Popping Sound In My Exhaust

[David.Ullrich at ferguson.com]

It could also be due to a low backpressure exhaust system. When I went to an aftermarket 2.75" on my CGT I started getting throttle lift popping. It's pretty common on hopped up cars. My Impala SS with dual straight pipes (no mufflers) pops too. Could these be mini-backfires? I guess but both cars are tuned perfectly. Maybe the lower backpressure allows for easier backfiring?

Dave

1987.5 Audi Coupe GT "Special Build" 2.3 - Anthracite Black
1998 VW Passat GLS 1.8T - For Sale CHEAP


-----Original Message-----
From: Rave Racer [mailto:Ravewar at rogers.com]
Sent: Friday, May 03, 2002 8:40 AM
To: Iain Atkinson; quattro at audifans.com
Subject: Re: Popping Sound In My Exhaust



    Nah.  I like my popping sound, but I'm crazy.

       ... However, it is a backfire.  This is not entirely unusual in
itself, but if your exhaust is intact then you may decide to try to tune
this out.  It is basically extra fuel, that is unburned, firing sometime
after it has passed your exhaust valves.  This can cause problems down the
road clogging or just plain destroying your Cat and or leaving Carbon
deposits on your valves, headers and exhaust, not to mention the
environmental impacts.  If you need to pass an emissions test soon, I'd get
it looked at.  The back fire can be a problem caused by the fuel
distributor, low spark, to high exhaust flow, oxygen sensor, timing....
there are many reasons.  Under the right circumstances any car will back
fire.  Alot of people don't realize that their cars are backfiring because
their exhaust is quiet enough to keep it from being obvious.  In my case my
car sounds like "Vroooom POW, banga bang", but like I said, I'm crazy.  You
might want to get professional advice before doing any major work.  You may
only need an adjustment on your fuel distributor ($20 job at an experienced
Audi Mechanic).  I'd even suspect that a nice new set of good spark plugs
may do the trick.

       Rave Racer
'89 Jetta 1.8L 16V GTX
 http://www.vwot.org/members/Pete.html
'87 Audi 4000 Quattro Sedan
 http://www.audifans.com/registry/view.php?action=viewCar&carid=110
'72 Triumph GT6
 http://motorcities.com/contents/01I3H011116682.html
'83 Toyota Tercel (yoda)     Possible future Sandrail donor...  Maybe
----- Original Message -----
From: Iain Atkinson <iain.atkinson at tesco.net>
To: <quattro at audifans.com>
Sent: Friday, May 03, 2002 8:03 AM
Subject: Popping Sound In My Exhaust


> Hello All,
>
> my 87 Coupe Q (2.2 5 Cyl engine) makes a popping sound in the exhaust when
i
> lift off the throttle at anything above 2000 rpm. Any ideas what the cause
> might be and is it something i need to worry about????
>
>
> TIA
>
>
> Iain
>