engine seems to sound 'different'

I just noticed a sort of 'whirring' sound when driving under load. Almost like the sound of an electric motor, mixed in with my normal engine sound. What could it be? The tires aren't down to the wear bars, and nothing is rubbing anywhere. Could it be bearings somewhere, or the warning sign of transmission trouble? The car drives fine otherwise.

Electric fans.........................

Pinion? Is it relative to speed? I've seen a 996 w/a bad pinion and as speed increases so does the whine. It's not very load at all, sort of barely noticeable about tire noise. -KJ

No, it disappears when stopped.

That might be it, but what do you mean by 'pinion'?

Fuel pump?From the front of car? Regards. Mike

No, it's coming from the rear. It almost sounds like something rubbing on the tire (like those old generators you had on old bicycles to light up the front lamp).

Look on the inside tread of the rear tires it wears down first and will make noise.

That was the first thing I checked, but it doesn't apply here since the noise only happens under load.

The pinion is a major gear in your differential. In super simplistic terms (because that's all i know. :-p) it transfers the power from the tranny to the driveshaft. Evidently it can be driven for a while and will simply get noisier and noisier but it will eventually fail. I'm not sure if you'll need a new tranny. I think I've seen in Excellence or Pano that guard transmissions now makes pinions for the 996 gear box. Good luck. I hope it's not your ring and pinion. Let me know how this shakes out. -KJ

Thanks for the info. I'll get it looked at next time I'm in for service, which should be in a couple of weeks.

Took it in for service today and found out that the noise was coming from the water pump and also the belt tensioner. I'm having both replaced under warranty next week.

Good deal. Glad it was nothing major! -KJ

damn...i've been hearing a whine intermitently all this year. KJinDC, did you car throw any CEL's at you when u heard this? or was it just the noise?

My noise started last week, and it is gradually getting more noticeable. I'm hoping to have the parts replaced this week.

^ what is cost of this repair?

I'll let you know once it's done.

i had the same thing, noise coming from buttom on the car, evne worse when the car is warmming up. and water pump broke in front of my house. thank god i wasn't going to work that day.

How much time had elapsed from when you first started hearing the noise to when the pump failed?

about 3 month. it gets louder and louder. the guy in my garage say to me:"your car sounds like mustung those days"

Total cost was about $1,150, of which my warranty covered $950. This included the water pump, belt tensioners, and some related stuff.

to paul marangoni, I have a similar whine like noise. Ive had the noise since i bought the car 9 months ago. the noise increases with higher speeds. I didnt think it was a problem because it is my first porsche and thought these were regular sounds made by the car. I was just wondering if you had any coolant level issues (lower than normal) or higher than normal coolant temperature readings via the dash gauge. I ask because I am currently trying to resolve this exact issue with my car. I am wodering if my water pump is starting to go bad and is resulting in higher than normal operating temps. Thanx, Peter

I would take it in to a mechanic to have it checked out if I were you. I was afraid it was my transmission, as the noise only happened when under load. I just mentioned the noise to my mechanic and they located the problem right away: Faulty water pump, accessory belt tensioner and both idler pulleys. I had no issues with temp or coolant level. It was just a noise that appeared out of nowhere. Your noise may be something else entirely.