[s-cars] Cold start issue, brake fade
munrof at sympatico.ca
Wed Oct 4 09:58:11 EDT 2006
Your bogging issue may be a bad oxygen sensor. I just had the same problem
on my S6. Replacing the sensor fixed it. The old sensor was actually loose
in the manifold, so it may have had a bad ground that prevented the sensor
heater from working properly, although the car did bog a bit after shifts
even when hot. I'm still sorting through issues on the new to me S6 and I
was glad to resolve that one so easily. Your issue may also be a faulty cold
start system. The temp sensor on the back of the head sometimes fails and
disables cold start.
Does your car have a belly pan? The NACA ducts in the bottom of the pan
direct air onto the front rotors to cool them. No pan = poor front brake
The "fade" issue may also be low boost pressure or a bad bomb. Did the brake
warning light come on? Is the low pressure sensor on the servo connected?
This can become mysteriously disconnected to "solve" warning light issues.
From: s-car-list-bounces at audifans.com
[mailto:s-car-list-bounces at audifans.com]On Behalf Of Mark Rivera
Sent: October 4, 2006 9:35 AM
Subject: [s-cars] Cold start issue, brake fade
First thing in the morning when I start my 93 S4, it wants to die.
Sometimes it does, sometimes it just stumbles badly until I blip the
throttle. After the revs get up to about 1500, it clears up. The only
other thing I notice when it's cold is a pretty deep bog between shifts just
after letting the clutch back in. This carries on for the first minute or
so. This happens when I go out for lunch as well, but the stalling only
happens when it's dead cold in the morning. Ideas??? FWIW, the car runs
very strong when it's warm.
I flushed and bled the brakes last night, and while it firmed up the pedal a
little, it's still softer than I'd like. I'll probably invest in some
braided lines soon. I took the car for a spin after I was done, and tried
some heavy braking from about 80-45mph. After about 3-4 applications like
that, the brakes were fading really bad. My foot was almost to the floor, I
was almost out of my seat standing on the pedal, and could not get the ABS
to activate. Matter of fact I've never had the ABS step in yet, and I
haven't locked a wheel yet either. I cruised for about 5 minutes to cool
things down, tried again, and most of the braking had returned. I know the
brakes are sorta weak on these cars, but I didn't know it could be this bad.
I don't wanna pony up for a caliper/rotor upgrade just yet, but would like
some pad suggestions to replace what I think are stock pads with wear
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