LuckyP

Hi all,

I love my 964. Bought it three years ago just for the looks really, as I felt it was the quintisential 911 ICON shape. But then I drove it.

What a life changing experience.

I ditched my company car, and used the C2 as my daily hack for the last 2 years, never missing a beat. With Billy HD dampers, H&R greens and ARBs it's just compliant enough to get you to work and back with a grin, but still hard enough to hold you on a steady course around Goodwood or Snetterton showing the RSs that they don't have it all their own way!!

But.....

Since the last full service (with valve clearances done) and another blast around Goodwood (bouncing off the limiter), she's developed an engine noise. There from cold (and no change to hot) between 3000 and 4000 RPM, it sometime whirrs in a harmonic kinda beat witha clackety-clack that I can only equate to a badly adjusted push bike derailleur on the flat under constant cadence.

Edited to add - here is the sound:

http://vimeo.com/13917263

I know I've not been very graphic, but do any of you technical wizards have any idea what I'm describing?

Most greatful.

Pete.

Shamus964

Couple of questions - does it present itself with the clutch engaged and/or disengaged, rolling vs. stopped? Also, do you have a lightweight flywheel installed?

Rocket Rob

Do you have access to a lift or jack stands? I would be tempted to lift the car up, start the engine and try to narrow down where the noise is coming from. Have you checked all of your fluid levels? I low power steering fluid will make some bizarre noises. Or maybe its a loose heat shield that wasn't completely tightened after the valve adjustment.

LuckyP

Shamus, I can't replicate it when stationary at all, at any RPM. It won't happen under load either. No lightweight flywheel AFAIK. I've not tried with the clutch engaged at speed, but it's onlly through those RPM of 3-4000.

Thanks for responding. It's doin' my nut in!!

LuckyP

Rob,cheers.

I do. Yes. I will try. What you mean with the wheels at speed? I'll check PS fluid tomorrow.

Sorry to start a thread and break away, but my folks have just reminded me I'm due for roast lamb at theirs. Back in a couple of hours.

gchristofi

Can't help thinking, having heard your description, this might be from a chain/chain tesnioner prob? Maybe one of those 'mechanics stethoscope' whatsits would help locate the problem more closely?

LuckyP

Hi all back again. Do you know, I did use a stethascope the other night (whilst ststic of course) onlt on the lhs bank and there was defo a louder tapping to the right bank.

I've uploaded the video and have even noted the times when the noise is prominant, but I think you guys will hear it for yourselves. I just have to sit in a dark room, in a ball, rocking for a moment, whilst I come to terms with the fact that my octagenarian folks can't get to grips with the preset function on their radio on their bedside table. Every time I go round there they've reset all 6 presets to the same channel - by depressing the buttons that bit too long. Either I've lost the ability to explain what they are doing or they've lost it. I'll go with my fault for the moment and ignore the obvious!!


Here it is:

http://vimeo.com/13917263

boxsey911

To my ears it sounds like it's coming from the exhaust. Could be internal (loose baffles) or a shield on the car or even a loose bolt (not tightened up properly when they removed the exhaust for the valve adjust).

LuckyP

Hi Steve, I don't want to get my hopes up yet that it could be 'just' that. Although I might have a peeky at exhaust upgrades.

But why the 'whirry-whirry, whaarro-wharro'? (for want of real english!!)

boxsey911

It was only in the engine bay part of the video that I could really hear the noise. To me it sounded like something suddenly started to resonate...just like when aftermarket exhausts produce a drone at a certain rev range...speed up and it goes...slow down and it goes...get it in the right rev range and it's annoying.

Just my thoughts on hearing the noise once but don't worry our American friends will be home from work soon and I'm sure you'll get lots more input by the morning

LuckyP

OK Steve,

I'll turn off the lights and keep rocking.........

LuckyP

The noises are most prominant at:

8secs, 39secs, 52secs, 1.01min, 1.10min, 2.14min, 3.20min, 3.28min, 4.28min, 4.40min, 5.30min, 6.00, 6.12min, 6.22min, 6.50min........approx......

boxsey911

Is the noise there if you adjust the temp dial on the CCU - I'm guessing you're on full cold at the moment (blue dot)?

jevvy964

Hi Pete

Couple of ideas....

Exhaust/heat exchanges as has already been said - have you tried to rattle the HE covers?
Alt /fan bearings kaput?
Alt air diverter thingys come lose? (hard to see without pulling the alt)
Engine tin come lose?
Clutch failing (can you peek through the inspection holes looking for debris)
Rocker/tappet issue (worth pulling the covers for a quick check?)

Hope its something simple.

LuckyP

Sorry chaps been away for a couple of days.

Thanks for the comments. I'll check those things out.

The more I hear it the more it sound 'chainy'.

I'll report back.

Pete