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Discussion Starter · #1 ·
Hopefully this isn't a stupid questiion. I've never driven a V8 and am not sure if it's just a way the engine sounds.... When doing at low RPMs, particularly in 5th and 6th gear, say 1500-1900 RPM range, just cruising the local roads, I hear a "revolving" sound coming. It's a constant sound that seems to make about 1 audible "rotation" per second with the pitch going down and that back up as it comes around with the "top" of the rotation being the highest.

Hopefully this makes sense! It's definately coming from something spinning.. which is a lot of potential things!
 

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Check your tires, I had the same problem with my 540/6spd, I was running Yokohama ES100. Horrible tires very noisy and loud. I actually thought my bearings were bad, until my mechanic told me it was the tires. Replaced tires problem solved. Good Luck:typing:
 

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It definitly sounds like your tires are the cause! What type of tires are you using?
 

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Discussion Starter · #4 ·
Tires are Pilot Sports. THese are not known for noise from what I've read. I noticed the same noise today in lower gears, same average RPM's.

I don't really have any vibration issues that lead me to believe there may be a balancing issue.
 

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First of all, check the tyre pressures, and tighten the wheel bolts.

David
 

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Discussion Starter · #6 ·
Checked pressure yesterday. Front was 32, and rear was 38. 32 is too low for my tastes so I bumped to F37/R38. Not sure what the recommended pressures are by most M5 drivers but these seemed like a better combo to start with. I'll check the wheel bolts as well, didn't think of that.
 

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HDClown said:
Hopefully this isn't a stupid questiion. I've never driven a V8 and am not sure if it's just a way the engine sounds.... When doing at low RPMs, particularly in 5th and 6th gear, say 1500-1900 RPM range, just cruising the local roads, I hear a "revolving" sound coming. It's a constant sound that seems to make about 1 audible "rotation" per second with the pitch going down and that back up as it comes around with the "top" of the rotation being the highest.

Hopefully this makes sense! It's definately coming from something spinning.. which is a lot of potential things!
I notice the same phenomenon in my E39 M5 under steady-state cruising in the higher gears from time to time around 1800 rpm, and it was present from the very first day of ownership.

The purchase of my M5 qualified me for a weekend at BMW's performance center in Spartanburg, South Carolina. This weekend included a question and answer session with a BMW technical guru. According to this guru the E39 M5's V-8 engine has two points in the rpm range where there are natural secondary resonances. The most conspicuous of these occurs at around 1800 rpm. The other point is higher in the rpm range and is more subtle. I've never found it.

Because Atlanta is somewhat hilly, I don't spend much time cruising under throttle below 2000 rpm, so this oscillating engine sound doesn't bother me at all, but I can see how 1800 rpm cruising might be more useful in Florida.

It's not your tires, it's not abnormal, and it won't bring down your engine like the Walls of Jerico. ;)

Richard
 
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