3.0L SC engine typical noises

[tyro]

I've been meaning to post for a while..

What makes that whirring or turbine sound in these cars? I notice it more in some than others. I hear it in mine, heard it louder in another earlier car and was curious.

Thinking the noise comes from the fan, I d/c'd the fan belt as a test. Don't recall much difference.

Is it chains? Being the nutty DIY-er that I am, I can't help but think that there might be something wrong.

It sounds like straight-cut gears in a transmission if I could describe it; isn't there a straight-cut gear between the crank and intermediate shaft?

Cheers

[emac]

Jess
I have a 81 SC and notice the sound you mention at higher RPM. Must admit I love it. Had my car for about 12 years now and she runs like a deer. I really dont think anything is wrong just the nature of the beast.

Enjoy

[juanbenae]

you need louder exhaust

[mr 911]

^^ what he said

[mickey356]

I have an 83SC with an M&K and I can't hear a thing other than the exhaust, it's AWESOME!!

[grudk]

Whirring? I hear a kind of undulating/harmonic sound when cruising at freeway speed, approx two second cycle (78 ROW motor)... figured it was the oil pump. No problems noted

[Alan Lindquist]

Every two years I put the Catalytic converter back on for smog. Normally I run a J-Pipe with a Dansk stainless steel exhaust with 84mm outlet. it's loud but I like the sound when you get on it. With the J-Pipe I hear that high pitch sound. With the Cat on the car, that high pitch sound is not there. I have a "old school" mechanic who tunes it for smog and gets it to pass then re-tunes it for the street. He commented that he like the sound of his Porsche with the Cat because he doesn't get that high pitch sound. I know what you're talking about - it sounds like the transmission. But for my 80SC, it's the exhaust.

Interesting comment on the response above about the undulating/harmonic sound. I get that too and imagined that the wear of a 200K motor was showing up. And I have a #2 cyl that is going along for the ride - not much compression. I haven't determined what causes that sound, but the engine keeps running.....

[tyro]

I've tried a "less-quiet" muffler, but the drone on the highway got a little old.

Switched to a stock-ish sport muffler and can still manage to upset the neighbors.

Listed in this recent thread is this video where the noise is obvious (it's the whining or whirring sound when the throttle is opened a bit):

[tyro]

Any thoughts as to what creates most of the angry vacuum cleaner sound?

Fan: not much

Chains?

Straight-cut gear?

Cheers,

[GothingNC]

I have the same sound on my SC.

SSI's with Dansk Sport Muffler, took a little while to get used to the "whine" so I stay above 3000 RPM.

[rogwilson]

Jess,
Any luck in diagnosing that whirring sound? I have 1500 miles on my topend rebuilt motor and now my engine sounds like the video. I do not remember the whirring sound being so prominent before the rebuild.

I thought maybe the alternator bearing was giving out but the sound is the same with the belt off. I replaced the chains during the rebuild. Maybe that has something to do with it. I may have to pull the cam covers and check it out. I also but in a clutch kit. Now, I wonder if I greased all the components properly. But the sound is the same in gear and out, clutch engaged and disengaged. The sound seems to come from the engine bay. It has me baffled.

I used a auto stethoscope all over the engine and I can not pinpoint where the sound originates.

You are right, there are a number of videos on the internet that definitely have the same turbine whirring sound like your posted example. Maybe that is a normal sound of the engine. If you or anyone has explanation it would be great to know.
roger

[SCWDP911]

Originally Posted by tyro

Any thoughts as to what creates most of the angry vacuum cleaner sound?

Fan: not much

Chains?

Straight-cut gear?

Cheers,

I have the whiiring noise, but I also have always thought mine sounds like an old sewing machine that is a bit angry... so what makes it sound like an old Singer?

[James Brown]

It's a little bit of everything, like a blender full of open end wrenches on frappe! Fan, cams, chains, valve lash, oil pump, exhaust, alternator, gears. They all blend there notes together to form a P-O-R-S-C-H-E.
You can isolate a sound with one of them stethoscopes or a long screwdriver held up to your ear. You can hear all kind of sounds-most normal.

[psalt]

It is the ghost of Hans Ledwinka, screaming for his stolen ideas, all of which make a Porsche a Porsche (rear engine, horizontal opposed cylinders, force duct fan air cooling, torsion bar suspension, swing axles, back bone chassis, etc ). You cannot remove it because justice must be served.

[Daviboy]

Thats normal for my engine when it is running

[mike635]

I posted a similar question about a month ago and didn't get an answer. I'd post am link but then tread went into a silly direction.

I bought my SC from my brother who had the pressure fed chain tensioner installed. He insists that the whine came along with the new tensioners. Althought it is a diffent engine, I have another family member with an 89 Carrera and it sounds quite different, no whine and much deeper exhaust tone (stock exhaust). Both sound great to me.

Mike

[easelboy1]

I don't remember an undulating sound - but always had that nice air sucking sound from the airbox when I lay into the throttle - definitely a sound I miss now that I am running a 3.2...

[Aurel]

With the cat installed and the Targa top closed, I distinctly heard a whine from the fan at low rpms in fith gear. It sounded a bit like a turbo, I liked it. Now with SSIs, the sound is covered by the slightly louder muffler. Anyway, this is a normal sound.

PS. Tyr, on your video, the fan belt seems a bit loose.

[tyro]

Originally Posted by Aurel

PS. Tyr, on your video, the fan belt seems a bit loose.

Thanks, but that's another member's car.


Anyway, I just thought someone may have an idea as to what makes that distinct vacuum sound. The sound seems to emanate from the timing chain area closest to the crank.

Sure it's normal, but where does that sound come from?

[glewis80SC]

Sounds just like my 80SC, it sounds like a Porsche to me.