Knocking from behind driver (RHD)...

Christian S. · 08-06-2009, 07:31 AM

I wonder if anyone has had a similar knocking/rattle experience to this and could advise? Picked up an early 05 Boxster a month ago and proceeded to drive 3281 miles around France with it. Great fun and very happy with the car.

However on returning to the UK the car has started to develop a variable knocking sound that seems to be coming from behind the driver's seat (RHD). At first I thought it might be something loose in the door, but it has become louder and seems more rearward. It's a variable knock, that can be generated by poor surfaces, but does not seem directly linked to the suspension. It's also fairly low frequency and becomes less distinct when speed rises (due to overall noise).

It seems to be there regardless of the hood being up or down - although inevitable with the hood down, there's more general noise.

I'm about to attempt entry into the innards of the engine to see if anything has worked loose, but superficially, everything seems secure.

cviles · 08-06-2009, 10:21 AM

It could be one of the control arms on the rear suspension. The bushings get worn and need to be replaced periodically. I had a similar noise on my '05 and the dealer replaced the arm under warranty and fixed the noise, so I can't give you an estimate of cost if that's the problem you have.

Christian S. · 08-07-2009, 06:38 AM

Thanks cviles - I'll get it up on the jacks and have a look at that - maybe swap both sides out while we're there.

berty987 · 08-21-2009, 05:15 AM

Does the car have the optional PASM ? The shocks can be prone to wear giving this noise.

Christian S. · 08-24-2009, 04:05 PM

Quote:

Originally Posted by berty987

Does the car have the optional PASM ? The shocks can be prone to wear giving this noise.

No, it's standard I'm afraid. Interesting though, as the sound has got steadily worse and is a constant feature now - sounding more "spring like" ie. a tension sound - I wonder whether the top mounts are prone to wear?

litteng · 10-06-2009, 06:00 PM

i assume from you posting that you have a 987 model, but you state no information regarding mileage.

there is a tech bulletin issued regard a piston knocking which occcurs in the oil pump.

my car was doing as it was warming up and rev's were between 2 - 3000 rpm.

dealer repair under warranty in my case, problem banished

check to identify when it occurs, then talk to the dealer...

Christian S. · 10-06-2009, 06:08 PM

Quote:

Originally Posted by litteng

i assume from you posting that you have a 987 model, but you state no information regarding mileage.

As stated in my original post, it's an early 05 model - 987. Mileage is 40,000 , however it has spent most of it's life in Edinburgh, in the New Town where the streets are still cobbled. Definitely a suspension related issue - happening regardless of rev range.

I'm about to take it to an independent shop, hopefully they will be able to diagnose and repair it using experience, rather than my guesswork! Thank you for the suggestion nonetheless.

ricster · 10-06-2009, 06:41 PM

My guess its the intermediate shaft about to go south

tinman · 10-11-2009, 07:49 PM

what would the IM shaft repair cost in USD$, and can you give some background about, how, when, why.....

thank you
______________________

Howard L.

08-06-2009, 07:31 AM	#1
Christian S. Addict Rennlist Lifetime Member Join Date: Jun 2001 Location: Scotland Posts: 359	Knocking from behind driver (RHD)... I wonder if anyone has had a similar knocking/rattle experience to this and could advise? Picked up an early 05 Boxster a month ago and proceeded to drive 3281 miles around France with it. Great fun and very happy with the car. However on returning to the UK the car has started to develop a variable knocking sound that seems to be coming from behind the driver's seat (RHD). At first I thought it might be something loose in the door, but it has become louder and seems more rearward. It's a variable knock, that can be generated by poor surfaces, but does not seem directly linked to the suspension. It's also fairly low frequency and becomes less distinct when speed rises (due to overall noise). It seems to be there regardless of the hood being up or down - although inevitable with the hood down, there's more general noise. I'm about to attempt entry into the innards of the engine to see if anything has worked loose, but superficially, everything seems secure.

08-06-2009, 10:21 AM	#2
cviles Addict Rennlist Member Join Date: Aug 2006 Location: Houston, TX Posts: 993	It could be one of the control arms on the rear suspension. The bushings get worn and need to be replaced periodically. I had a similar noise on my '05 and the dealer replaced the arm under warranty and fixed the noise, so I can't give you an estimate of cost if that's the problem you have. __________________ Chris '07 Carrera S (Raawwwwrrrr) '05 Boxster S (There is no substitute) '04 BMW M3 (Now all my keys go into the left side...) '02 BMW M3 (If you ever wanted to cut balsa wood with a chainsaw...) 95 BMW M3 (Still miss the telepathic steering) 93 MR2 Turbo (RIP - The wall wasn't kind to Mr. Two)

08-07-2009, 06:38 AM	#3
Christian S. Addict Rennlist Lifetime Member Join Date: Jun 2001 Location: Scotland Posts: 359	Thanks cviles - I'll get it up on the jacks and have a look at that - maybe swap both sides out while we're there. __________________ Christian S.

10-06-2009, 06:00 PM	#6
litteng User Join Date: Jun 2008 Location: s'toon SK cdn Posts: 12	possible known problem i assume from you posting that you have a 987 model, but you state no information regarding mileage. there is a tech bulletin issued regard a piston knocking which occcurs in the oil pump. my car was doing as it was warming up and rev's were between 2 - 3000 rpm. dealer repair under warranty in my case, problem banished check to identify when it occurs, then talk to the dealer...

08-21-2009, 05:15 AM	#4
berty987 User Join Date: Dec 2007 Posts: 7	Does the car have the optional PASM ? The shocks can be prone to wear giving this noise.

10-06-2009, 06:41 PM	#8
ricster Addict Rennlist Member Join Date: Apr 2009 Posts: 403	My guess its the intermediate shaft about to go south

10-11-2009, 07:49 PM	#9
tinman Addict Rennlist Member Join Date: Jan 2006 Location: Southern California-Thank You!!! Posts: 91	what would the IM shaft repair cost in USD$, and can you give some background about, how, when, why..... thank you ______________________ Howard L.