Post Service Jitters - 986 Forum - The Community for Porsche Boxster & Cayman Owners

2.7boxer6 · 04-23-2010, 07:00 AM

Hey Guys,

Just got my 48000km service done at my P dealer and now when I bring the car just over 3000rpm and let off the gas I feel a noticeable vibration in my lower back as it goes through 3000-2950rpm.

Any ideas? It only happens at this exact rpm range and only when I lift of the gas. Feels most prevalent in 3rd.

Thanks.

tonycarreon · 04-23-2010, 07:04 AM

front motor mount

2.7boxer6 · 04-23-2010, 07:19 AM

I was thinking it could be something like that but I couldn't think of a reason why it would only be at that RPM. Wouldn't it rattle more coming off of it at a higher RPM?

Even when i step off the throttle at 5000rpm it only shimmies through that range (3000-2950rpm).

clickman · 04-23-2010, 08:00 AM

I have the same thing. My local PCar mech says it's common and you just have to live with it. If you search the forum(s) you'll find nothing definitive but a few potential causes: loose/poorly designed exhaust components, worn front motor mount, clutch issues. I haven't done anything about mine.

tonycarreon · 04-23-2010, 12:51 PM

mine did it at lower RPMs and when slowing down, though in not such a small interval. it might just be a natural thing with your car you've never noticed. however with the mileage it's probably time to at least investigate it - especially if you've never done it. (whoops, just did the metric to english conversion

)

extanker · 04-23-2010, 01:04 PM

ya just came from service ? aside from the noisey brakes and bad vibes did they do any thing good ?

2.7boxer6 · 04-23-2010, 01:57 PM

LOL yeah everything is running smoother other than the shimmy. The brakes have always been noisy. Also to be fair I rarely took it above 3000rpm before I read the <2800rpm = IMS failure tread, so I may just not have ever noticed it before..

Just got off the phone with the P mech actually, He says that most porsches have squeaky brakes during light braking due to the metallic content in the pads..

He also said that other boxster owners experience this vibration and that 3000rpm is the most turbulent point in the rev range. He also acknowledged that it could be a "tired" front motor mount.

He offered a rid along next week which I'll probably take him up on.

yimmy149 · 04-23-2010, 02:13 PM

When I bought my Boxster @ 47k miles, the mount was shot - and I didn't ever feel the engine. Now that I have an enthusiast mount, the engine is louder most of the time, and transmits a vibration to the seat around 3000k RPM. If you buy a new Porsche mount, you will probably eliminate the vibration and get better quality shifts. Buying an aftermarket mount will keep the vibration, but get you better launches.

Oh, and my brakes also squeel a bit when they are warm, especially during the summer.

-james

2.7boxer6 · 04-23-2010, 06:43 PM

Good to know! Thanks Yimmy.

Anyone else with similar experiences?

2TrunkSteve · 04-23-2010, 09:50 PM

I had that same vibration and for some reason my clutch seemed to be difficult in reverse (48k miles at the time). It drove me nuts and my research suggested the motor mount. I purchased Pedro's remanufactured mount and I am very happy with the results. Pedro's top notch and he makes it as easy as possible to change this out.

Did it myself in about 3 hours - very satisfying when I was done.

www.pedrosgarage.com

2.7boxer6 · 04-27-2010, 10:51 AM

Thanks for the response steve,

I have been looking at the enthusiast mount is that what you got? A previous post said they still get vibes at 3000, do you? As for the install, I haven't done any work on the car myself other than the de-snorkel and changing a burnt out light! Would you think that I could do the install or would it be worth it to just get it done at the shop?

2TrunkSteve · 04-27-2010, 04:53 PM

That's the one.

I have average mechanical skills (at best) and a $150 set of Craftsmen tools along with a floor jack and jack stands. The only part I struggled with was getting the coolant hose clamps undone, they weren't hard to undue, I just couldn't quickly figure it out just by looking. Otherwise it wasn't too difficult. I would rate it a 3 out of 10 on the difficulty scale. I took my time and cleaned everything as I went. I could have done it faster if I had too.

As far as results, I didn't realize how bad off the car was until after I replaced the motor mount. I think it deteriorated gradually so that I didn't notice. I originally thought the clutch was going because reverse was difficult and the car would stall if you weren't careful with the clutch. The 3k RPM issue was bad too, so I figured I would start with the engine mount. I was suprised to find it fixed both issues. As far as the level of vibrations go, it's different than it was (much improved), but it's not Honda smooth. My car never was completely vibration free but I have no difference in the 3k RPM harshness over any other part of the powerband. It's a performance car and I expect some reasonable amount of harshness.