jakal121

Hi All!

New to the forum - trying to get to the bottom of a problem that is irritating the life out of me!

I'm exhibiting a tapping/knocking sound when accelerating - very noticeable in lower gears after the car has warmed up (not present when cold) - the sound disappears immediately when the clutch is pressed and my foot is off the accelerator.

The sound of the tapping/knocking is always equally paced and progressively speeds up with acceleration. It fades/disappears completely at higher speeds.

Hard to hear when windows are down, but extremely noticeable around 2000rpm with windows up in the cabin.

To summarise:

- No tapping/knocking while idle/in neutral
- Sound is equally spaced and gets faster with acceleration then fades
- Most noticeable around 2000rpm in lower gears (1, 2, 3)
- Almost completely disappears above 3000rpm
- Sound disappears when clutch is pressed even while rolling at any speed
- Only present when the car is warmed up
- Louder when car has warmed up completely
- Not present when cold but slowly gets louder as car warms up
- Serviced around 1500 miles back

If anyone can help narrow down what could be causing this I will be extremely grateful.

Local indy took it for a spin and told me he couldn't hear anything out of the ordinary.

I've since taken another 987-1 for a drive which doesn't have a trace of the sound im hearing in mine

Macster

Having a hard time reconciling your report regarding the noise and the indy reporting not hearing anything out of the ordinary.

Giving you the benefit of the doubt my WAG is it reads like it is drivetrain possibly even clutch related.

There is not much you can do without expensive labor to if it comes to this removing the transmission.

Before one goes this far he wants to be sure that's where the problem lies. A high confidence diagnosis is necessary then and since your indy didn't hear anything out of the ordinary (and giving him no benefit of the doubt) you need to find another place to take the car and demo the noise or ride along and coach the technician how to reproduce the noise.

jakal121

Thank you for the response Macster!

I'll most likely be visiting a different place to see if they can hear the sound i'm hearing

Just wanted to get the feelers out there to see if others may have come across anything similar with their 987

JCtx

I have a good feeling you're talking about THIS noise:


Many of our new 981s are doing it at exactly the rpm range you mentioned. On my car I can only hear it like you (rolliing in 1st, 2nd and 3rd, between 2 to 2.8K rpm with my window open). As soon as I ease a millimeter from the throttle, noise goes away, even at the same rpm range. When I press the gas again to stop decelerating and maintain speed once again, comes right back. Funny my car doesn't do it stationary (at least not yet). Does yours? This next one is a bit more severe, since you can hear some banging even at idle:


And this last one is the most severe of all, with an even louder banging, and at idle as well. But it's doing it intermittently, so no dealer has done anything about it:


Here's the current discussion about this issue: http://www.planet-9.com/981-cayman-a...ing-noise.html. We're trying to determine if the second and third videos above are a progression of the rapid ticking on the first one, which many of us have, but like you pointed out too, not all cars make it. But if your 987 makes the same noise, there's some hope whatever the heck is making it (happens on both PDKs and manuals), it's considered 'normal'. The guy from the second video just got his car back from a dealer which changed all lifters, and no change. Let me know if this is your noise. Take care.

endrehu

I have exactly what you describe here. Did you ever find out what caused this noice?

hueyhoolihan

pretty much the same deal here on a 2007 987 2.7L. if i open my oil filler cap, i can REALLY hear it...

...and i don't like it.

crowell33

Did you ever come to a conclusion? I have an '08 Base with the same symptoms. I've changed the oil twice in the past 8 months, and the PPI got a clean bill of health from Koala Motorsport here in Ohio. I've also taken it on a road trip from Cleveland to Nashville, and two more from Cleveland to D.C. with no issues at all. It's driving my crazy, though.

RandyL

Just stumbled upon this thread. I have a new-to-me 2006 987.1 and noticed a somewhat subdued knocking under similar conditions as the OP: range is 2,000-2,800, warm only, throttle load doesn't change it, no sign of it any any other rpm range. Of course once you notice it you're sensitized to it and convinced it's going to throw a rod any day now. Any other info on this surface?

Derbish

Randy,

Did you ever get more info on this? i have the exact same issue on my 08 987.1 with 27kmi. I think its always been there since new, but getting a little loader with age, not sure. I read somewhere that all these engines have some resonance chatter at certian rpms. also read it may mean the timing chain tensioners may need to be replaced.

-Mike.