Have a technical question about my M5 and I thought I'd ask here as well

undecided · 01-20-2010, 07:39 PM

Since there are a lot of very knowledgeable people here. I am taking in to the dealer for a checkup but here's what's going on.
I am comparing it to my friend's M5 and mine sounds rougher & louder. It sounds a lot more throaty in a good way I guess but the difference in sound levels is such that I want to have it checked out. Mine at part throttle is as loud as his at full throttle. My car sounds like the Mustang vs GTO chase in Bullit. The car is completely stock. Do you guys know of anything that will make an engine feel and sound rougher? We both have about the same mileage and there's not CEL or anything to indicate a malfunction. The car pulls like a freight train.

Thx

Curt2000 · 01-20-2010, 07:59 PM

Sounds like a golf tee mod was performed but I'm unsure if the M5 has the valved silencer in the stock exhaust???

As for it running rough...not sure about that, might have a timing issue?

Did you purchase the car used?

undecided · 01-20-2010, 08:37 PM

Quote:

Originally Posted by Curt2000

Sounds like a golf tee mod was performed but I'm unsure if the M5 has the valved silencer in the stock exhaust???

As for it running rough...not sure about that, might have a timing issue?

Did you purchase the car used?

When I say rough, it's not like it's dying or anything, it's just rougher than my friend's. Some may say mine sounds better since it sound like it's more free flowing. It's hard to explain but it sounds like it has more of a V8 "burble". My friend's is as quiet as a 550i unless he floors it, then it's loud. Mine at partial throttle is as loud as his on WOT.

Curt2000 · 01-20-2010, 08:45 PM

OK, sounds like you have a blockage in the vacuum line that controls a valve in the muffler. at idle and partial throttle the valve is closed only allowing exhaust to flow through one of the tail pipes...at WOT the valve opens and allows the exhaust through all of the tail pipes, thus making it louder and more free flowing.

Guys on here do it all the time, its called the golf tee mod because they break off a golf tee in the vacuum line to cause the blockage that forces the valve to stay open and have a more aggressive tone at idle.

But like I said before...the M5 might not have these valves in the exhaust so I may be way off.

undecided · 01-20-2010, 09:43 PM

Quote:

Originally Posted by Curt2000

OK, sounds like you have a blockage in the vacuum line that controls a valve in the muffler. at idle and partial throttle the valve is closed only allowing exhaust to flow through one of the tail pipes...at WOT the valve opens and allows the exhaust through all of the tail pipes, thus making it louder and more free flowing.

Guys on here do it all the time, its called the golf tee mod because they break off a golf tee in the vacuum line to cause the blockage that forces the valve to stay open and have a more aggressive tone at idle.

But like I said before...the M5 might not have these valves in the exhaust so I may be way off.

thx again

GreenPlease · 01-20-2010, 10:17 PM

Curt's explanation is probable but I can neither confirm nor deny that the M5 has the same exhaust valve. If there is a blockage in the vacuum it will throw a code that your dealer will see.

JoosyJoos · 01-20-2010, 10:20 PM

Something else to consider...

You're friends car may not be run very hard and may have some carbon built up in the exhaust. You could have purchased a car that was run like it was meant to be and it doesn't have that carbon built up.

The M coupes at the Nurburgring are way louder than my fathers and the only difference is how hard they are run and that amount of junk in the exhaust piping.

ren · 01-21-2010, 03:36 AM

I don't know much about the M5 progman versions, but for the N54 engine the software version is enough to make that kind of a difference. I see that you have a 2008 version, what year is your friend's?

thefireant · 01-21-2010, 04:53 AM

Let me just say it was the Mustang VS challenger race in bullit. Not a GTO.

just FYI

TMR · 01-21-2010, 08:16 AM

Maybe you have a Wednesday car.

CubanJJ09 · 01-21-2010, 08:29 AM

maybe one of your baffles in the mufflers

undecided · 01-21-2010, 08:35 AM

Quote:

Originally Posted by thefireant

Let me just say it was the Mustang VS challenger race in bullit. Not a GTO.

just FYI

Oh well, good to know.

undecided · 01-21-2010, 08:36 AM

Quote:

Originally Posted by TMR

Maybe you have a Wednesday car.

hehehe

undecided · 01-21-2010, 08:38 AM

Quote:

Originally Posted by GreenPlease

Curt's explanation is probable but I can neither confirm nor deny that the M5 has the same exhaust valve. If there is a blockage in the vacuum it will throw a code that your dealer will see.

That's confirmed.

undecided · 01-21-2010, 08:39 AM

Quote:

Originally Posted by erensf

I don't know much about the M5 progman versions, but for the N54 engine the software version is enough to make that kind of a difference. I see that you have a 2008 version, what year is your friend's?

And there have been a few progmans in between.

fast4door · 01-21-2010, 10:32 AM

could be a software realted issue..sometimes the programms can make your car sound louder or quiter..could be that you and your friend are running different software versions

01-20-2010, 07:39 PM	#1
undecided Captain 83 Rep 985 Posts Drives: 08 M5 Sapphire Black Join Date: Oct 2005 Location: CT iTrader: (0) Garage List 2008 335xi SOLD!!!! ... [0.00] 2008 M5 [0.00]	Have a technical question about my M5 and I thought I'd ask here as well Since there are a lot of very knowledgeable people here. I am taking in to the dealer for a checkup but here's what's going on. I am comparing it to my friend's M5 and mine sounds rougher & louder. It sounds a lot more throaty in a good way I guess but the difference in sound levels is such that I want to have it checked out. Mine at part throttle is as loud as his at full throttle. My car sounds like the Mustang vs GTO chase in Bullit. The car is completely stock. Do you guys know of anything that will make an engine feel and sound rougher? We both have about the same mileage and there's not CEL or anything to indicate a malfunction. The car pulls like a freight train. Thx
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01-20-2010, 07:59 PM	#2
Curt2000 Brigadier General 1013 Rep 3,157 Posts Drives: '93 Supra Turbo Join Date: Jun 2007 Location: Washington D.C. iTrader: (25)	Sounds like a golf tee mod was performed but I'm unsure if the M5 has the valved silencer in the stock exhaust??? As for it running rough...not sure about that, might have a timing issue? Did you purchase the car used? __________________ Former Car: '16 SUNBURST GOLD F80 ///M3--6MT/Carbon Cloth (ED Thread) Former Car:'13 SANTORINI BLUE E92///M3--6MT/Speed Cloth/ZCP(ED Thread) INSTAGRAM:@C2KMotorsports
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01-20-2010, 08:45 PM	#4
Curt2000 Brigadier General 1013 Rep 3,157 Posts Drives: '93 Supra Turbo Join Date: Jun 2007 Location: Washington D.C. iTrader: (25)	OK, sounds like you have a blockage in the vacuum line that controls a valve in the muffler. at idle and partial throttle the valve is closed only allowing exhaust to flow through one of the tail pipes...at WOT the valve opens and allows the exhaust through all of the tail pipes, thus making it louder and more free flowing. Guys on here do it all the time, its called the golf tee mod because they break off a golf tee in the vacuum line to cause the blockage that forces the valve to stay open and have a more aggressive tone at idle. But like I said before...the M5 might not have these valves in the exhaust so I may be way off. __________________ Former Car: '16 SUNBURST GOLD F80 ///M3--6MT/Carbon Cloth (ED Thread) Former Car:'13 SANTORINI BLUE E92///M3--6MT/Speed Cloth/ZCP(ED Thread) INSTAGRAM:@C2KMotorsports
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01-20-2010, 10:17 PM	#6
GreenPlease Lieutenant Colonel 129 Rep 1,629 Posts Drives: BMW 335i e92 Join Date: Feb 2008 Location: Orlando Florida iTrader: (2)	Curt's explanation is probable but I can neither confirm nor deny that the M5 has the same exhaust valve. If there is a blockage in the vacuum it will throw a code that your dealer will see. __________________ Cars>Women
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01-20-2010, 10:20 PM	#7
JoosyJoos Major 113 Rep 1,347 Posts Drives: 2011 335d Join Date: Apr 2007 Location: Atlanta, GA iTrader: (1) Garage List 2008 BMW 335i [0.00]	Something else to consider... You're friends car may not be run very hard and may have some carbon built up in the exhaust. You could have purchased a car that was run like it was meant to be and it doesn't have that carbon built up. The M coupes at the Nurburgring are way louder than my fathers and the only difference is how hard they are run and that amount of junk in the exhaust piping. __________________ 1997 M3 Coupe - BMWCCA I-Prepared #22 2006 M Roadster - 23,000 miles and slowly counting
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01-21-2010, 03:36 AM	#8
ren Captain 62 Rep 839 Posts Drives: 2024 X7 M60i Join Date: Jan 2007 Location: U.S. iTrader: (8)	I don't know much about the M5 progman versions, but for the N54 engine the software version is enough to make that kind of a difference. I see that you have a 2008 version, what year is your friend's?
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01-21-2010, 04:53 AM	#9
thefireant Just browsing for now... 2 Rep 219 Posts Drives: 2006 Pontiac GTO Join Date: Jan 2010 Location: All over the place iTrader: (0)	Let me just say it was the Mustang VS challenger race in bullit. Not a GTO. just FYI __________________ Cavalier XL
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01-21-2010, 08:16 AM	#10
TMR Brigadier General 394 Rep 3,161 Posts Drives: M3 Join Date: Jun 2008 Location: Torrance iTrader: (12)	Maybe you have a Wednesday car. __________________ 2015 M3 BPM Tuned, Eibach, Magnaflow and more www.tmrmzine.com/m3/f80 SOLD E92 Slēk Carbon Fiber Widebody M3 www.tmrmzine.com/m3/slek/ SOLD E92 335i Stage 3+ with all the toys www.tmrmzine.com/335/ SOLD E39 M5 Modded, What a great car! www.tmrmzine.com/m5/
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01-21-2010, 08:29 AM	#11
CubanJJ09 Banned 169 Rep 12,680 Posts Drives: like an asshole Join Date: Feb 2008 Location: Chicago Burbs iTrader: (2) Garage List 2007 BMW 335i [6.18]	maybe one of your baffles in the mufflers
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01-21-2010, 10:32 AM	#16
fast4door Captain 29 Rep 802 Posts Drives: E60 M5 Join Date: Sep 2009 Location: Davie, FL iTrader: (3)	could be a software realted issue..sometimes the programms can make your car sound louder or quiter..could be that you and your friend are running different software versions
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