[sleepy75]

So after I installed the PSI midpipe, I am getting a massive rattle upon cold start. Just wondering if anyone else has experienced this. I think it may be the valves flapping but I'm not sure how to diagnose it. All I know is that this rattle is horrific. Still there even in comfort engine mode although not quite as bad. The system sounds great after the cold start has completed. If it is the valves flapping I'm afraid I may have to wire them open. I'd really hate to lose the valve functionality though.

[beachBmmr]

Originally Posted by sleepy75

So after I installed the PSI midpipe, I am getting a massive rattle upon cold start. Just wondering if anyone else has experienced this. I think it may be the valves flapping but I'm not sure how to diagnose it. All I know is that this rattle is horrific. Still there even in comfort engine mode although not quite as bad. The system sounds great after the cold start has completed. If it is the valves flapping I'm afraid I may have to wire them open. I'd really hate to lose the valve functionality though.

People have reported rattling against the tunnel brace under the car. Have you checked that?

[barryc365]

Yeah the pipe could be rattling off the brace as others have reported. Same with the Valvetronic

Apparently this is caused by cutting the exhaust in the wrong place.

My Valvetronic just arrived today so will definitely be cautious with the install.

You could get around this by adding some washers to the brace (not ideal), or having the exhaust adjusted.

I don't think it's the valves

[Soylent]

I bet the X pipe is sitting on the cross brace like mine. You can put a few ss washers under each bolt.

[sleepy75]

I can now confirm that the obnoxious cold start rattle is neither the cross brace clearance or the exhaust flaps. I temporarily removed the brace and wired the valves open. Proceeded to cold start with the same result. The only thing that begins to manage it is comfort mode with the exhaust sound button off. Again, the noise is only during cold start. After that completes (10 seconds?) everything sounds awesome.

[beachBmmr]

Originally Posted by sleepy75

I can now confirm that the obnoxious cold start rattle is neither the cross brace clearance or the exhaust flaps. I temporarily removed the brace and wired the valves open. Proceeded to cold start with the same result. The only thing that begins to manage it is comfort mode with the exhaust sound button off. Again, the noise is only during cold start. After that completes (10 seconds?) everything sounds awesome.

All your flange bolts tight up front? If you get under the car and shake it by hand can you reproduce it? Maybe a loose mount?

[Pantagathus]

Originally Posted by barryc365

Yeah the pipe could be rattling off the brace as others have reported. Same with the Valvetronic

Apparently this is caused by cutting the exhaust in the wrong place.

My Valvetronic just arrived today so will definitely be cautious with the install.

You could get around this by adding some washers to the brace (not ideal), or having the exhaust adjusted.

I don't think it's the valves

When did you order your valvetronic? Got the generic "waiting on more parts" update today. It seems to have gone very quiet after some initial people receiving

[barryc365]

Originally Posted by Pantagathus

When did you order your valvetronic? Got the generic "waiting on more parts" update today. It seems to have gone very quiet after some initial people receiving

I only ordered it about 5 weeks ago…pretty decent considering some guys ordered in April and only got theirs recently too.
They seem to have the materials now and are churning them out so you should be good soon I bet

[PLife]

You can hear the m cold start now. Mine doesnt touch the x brace and the cold start from bmw is fucking hilarious. Its not even good. I start in eco with valves shut and get the fuck out of the garage asap. Once its warmed up it sounds beautiful on startup. At the gas station sport plus im breaking people’s necks theyre like oh damn whats that!

[sleepy75]

Originally Posted by PLife

You can hear the m cold start now. Mine doesnt touch the x brace and the cold start from bmw is fucking hilarious. Its not even good. I start in eco with valves shut and get the fuck out of the garage asap. Once its warmed up it sounds beautiful on startup. At the gas station sport plus im breaking people’s necks theyre like oh damn whats that!

So it's not just me then. After putting the PSI mid on and firing her up for the first time, my kids came out of the house and asked if there was something wrong with my car. I was was questioning that myself. But I agree, after the cold start, it sounds great.

[beachBmmr]

Originally Posted by sleepy75

So it's not just me then. After putting the PSI mid on and firing her up for the first time, my kids came out of the house and asked if there was something wrong with my car. I was was questioning that myself. But I agree, after the cold start, it sounds great.

Video, or it didnt happen

[Soylent]

Originally Posted by sleepy75

So it's not just me then. After putting the PSI mid on and firing her up for the first time, my kids came out of the house and asked if there was something wrong with my car. I was was questioning that myself. But I agree, after the cold start, it sounds great.

I remote start mine from in the house in the morning. I don't want to be near it incase neighbors are out there walking.

[savi01]

Are there any videos for the cold start post-midpipe install? I'm on the fence about it, and have been worried about any rasp but it now seems that a cold start in non-eco mode sounds terrible? Or perhaps I'm misunderstanding.

[sleepy75]

Originally Posted by savi01

Are there any videos for the cold start post-midpipe install? I'm on the fence about it, and have been worried about any rasp but it now seems that a cold start in non-eco mode sounds terrible? Or perhaps I'm misunderstanding.

In my opinion, yes, the cold start sounds terrible. I’ll try to get a video of it up later tonight or tomorrow.

[PLife]

This isnt unique to the psi mid pipe. Any mid pipe or exhaust will sound like shit. Its the M performance cold start program. Its just absurd

https://g80.bimmerpost.com/forums/sh...1&postcount=44

I posted some warm starts here… as you can see it has nothing to do with the mid pipe. Its all running through the stock muffler, which determines the volume. The only difference between mid pipes is flow and pitch

[safridi]

Which cut mark are you guys cutting for valvetronic mp? I would assume middle

[PLife]

Originally Posted by safridi

Which cut mark are you guys cutting for valvetronic mp? I would assume middle

Yes middle

[FISH22]

Stumbled across this thread. I too have a pretty obnoxious cold-start with my PSI mid pipe. No vibrating or rubbing on the crossmember, and it seems like it's just the frequency/pulses of the exhaust during the cold-start. The buzzing sound is most definitely coming from the rear muffler section.

I could see how this is going to happen with any mid-pipe. I wonder if this would change with a different rear section (along with being louder, just no buzzing/vibrating).

Either way, thankful it only lasts a few seconds. Otherwise, extremely happy with the PSI pipe. Car sounds damn epic in full sport+.

[mike@x-ph.com]

cant wait for bm3 so i can disable the cold start

[corbinwilliams]

Originally Posted by sleepy75

So after I installed the PSI midpipe, I am getting a massive rattle upon cold start. Just wondering if anyone else has experienced this. I think it may be the valves flapping but I'm not sure how to diagnose it. All I know is that this rattle is horrific. Still there even in comfort engine mode although not quite as bad. The system sounds great after the cold start has completed. If it is the valves flapping I'm afraid I may have to wire them open. I'd really hate to lose the valve functionality though.

Sean@PSI any ideas what is causing this? Seems it might be the cold start program of the vehicles.. I can't wait to get my PSI midpipe, but first I need the car

[TrentMeister]

Originally Posted by PLife

You can hear the m cold start now. Mine doesnt touch the x brace and the cold start from bmw is fucking hilarious. Its not even good. I start in eco with valves shut and get the fuck out of the garage asap. Once its warmed up it sounds beautiful on startup. At the gas station sport plus im breaking people's necks theyre like oh damn whats that!

Yeah warm start S+ is truly an excellent sonic experience

[FISH22]

I fiddled with the valves and safety wired them open, just to see the impact on the cold start paired with mid pipe… dear god, sounded like the world was ending. So loud.