Extreme camshaft deviation

[Alex]

I do have a Dansk sports silencer (no valve), !

I bet you're flexis have probably split on them. Common fault with the DANSK. Shame as they're a decent sounding box.

Here's mine:




Mine started off with a fluffy tone and then progressed on to this:





I once had a loose coilpack which also caused the exhaust note to sound fluffy too.

 

[WG]

Interesting ideas, I honestly hadn't even considered exhaust as a possibility, considering all the other factors previously mentioned. Will look into those as well, thanks!

 

[deMort]

First off .. check for an exhaust blow .. yeah i know it's unlikely but that noise does sound to me like an exhaust blow and possibly around a lambda sensor .. that if it is that would explain the high injector duration .

Rule this out first please before moving on .

 

[The Baron3]

I had a very similar noise on my Boxster, it turned out to be gasket joining the manifold to the back box, easy fix and quite easy to diagnose if you can get under the car, I do think it's exhaust related.

 

[WG]

I've checked the exhaust and everything looks alright to me, except rusty manifolds that I anyway wanted to replace at some point (but haven't dared to touch the bolts).

It seems that the noise is coming from that area, just find it strange that it doesn't sound like a blowing exhaust, that it only happens when warm, and just at the final point when the clutch bites?? I also tried to lift the car and the noise was much fainter with the wheels in the air.

Was hoping to the leave the manifold alone for as long as possible due to all the horror stories. I don't have any experience with drilling out bolts, but could rent a Stomski kit.

Is there a way to verify that the manifold(s) are the source of the noise? Or if it's just a simple gasket as The Baron suggests, how can I identify that?

 

[barryrs]

Your manifold looks mint :lol:

Mine was showing extreme cam deviation a couple of weeks ago and having read on a US forum that it was solved with new coil packs I decided to give this a try. My car came with a fully stamped service book but few receipts to prove work previously completed.

New plugs and coil packs fitted and it's running 100 times better with just a very slight misfire; however, I now know I also have an AOS issue to sort.

5 coil packs came out looking okay but one had different markings and looked like this!!!

[img]https://thumbsnap.com/s/8Wja4Kof.jpg[/img]|https://thumbsnap.com/8Wja4Kof

 

[Alex]

I've seen much worse manifold bolts. There's a chance they might wind out.

If the manifold gasket is blowing a bit you can usually see a patch of black soot where it is. Couls possibly be the manifold to cat gasket blowing. You can feel the fumes puffing out from the joint if it is that.

 

[WG]

Your manifold looks mint :lol:

Mine was showing extreme cam deviation a couple of weeks ago and having read on a US forum that it was solved with new coil packs I decided to give this a try. My car came with a fully stamped service book but few receipts to prove work previously completed.

New plugs and coil packs fitted and it's running 100 times better with just a very slight misfire; however, I now know I also have an AOS issue to sort.

Haha, maybe I'm just looking for an excuse to fit some new shiny ones.
I actually have a set of new coil packs, will get around to fitting them now. Thanks for the tip!

 

[WG]

I've seen much worse manifold bolts. There's a chance they might wind out.

If the manifold gasket is blowing a bit you can usually see a patch of black soot where it is. Couls possibly be the manifold to cat gasket blowing. You can feel the fumes puffing out from the joint if it is that.

So obvious, why didn't I think of that earlier today!

 

[WG]

So obvious, why didn't I think of that earlier today!

The problem is that the noise is mostly present when the car is moving, so I can't feel for leaks. I'll have another look for any soot, but otherwise I just have to start replacing parts and hope for the best.

 

[IMSF8]

My 2006 Cayman S has been displaying similar (and worsening) symptoms since the engine was rebuilt. These include:

• Ticks at idle but only when the clutch is depressed
• Doesn't tick when cold. Ticking begins after a few minutes of warm up.
• Ticks irregularly at the cam/IMS rate, NOT the crankshaft rate
• Ticking isn't easy to localize but it seems like it's coming from the heads, not the transmission
• Ticking is irregular ... worse sometimes than others

I originally thought this was a flywheel/clutch problem but the ticking frequency, character of the sound and the apparent point of origin are wrong. I subsequently checked the crank end play and it was within spec. I was wondering how the else clutch position might affect the engine when I thought of the variocam system and subsequently read you posting.

Have you considered bypassing the clutch position sensor to see if it affects the noise? Some would argue the engine is better off without it because of the crank thrust bearing loads at startup with the clutch depressed.