Down Pipe Rattle. - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


2000-2005 Discuss your 2000-2005 Bonneville SE, SLE, and SSEi Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Reply
 
 
 
Thread Tools Search this Thread
Old 07-31-2007, 10:18 PM   #1
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Apr 2007
Location: NEW YORK
Posts: 85
Thanks: 0
Thanked 0 Times in 0 Posts
RODBONNEVILLE is on a distinguished road
Default Down Pipe Rattle.

Hello all,
I had rattle under the car so I suspected it was the catalytic converter since I had the same problem on a 1992 Pontiac Bonneville ssei that I use to own. However, I changed the converter with a magnaflow on the 2000 Bonneville and still had the rattle..further inspection and found it to be the down pipe...Will the rattling down pipe cause any problems to the engine like poor mpg'*,engine back pressure,lost of horse power or even engine damage?
Thanks.
Rod.
RODBONNEVILLE is offline   Reply With Quote
Old 07-31-2007, 10:51 PM   #2
Junior Member
Posts like a Ricer Type-R
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

It could very well cause false KR, resulting in decreased performance and fuel mileage.
willwren is offline   Reply With Quote
Old 07-31-2007, 11:12 PM   #3
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Apr 2007
Location: NEW YORK
Posts: 85
Thanks: 0
Thanked 0 Times in 0 Posts
RODBONNEVILLE is on a distinguished road
Default

Quote:
Originally Posted by willwren
It could very well cause false KR, resulting in decreased performance and fuel mileage.
Thanks Willwren,
Sorry, I'm still fairly new to club..What is "KR"?
RODBONNEVILLE is offline   Reply With Quote
Old 08-01-2007, 12:49 AM   #4
Senior Member
Posts like a Turbo
 
Join Date: Feb 2003
Location: Northern Twin Cities
Posts: 268
Thanks: 0
Thanked 0 Times in 0 Posts
Freddi is on a distinguished road
Default

KR = Knock Retard

Definition: The engine management computer (PCM) checks for predetonation using a knock sensor. The knock sensor could pick this up (the downpipe rattling) as 'knock', and will retard timing to prevent engine damage. This in turn could reduce gas milage, power etc.

Make sense?
Freddi is offline   Reply With Quote
Old 08-01-2007, 06:50 AM   #5
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Apr 2007
Location: NEW YORK
Posts: 85
Thanks: 0
Thanked 0 Times in 0 Posts
RODBONNEVILLE is on a distinguished road
Default

Quote:
Originally Posted by Freddi
KR = Knock Retard

Definition: The engine management computer (PCM) checks for predetonation using a knock sensor. The knock sensor could pick this up (the downpipe rattling) as 'knock', and will retard timing to prevent engine damage. This in turn could reduce gas milage, power etc.

Make sense?
Yes it does make sense make sense, thanks...Now can this downpipe be welded or is that a bad idea?
Rod.
RODBONNEVILLE is offline   Reply With Quote
Old 08-01-2007, 08:51 AM   #6
DINOSAURUS BOOSTUS

Expert Gearhead
 
BillBoost37's Avatar
 
Join Date: Mar 2005
Location: Enfield, CT
Posts: 41,391
Thanks: 0
Thanked 0 Times in 0 Posts
BillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of light
Default

Have you been able to determine what is rattling on the downpipe?

Our downpipes are a two layer pipe with welded ends and flanges. Can't say that we've ever heard of one rattling before unless a bolt came loose.
BillBoost37 is offline   Reply With Quote
Old 08-01-2007, 06:10 PM   #7
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Apr 2007
Location: NEW YORK
Posts: 85
Thanks: 0
Thanked 0 Times in 0 Posts
RODBONNEVILLE is on a distinguished road
Default

Quote:
Originally Posted by BillBoost37
Have you been able to determine what is rattling on the downpipe?

Our downpipes are a two layer pipe with welded ends and flanges. Can't say that we've ever heard of one rattling before unless a bolt came loose.
When the cat was taken off I could see it was two layers but, I was not concerned with the down pipe thinking it was the cat rattling..As far as where the rattle is coming from not really sure..when put on the lift and banged on the down pipe can hear the noise was coming from there...I see there is a rigged round attachment on top connecting to the exhaust manifold..Is that part of the down pipe? or is it the flex flange? could that possibly make noise?
RODBONNEVILLE is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Cracked down pipe flex pipe. XEN 2000-2005 13 05-01-2009 10:01 PM
rattle buzz rattle smellbird General GM Chat 1 10-28-2007 11:54 PM
Catalytic rattle rattle rrounds 2000-2005 4 01-27-2007 01:57 AM
Rattle Rattle Trusty Bonneville 1992-1999 7 05-18-2004 01:55 PM
Rattle, Rattle, Thunder Clap - Boom Boom Boom ---HELP--- CorradoSLC 1992-1999 12 08-28-2003 01:16 AM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 04:36 AM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.