Sound from Passenger Side - 986 Forum - The Community for Porsche Boxster & Cayman Owners

tifosi00 · 07-02-2006, 01:51 PM

Hello,
Can anyone help me with this? I have explained it to the dealer numerous times, only for them to tell me they don't hear anything. I have a 2000 base boxster that has been lowered with aftermarket rims. I get a loud humming noise when in either 2 or 3 gear around 3,000 rpm coming from the passenger side. When it starts to happen, if I either rev the engine more or take my foot off the gas it will stop. It has actually been happening for a couple years now, before and after I lowered the car, through 2 different sets of tires, so it's not the tires. I am thinking it's a bearing, but that wouldn't really explain why it goes away when I either step on the gas more or let off the gas.

Any help would be greatly appreciated.

Thanks!

deliriousga · 07-04-2006, 07:26 AM

Flywheel. The flywheel can get out of balance because it is a dual mass flywheel and I'm sure it's not a good thing for the pilot bearing. Ours does the same thing in the 3000-3200 rpm range. I'm replacing the flywheel when it's time for a clutch job, then it should be good to go again. The same problem occurs in other cars (Audis, etc.) that have the dual mass flywheel.

If it's driven properly at around the 4K rpm range, you rarely notice it so keep it up a little.

mach schnell · 07-04-2006, 09:43 AM

can you find a highly recommended private porsche mechanic - one who has no reason to deny the existence of a problem for warrantable problem. not suggesting you need to have the private guy fix the problem (unless of course it's not a warrantable problem and you end up paying the dealer as well). but if it is a problem that would be covered by warranty, have the private mechanic find and document it then take that to Porsche. o/w have the private guy find and fix the prob. if anything, the private mechanic may be more willing to explore the problem or may have previous experience with the same prob.

good luck

donv · 07-04-2006, 04:04 PM

Does it appear to be coming from the rear edge of the passenger door? Sound more like a resonance issue (a sympathetic vibration rather than the source of the vibration)? If so, it may be related to the door handle hardware. The low RPMs you mention are about the same vibration level as the music I can use to induce the same noise in my car dependably. The fact that when you change the RPMs even a little bit it stops sounds very much like a resonance problem. It is way louder than you'd expect and has a "thick stiff wire buzzing in a bushing" sort of sound to it. Might be the hum you're encountering. I've yet to take the door apart to fix it (I just avoid that CD now

) but it should be an easy fix as it just needs to be modified slightly to change the resonance point.

Quote:

Originally Posted by tifosi00

Hello,
Can anyone help me with this? I have explained it to the dealer numerous times, only for them to tell me they don't hear anything. I have a 2000 base boxster that has been lowered with aftermarket rims. I get a loud humming noise when in either 2 or 3 gear around 3,000 rpm coming from the passenger side. When it starts to happen, if I either rev the engine more or take my foot off the gas it will stop. It has actually been happening for a couple years now, before and after I lowered the car, through 2 different sets of tires, so it's not the tires. I am thinking it's a bearing, but that wouldn't really explain why it goes away when I either step on the gas more or let off the gas.

Any help would be greatly appreciated.

Thanks!

insite · 07-04-2006, 07:59 PM

Quote:

Originally Posted by tifosi00

Hello,
Can anyone help me with this? I have explained it to the dealer numerous times, only for them to tell me they don't hear anything. I have a 2000 base boxster that has been lowered with aftermarket rims. I get a loud humming noise when in either 2 or 3 gear around 3,000 rpm coming from the passenger side. When it starts to happen, if I either rev the engine more or take my foot off the gas it will stop. It has actually been happening for a couple years now, before and after I lowered the car, through 2 different sets of tires, so it's not the tires. I am thinking it's a bearing, but that wouldn't really explain why it goes away when I either step on the gas more or let off the gas.

Any help would be greatly appreciated.

Thanks!

two more possibilities:

1. tire is rubbing the e-brake cable (if your aftermarket rims are wide, this can be an issue)

2. cv joint going bad.

does the hum sound like a chassis thing or a motor thing? could also be some sort of vacuum leak.

tifosi00 · 07-05-2006, 06:05 AM

thank you for all your advice, and thoughts.

One thing I forgot to mention is that it seems to start more often when I start to turn slightly right. I do have aftermarket wheels that are wider, 9 inch in the front and 10 in the back.

The weird thing is it doesn't start only when turning right, it sometimes starts in a straight line, but most often when I start to turn right, then will go away when I turn straight again.

I will check out the emergency brake cable, I had not thought of that before.

If it has something to do with the flywheel, I will just leave it until I need a new clutch.

My car is out of warrantly, I have 60,000 miles on it now.

Thanks again for any thoughts.

Mike

insite · 07-05-2006, 06:36 AM

i have 10" rims w/ P275's. when i first installed them, they rubbed the ebrake cable on the passenger side. i then zip tied it to the trailing arm and things were fine.

i later found out that i had some excessive toe in the rear; after an alignment, the cable no longer rubbed. check it out, it sounds very similar to my experience.