muffler valve/golf tee alternative---
 

Reading posts about forcing the muffler tailpipe valve to stay open by removing the vacuum hose and plugging it---If you open the rear hatch and remove the drivers side cover (where the DVD and Sat radio go) you will see a small solenoid valve with 2 vacuum hoses attached--the soft hose goes directly to the vacuum pot on the muffler--you can disconnect it at the solenoid valve and put a short piece of plugged hose in the valve output--now you don't have to crawl under the car and if you go for service no one will see the hose with a golf tee stuck in it! Should be goood for about 15 to 20 HP and 3 to 5 MPG by my dyno reading :nanana:

I just doubled the hose over and tied it. No disconnecting, no plugging of open valves or hoses, no potential loss of vacuum in the system.

What did the modification do for you--I'll bet with the V8 the exhaust tone is nicer!

:rofl: Sorry, I should have been more specific. It wasn't on my X5, it was on my 330. As far as I know the 3 litre M54 is the only engine that has the muffler valve.

It sounds much louder on startup and the exhaust note is much more noticable at lower RPMs. I found no noticable effect on performance or mileage. Hey, what do you want for a free mod? ;)

Yes just got back from a ride--the exhaust is definitely nicer--I like it--can't beat a free modification!

warranty
 

Does this cause any warning lights in the system? Did you notice an increase in power? Can you show a picture of it?:)

Shouldn't do any damage or increase in power. The sport package does not have one of these devices installed on the muffler and is rated that same as a non sport. Maybe it's a stainless tips on my muffler that make it go so fast.

No warning lights--as far as power goes when the throttle is opened far the valve opens anyway--so either way at full throttle its the same--its worth it for the sound--it now sounds like my Z4 with the drilled out muffler. May be more at lower throttle openings because both tailpipes are wide open??

Muffler vacum cap off
 

I found the valve right where you said it was and capped the soft side to the vacum assembly. It is a little louder at low rpm's and it seems to run at about 200 lower at 25 in second gear for example.

Some have reported on other BMW sites, that some dealers are even doing this mod. ;)

I've been planning on doing this for such a long time, but keep forgetting to do so. Anyone happen to know where the vaccum lines are under the X5 3.0?