you rev up in neutral and the RPM drops. Also on deceleration. I will change my DPs on Tuesday because they don't fit well.. hopefully it will also eliminate this creepy sound! But I worry that this sound is a normal sound which comes with catless DPs dependably on which exhaust you are using and the conditions of your exhaust/turbos. Which exhaust do you have?
	Appreciate 0 Quote

03-18-2013, 09:50 AM	#14
Rookie83 First Lieutenant 15 Rep 380 Posts Drives: 2009 335i 6mt cpe Join Date: May 2011 Location: DFW iTrader: (1)	Ive noticed this as well after installing dp's. The best description i could give of mine is it sounds like bolts sitting on top of a vibrating piece of sheet metal or something. I always here it the loudest right a 3k rpm and then i goes away as soon as i get passed that. __________________ 09 tasman 335 6mt cpe, jb4 g5, bms dci, bms 3" catless dp's, 7"vrsf fmic, e85+93
	Appreciate 0 Quote

03-18-2013, 01:24 PM	#16
RobsgottaM3 Roll Tide Roll! 36 Rep 270 Posts Drives: E90/Slick-Top/Single Hump/6MT Join Date: Aug 2012 Location: Savannah GA iTrader: (0)	I wish I knew before installing the pipes. I wouldn't have. I would have spent the money on Meth for when I go to the track. This is just really pissing me off. Car sounds like a civic with crap exhaust. __________________ *"You should never underestimate the predictability of stupidity."*
	Appreciate 0 Quote

03-19-2013, 03:02 PM	#17
Lux3m35i Private First Class 15 Rep 117 Posts Drives: E92 335i Coupe Join Date: Jun 2012 Location: Luxemburg iTrader: (0)	Changed my DP's today an the new ones fit much better. But the noise didn't go away. Did you guys ever tried natural aspirated (N/A) mode? Any difference? Because if I change to N/A there is no difference at all. But if wastegate causes this problem the noise should disappear, right? Or are we talking about "rasp"? Which comes with DPs depending on which exhaust you are using.
	Appreciate 0 Quote

03-19-2013, 05:49 PM	#18
Ace_HollyWood Private First Class 8 Rep 122 Posts Drives: 2008 APW e92 335i Join Date: Feb 2012 Location: Cincinnati Ohio iTrader: (1)	please list brands of DP's! it would help a ton! thanks
	Appreciate 0 Quote