Welcome to 911UK
The only place for Porsche, 911uk is the definitive enthusiast and resource site for the Porsche 911.
Registration is fast, simple and absolutely free, so join up today for full access to the site and benefit from latest member offers.

Porsche Classifieds
Porsche Buyers Guides
Sell Your Porsche on 911uk
Create a Free Classified Advert
Search Ads
Classified Adverts FAQ
Trade Classified Information
Buyer & Seller Fraud Protection
Consumer Rights Act
Pre Purchase Inspection (PPI)
Porsche Car Sourcing
Porsche Cars Wanted
Official Porsche Centre Reviews
Model
Stock
Porsche 911
991 : 2011- 19
997 : 2004- 91
996 : 1997-2005 44
993 : 1993-1998 5
964 : 1989-1993 2
Carrera 3.2 : 1983-1989 0
Carrera SC : 1977-1983 2
930 Turbo : 1975-1989 0
Early 911 : 1964-1977 3
Porsche Other Models
Classic : 1950-1965 0
Boxster : 1997- 14
Cayman : 2005- 16
Cayenne : 2003- 8
Macan : 2014- 0
Panamera : 2009- 1
912-914-924-928-944-968 1
959 - CarreraGT - RaceCar 1
Car Parts For Sale & Wanted
Other Items For Sale & Wanted
Wheels Tyres For Sale & Wanted
Number Plates For Sale Wanted

Porsche Services
Porsche Body Shop Repair
Paint Protection & Wrapping
Porsche Classic Insurance
Porsche Classic Parts
Porsche Classic Restoration
Porsche Design Collection
Porsche Engine Gearbox Rebuild
Porsche Heritage & History
Porsche News
Porsche Picture Gallery
Win a New Porsche 911

Porsche Parts
Body Parts, Body Styling
Brakes, Clearance
Electrical, Exhausts
Engine Cooling, Engine Electrical
Engine Rebuild, Heating Cooling
Interior Incar, Lighting
Rubber Seals, Service Parts
Steering, Suspension
Transmission, Workshop Tools
Early 911, 911 - 930, 928 - 968
964 - 993, 996 - 997, Boxster
Cayman, Cayenne, Panamera

Porsche Model Range
911 [991] 2011-Current
Porsche 911 [991]
911 [997] 2004-Current
Porsche 911 [997]
911 [GT] GT1-GT2-GT3
Porsche 911 [GT]
911 [996] 1997-2005
Porsche 911 [996]
911 [993] 1993-1998
Porsche 911 [993]
911 [RS] RS-RSR
Porsche 911 [RS]
911 [964] 1989-1993
Porsche 911 [964]
911 3.2 1983-1989
Porsche 911 3.2 Carrera
911 SC 1977-1983
Porsche 911 SC
911 [Early] 1964-1977
Porsche 911 [Early]
Boxster & Cayman
Porsche Boxster & Cayman
Cayenne & Panamera
Porsche Cayenne & Panamera

911uk Site Partners

Post new topic   Reply to topic
Author Message
toddy2
Spa-Francorchamps


Joined: 11 Jan 2015
Posts: 273
Location: Dorset


PostPosted: Mon Nov 12, 2018 5:06 pm    Post subject: Car sounds lumpy - Advice please... Reply with quote

Hi All,

Picked up my car at the weekend after having a full new exhaust including 200 cell cat.

Only driven it home 40 odd cross country miles, it drove and sounded like a dream, very addictive.

Not driven it again until today and it just sounded lumpy, best way to describe it, it sounds like an old VW beetle, and feels sluggish. Had to drive it on a 200 mile cross country trip to plenty of places to open it up and warm up. Occasionally it sounded good, but largely just lumpy.

It sounds fine on iddle and revving standing.

Before I go back to Topgear, just want to make sure there's nothing else it could be, or something simple I should do. Anyone else experienced this?

Thanks in advance......
_________________
Current Porsche Line up:
1968 911T
2002 996 4s
1988 944

Last edited by toddy2 on Tue Nov 13, 2018 4:46 pm; edited 1 time in total
 
  
View user's profile Send private message
   
Marky911
Kyalami


Joined: 04 Jun 2009
Posts: 1915



PostPosted: Mon Nov 12, 2018 5:39 pm    Post subject: Reply with quote

Does it just sound lumpy or is it lumpy?

If it's misfiring then that's a separate fault affecting the sound.
If it's smooth and firing on all cylinders but just sounds a bit poop, then yep thats the new stuff for you.

After seeing and hearing my mates with all the combos of TG stuff I quickly decided it's not for me. It's ok budget stuff but they just don't put enough effort into tuning the sound.

Their service is good though so I'm sure they'll try some options for you.
Good luck.
Thumb
 
  
View user's profile Send private message
   
toddy2
Spa-Francorchamps


Joined: 11 Jan 2015
Posts: 273
Location: Dorset


PostPosted: Mon Nov 12, 2018 7:10 pm    Post subject: Reply with quote

Marky911 wrote:
Does it just sound lumpy or is it lumpy?

If it's misfiring then that's a separate fault affecting the sound.
If it's smooth and firing on all cylinders but just sounds a bit poop, then yep thats the new stuff for you.

After seeing and hearing my mates with all the combos of TG stuff I quickly decided it's not for me. It's ok budget stuff but they just don't put enough effort into tuning the sound.

Their service is good though so I'm sure they'll try some options for you.
Good luck.
Thumb


Difficult to define, very rarely it's smooth. Sounds lumpy and drives as if there's something restricting it.
_________________
Current Porsche Line up:
1968 911T
2002 996 4s
1988 944
 
  
View user's profile Send private message
   
Robertb
Long Beach


Joined: 01 Sep 2003
Posts: 6718
Location: South Oxfordshire

2002 Porsche 996 Carrera 4S

PostPosted: Mon Nov 12, 2018 7:51 pm    Post subject: Reply with quote

Maybe a coincidental fault, such as Coils? Or maybe the new cats causing the ECU to change the engine settings incorrectly?
_________________
"911- the guilt-free supercar"

Current: 2003 C4S Coupe, seal/black

Ex: '02 C4S Coupe, '96 993 Targa, '88 Carrera Sport Coupe
 
  
View user's profile Send private message Send e-mail
   
deMort
Zolder


Joined: 21 Mar 2015
Posts: 5520
Location: Brighton


PostPosted: Mon Nov 12, 2018 8:03 pm    Post subject: Reply with quote

Perhaps a sound clip would be helpfull ..

Im thinking possible misfire atm to be honest .
_________________
.

My Daughter's Crowdfunding page Here

Mechanic

7pm - 9pm
 
  
View user's profile Send private message
   
kas750
Reims


Joined: 31 Mar 2013
Posts: 4109
Location: Chorley lancashire

2006 Porsche 911

PostPosted: Mon Nov 12, 2018 8:05 pm    Post subject: Reply with quote

Sounds like a coil pack/ coil pack connector could of been disturbed.
 
  
View user's profile Send private message
   
alex yates
Brands Hatch
Brands Hatch


Joined: 06 Mar 2014
Posts: 14463
Location: The Ribble Valley, Lancashire

2000 Porsche 996 Carrera 4

PostPosted: Mon Nov 12, 2018 8:07 pm    Post subject: Reply with quote

kas750 wrote:
Sounds like a coil pack/ coil pack connector could of been disturbed.


yes
_________________
2000 Manual 996 C4 Arctic Silver Convertible


 
  
View user's profile Send private message
   
toddy2
Spa-Francorchamps


Joined: 11 Jan 2015
Posts: 273
Location: Dorset


PostPosted: Mon Nov 12, 2018 8:08 pm    Post subject: Reply with quote

deMort wrote:
Perhaps a sound clip would be helpfull ..

Im thinking possible misfire atm to be honest .


Thanks deMort, I'll try and post one up shortly. I'm taking in to my local mechanic for a few bits, including: window regulator; change over seat belts. I might get him to replace the maf sensor and coil pack.

When the new exhaust was fitted, it had a new lamb sensor could that be it?
_________________
Current Porsche Line up:
1968 911T
2002 996 4s
1988 944
 
  
View user's profile Send private message
   
deMort
Zolder


Joined: 21 Mar 2015
Posts: 5520
Location: Brighton


PostPosted: Mon Nov 12, 2018 8:27 pm    Post subject: Reply with quote

First off .. dont throw parts at the car .. i do hate people doing that .. it costs money !

Its possible the car is actually adapting to the new exhaust ..

Basically the car trys to maintain Lambda on each cyl .. (correct fuel / air ratio ) .. it takes a while to do this when new parts or fault codes have been cleared .

Its basically the car adapting to worn components and is normal .

You need in the region of 50 miles to get sensible adaptions and to know if there is actually a fault .. with a tester then a bit quicker as you can see the engine values and fault codes that might not generate an eml on .

For my part .. and as ive said im not a mod guy then the car will need to adapt and possibly even be mapped to get the best from the exhaust.

Porsche have a set map in the DME for the Set exhaust .. you have changed this so the flow characteristics have changed and may well need a remap to get it correct .. ask Top gear there as this isnt my area of expertise im afraid .. i do standard stuff Smile .

EDIT ..

A new Lambda sensor one side but not the other will often throw up an ageing fault with the one that hasnt been changed .. i always recomend replaceing in pairs .
_________________
.

My Daughter's Crowdfunding page Here

Mechanic

7pm - 9pm
 
  
View user's profile Send private message
   
toddy2
Spa-Francorchamps


Joined: 11 Jan 2015
Posts: 273
Location: Dorset


PostPosted: Mon Nov 12, 2018 9:34 pm    Post subject: Reply with quote

Thanks as always deMort.

It's a mod out of necessity, needed a whole new exhaust and oem prices were crazy.

I've done 250 miles now with no improvement, so will get a diagnostic done. Good idea possibly remap too.
_________________
Current Porsche Line up:
1968 911T
2002 996 4s
1988 944
 
  
View user's profile Send private message
   
FRZ 911
Imola


Joined: 19 Jun 2015
Posts: 864
Location: Northern Ireland

2007 Porsche 997 Carrera 4S

PostPosted: Mon Nov 12, 2018 10:30 pm    Post subject: Reply with quote

+1 on the diagnostic check before going down the remap route. I’ve just had a full system put on my 997.1 C4S and have put over 500 miles on it without any problems. I think kas750’s suggestion is looking pretty likely.

Hope you’re sorted soon and able to get back to enjoying the sound which, imho, is far from ‘poop’.....but each to their own. Thumb
_________________
997.1 C4S Meteor Grey Manual

 
  
View user's profile Send private message
   
Stoo.c
Monza


Joined: 07 Apr 2014
Posts: 191
Location: Hertfordshire


PostPosted: Tue Nov 13, 2018 9:20 am    Post subject: Reply with quote

I had an almost identical problem with my top gear exhaust however it was intermittent which was even more annoying. I was really unhappy with it. Turns out it was blowing in certain circumstances despite me using all of the new gaskets, fittings etc. I replaced all of the gaskets and clamps with new Porsche ones and made sure it was well sealed. Problem solved now - unfortunately at the cost of the Top Gear exhausts, I think it has to be expected that there are certain corners cut.

I'm happy enough with it now. Would I buy it again - probably not but I do however think its fairly good value for money.
_________________
02 996 C4S
93 Skyline R33 GTS-t
91 CRX vtec turbo
01 986 Boxster S
 
  
View user's profile Send private message
   
Martin996RSR
Spa-Francorchamps


Joined: 08 Dec 2016
Posts: 281



PostPosted: Tue Nov 13, 2018 1:27 pm    Post subject: Reply with quote

Can the OP please change the title of this thread to remove the reference to Top Gear? The likelihood of the fault being down to the exhaust is very low indeed. I know, because I have one, and I have a lumpy idle that I'm pretty confident is down to a lazy lifter. There are any number of things it could be on the OP's car and when reading the thread title, people will infer the problem is caued by the exhaust, when it won't be, and Top Gear's good name will have been tarnished unfairly.

By all means change the title back once you've proven the fault lies with the TG exhaust and not your car.
 
  
View user's profile Send private message
   
alex yates
Brands Hatch
Brands Hatch


Joined: 06 Mar 2014
Posts: 14463
Location: The Ribble Valley, Lancashire

2000 Porsche 996 Carrera 4

PostPosted: Tue Nov 13, 2018 1:33 pm    Post subject: Reply with quote

Thumb That's a fair point.
_________________
2000 Manual 996 C4 Arctic Silver Convertible


 
  
View user's profile Send private message
   
toddy2
Spa-Francorchamps


Joined: 11 Jan 2015
Posts: 273
Location: Dorset


PostPosted: Tue Nov 13, 2018 4:47 pm    Post subject: Reply with quote

Martin996RSR wrote:
Can the OP please change the title of this thread to remove the reference to Top Gear? The likelihood of the fault being down to the exhaust is very low indeed. I know, because I have one, and I have a lumpy idle that I'm pretty confident is down to a lazy lifter. There are any number of things it could be on the OP's car and when reading the thread title, people will infer the problem is caued by the exhaust, when it won't be, and Top Gear's good name will have been tarnished unfairly.

By all means change the title back once you've proven the fault lies with the TG exhaust and not your car.


Fair comment, have amended for now until I've had time to investigate....
_________________
Current Porsche Line up:
1968 911T
2002 996 4s
1988 944
 
  
View user's profile Send private message
   
toddy2
Spa-Francorchamps


Joined: 11 Jan 2015
Posts: 273
Location: Dorset


PostPosted: Wed Nov 14, 2018 9:21 pm    Post subject: Reply with quote

Nothing has come up on the diagnostic, I've had the coil packs changed, and mass flow sensor. Still no improvement, I'll try running it more to see if there is any improvement.
_________________
Current Porsche Line up:
1968 911T
2002 996 4s
1988 944
 
  
View user's profile Send private message
   
alex yates
Brands Hatch
Brands Hatch


Joined: 06 Mar 2014
Posts: 14463
Location: The Ribble Valley, Lancashire

2000 Porsche 996 Carrera 4

PostPosted: Wed Nov 14, 2018 11:32 pm    Post subject: Reply with quote

Mine have sounded dog rough recently so after a good snoop round I noticed me clamps/sleeves between cat and back boxes where weeping slightly. Noticed it when cold under inspection as the condensation was blowing bubbles round the joints, but when hot, it's not as easy to see but sounded worse.
_________________
2000 Manual 996 C4 Arctic Silver Convertible


 
  
View user's profile Send private message
   
toohey
Monza


Joined: 22 Jan 2009
Posts: 181
Location: Naarfolk


PostPosted: Thu Nov 15, 2018 12:03 pm    Post subject: Reply with quote

Which silencer option did you go for? - only reason i ask is if its the switchable option and one side is switched the wrong way would make the exhausts have very different flow characteristics? There is a very noticeable difference in the switchable system on mine......
 
  
View user's profile Send private message
   
Marky911
Kyalami


Joined: 04 Jun 2009
Posts: 1915



PostPosted: Thu Nov 15, 2018 4:52 pm    Post subject: Reply with quote

My exhaust sleeves have dropped water on every set of sleeves and exhausts I've had, including on my GT3. Even when using brand new genuine sleeves.

I've always wanted to gun gum them up but Craig is adamant they're a clean fitting. I'm going to add some paste over winter though out of interest.

As Alex says if condensation can get out then obviously air can.

Good point about checking the valves but if TG fitted them I'd expect them to be fine. Thumb
 
  
View user's profile Send private message
   
Stoo.c
Monza


Joined: 07 Apr 2014
Posts: 191
Location: Hertfordshire


PostPosted: Fri Nov 16, 2018 11:25 am    Post subject: Reply with quote

Exactly what I did - put some assembly paste in some new sleeves and then it was finally sorted. Took me ages to actually work it out as it was intermittent depending on temperature etc. It sounded so bad that I thought I'd dropped a coil.
_________________
02 996 C4S
93 Skyline R33 GTS-t
91 CRX vtec turbo
01 986 Boxster S
 
  
View user's profile Send private message
   
Display posts from previous:   
Post new topic   Reply to topic   All times are GMT - 12 Hours
Goto page 1, 2  Next
Page 1 of 2

 
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum
You cannot post calendar events in this forum