Odd Boxster Sound?

[JCL12]

Can anybody identify a potential source of this sound? Description:

-Car is 2001 tip box
-Appears to come from behind me on the left side (driver side)
-Sounds like a very slight rattle or something is loose and gently vibrating or grinding
-Sound volume is very low - I cannot hear it at all if I have the crummy radio at even a moderate volume
-Only happens when the car is not warmed up (If I'm at 180, I'll never hear it)
-Only happens at low RPM (<1600)
-Seems to only happen in 4 and 5th gear (and maybe 3rd)

I assume this is nothing, but I am curious!

[Paul]

Why are you driving your car in those gears at less than 1600 rpms!!

[Adam]

Originally Posted by Paul

Why are you driving your car in those gears at less than 1600 rpms!!

He must have skipped that page in the manuel that says don't lug the engine under 1,500 rpm! I see people on here all the time saying they do this Maybe it's a gas mileage thing.

[JCL12]

Originally Posted by Adam

He must have skipped that page in the manuel that says don't lug the engine under 1,500 rpm! I see people on here all the time saying they do this Maybe it's a gas mileage thing.

The automatic transmission will sometimes shift me to a higher gear and put me at sub 1600 RPM land.

[Adam]

Originally Posted by JCL12

The automatic transmission will sometimes shift me to a higher gear and put me at sub 1600 RPM land.

That's kind of odd. Porsche says don't lug the engine and that's exactly what the auto tranny does sometimes? I thought that tip transmission was supposed to be smarter than the average guy.

[JCL12]

Adam,

If I am accerelating very slowly, the auto shift points will sometimes come too early.

BTW - Why would there be an issue with running the engine in sub 1500 RPM range? Idle is sub 1K, starting in 1st or 2nd spends a lot of time <1500RPM. I dont get it!

[Adam]

Originally Posted by JCL12

Adam,

If I am accerelating very slowly, the auto shift points will sometimes come too early.

BTW - Why would there be an issue with running the engine in sub 1500 RPM range? Idle is sub 1K, starting in 1st or 2nd spends a lot of time <1500RPM. I dont get it!

It's ok to spend some time under 1,500 rpm...we all have to do that like when taking off or going around a curve, but you don't want to spend an excessive amount of time there. What Porsche says not to do is lug the engine. Meaning don't drive it 40mph in 5th or 6th gear for example. There is very little load on the engine at idle so that would not apply. I'm not sure why exactly Porsche says to avoid this, maybe someone else on here can shed some light on it.