smlporsche

'03 Boxster S with 27K

I have a slight engine vibration from 3000 to 3200 RPM's. Does anyone have a clue as to what may be causing it?
Thanks.

blue2000s

It's usually the front engine mount.

Macster

As blue2000s mentioned the front engine mount can be broken.

May not be though. Some vibration around 3K is normal. The severity of the vibration can vary depending upon the road surface -- my experience is the smoother the road surface the more likely I'll notice the vibration -- and which gear the transmission (manual) is in. A lower gear, but not too low a gear, seems to encourage the vibration to appear.

Whether the vibration is normal or not depends upon how severe the vibration is and how often and consistent the vibration is. And of course if an check out of the motor/drivetrain mounts founds all intact and in good shape.

There seems to be some natural resonance around the 3K rpm mark and an otherwise very smooth running engine -- coworker described it as sewing machine smooth -- exhibits a bit of vibration that is noticable only because the engine's so smooth at all other rpms.

The fact there is an intake manifold flap or flaps that are activated at 3K which are to help take advantage of the intake system's resonsance at 3K (and above) may also play some role.

I had the front engine mount replaced in my 02 -- the rubber was cracked -- and the car did not vibrate any less after its replacement. Didn't vibrate any more either. IOWs, the vibration -- slight though it was -- was still present.

As for the motor mount, I didn't even know the mount was cracked, it was found by a mechanic who inspected the car while it was in for something else.

If the vibration is bothering you and it apparently is cause you're asking about it, have the engine/drivetrain mounts checked out by a qualified tech just to be sure no mounts are broken. You might ask for a second opinion to determine if the symptom is abnormal or you are just being overly sensitive to its presence.

Sincerely,

Macster.

smlporsche

Thanks guys.

The vibration is present when the car is standing still so I can rule out road conditions. In fact i have the car up on my lift and after changing the oil and filter I started it up to check for leaks and that is when I felt it at a specific RPM. In the past I was not able to isolate it.

My engine has been very smooth throughout the entire RPM range up until a couple of months ago so it is not a design condition.

How hard is it to change the front engine mount?

blue2000s

It's not bad. Pedro's garage has a pretty good tutorial.

highlow

I have the same vibration around 3k. From the amount of people who have it, it seems to be normal.