Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > Porsche 911 Technical Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered
 
techweenie's Avatar
 
Join Date: Jul 2000
Location: West L.A.
Posts: 21,037
Garage
What's causing this "thunk"?

I have a 'thunk' when turning moderate to hard corners. It's coming from the rear of the car. (72T MFI Sporto)

It doesn't sound quite like a broken sway bar mount -- which is the typical cause of such sounds -- and it's further ruled out by the fact there's no rear sway bar(!)

I can feel the thunk in the chassis, so it's not just a shock dust cover or anything insubstantial. It's as if there was something weighing several pounds sliding across inside the engine compartment -- but I can't see anything that would work that way. I'm selling the car and want any issues taken care of.

Suggestions?

__________________
techweenie | techweenie.com
Marketing Consultant (expensive!)
1969 coupe hot rod
2016 Tesla Model S dd/parts fetcher
Old 03-15-2004, 08:33 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered
 
Join Date: Oct 2001
Location: San Carlos, CA US
Posts: 5,529
CV joints?
__________________
Porsche 2005 GT3, 2006 997S with bore-scoring
Exotic: Ferrari F360F1 TDF, Ferrari 328 GTS
Disposable Car: BMW 530xiT, 2008 Mini Cooper S
Two-wheel art: Ducati 907IE, Ducati 851
Old 03-15-2004, 09:19 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered
 
avendlerdp's Avatar
 
Join Date: Aug 2000
Location: Glendale, Ca. USA
Posts: 756
Garage
My 70t does the same thing. I think it's spring plate bushings. I'm switching to neatrix anyway so I'll soon find out. Anyone??

Alex
__________________
1972 Porsche 914 Project
2000 BMW M5
1973 Aermacchi 350
Old 03-15-2004, 09:24 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered
 
Join Date: Mar 2001
Location: Geosynchronous orbit over Boulder, CO, USA
Posts: 1,087
Garage
shock bushings can feel snug to the touch but have enough slack to thunk under driving loads.
__________________
Charlie Baer
'79 Euro 911SC (Guards Red)
'83 Quattro (Mars Red)
Old 03-15-2004, 01:40 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered
 
dfw911's Avatar
 
Join Date: Aug 2003
Location: Wichita Falls, TX
Posts: 113
Is it a repetitive noise or does it just "Thunk" once in each turn
__________________
Bart
'72 targa 2.7
Old 03-15-2004, 02:51 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered
 
avendlerdp's Avatar
 
Join Date: Aug 2000
Location: Glendale, Ca. USA
Posts: 756
Garage
One thunk per turn. Only on hard turns.
__________________
1972 Porsche 914 Project
2000 BMW M5
1973 Aermacchi 350
Old 03-15-2004, 06:00 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Registered
 
H.G.P.'s Avatar
 
Join Date: Apr 2002
Posts: 1,492
Quote:
Originally posted by thabaer
shock bushings can feel snug to the touch but have enough slack to thunk under driving loads.
How does one go about diagnosing? Is the slack evident upon basic inspection?

Also, will this symptom occur repetitively, per each wheel cycle, while driving?
__________________
1969 911 E Coupe
"Little Bull" "Horse"
"H." Heart, "G." Gears, and "P" the Porsche
Old 03-15-2004, 06:13 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered
 
techweenie's Avatar
 
Join Date: Jul 2000
Location: West L.A.
Posts: 21,037
Garage
I'm going to have to codify the thunk with some careful observation over the next couple of days.

Thanks for all the input!
__________________
techweenie | techweenie.com
Marketing Consultant (expensive!)
1969 coupe hot rod
2016 Tesla Model S dd/parts fetcher
Old 03-15-2004, 10:01 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered
 
IROC's Avatar
 
Join Date: Jan 2003
Location: Knoxville, TN
Posts: 11,476
Garage
I had a thunk like this once and after searching forever it turned out to be one of my shocks was toast. It was a Koni red shock and it had almost no resistance to movement when I removed it (and it was only about a year old - Koni obviously replaced it for free).

Something to check.

Mike

__________________
Mike
1976 Euro 911
3.2 w/10.3 compression & SSIs
22/29 torsions, 22/22 adjustable sways, Carrera brakes
Old 03-16-2004, 03:40 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Reply


 


All times are GMT -8. The time now is 09:23 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.