I am having some weird pop/pulsing sensastion happening with my car. ITs a 95z28 A4. For the past week or so when i start the car and its still pretty cool but while i am sitting at a light i notice a popping sensation in the brake pedal. It feels like the moment your foot is slightly off the brake its creaking forward but I know that is not whats happening. Any thoughts on this? I have noticed that when the car sits for a while its a pain to start too, i plan on getting a fuel pressure checker since i just redid the fuel system about a year ago. I changed the plugs this weekend but i noticed the pop is still there.


Thanks

 

sounds more like a abs problem. have you had it scanned for trouble codes?

 

not yet. ill take my laptop with me and run a scan tomorrow. i was also wondering if it could be a knock sensor? i only feel thru the pedal

 

ran a scanner and no codes are popping up.... :/

 

double check and make sure plug wires got put back on in the right place. i do one plug at a time after getting a couple crossed. how did fuel pressure look?

 

I do the same thing when changing plugs as well, but this was going on slightly before the plug changing. It just has gotten a bit more noticeable over the past few days. The popping is inconsistent, it doesn't seem to be a spark issue/fuel or detonation feeling I don't think. I am curious about the ABS, the inop light has been on for over a year when I changed the posi I put on in for a 98 and the speed sensor didn't link up blah blah. The fuel isn't an issue like I thought either. Im wondering if something is wrong with the brake pedal itself? I only feel it in the brake pedal, while im sitting at a complete stop, it doesn't do it while I am decelerating.

 

the abs was my first reaction to reading op. if the abs unit is getting bad info it will mess with brakes and could pulse the pressure thinking its in a skid situation.

 

My guess is you checked for engine codes. If you have the ABS light on then you have a ABS code. You may now have ABS code(s). You would expect to see no reference signal to ABS rear code. Maybe Gary will chime in but I would think once ABS system saw a problem that large it would just not do anything making unlikely it was a ABS issue.

Is it possible we are talking about a brake sticking a little?

 

I really dont know. Its pretty frustrating. Its kind of difficult to describe over a computer. The issues is at random but i do notice it in the morning for sure after the car is warmed up a bit and i make it to the red light about a quarter mile up the street. I push hard on the brake to make sure im sitting still but it does give off that feeling in the pedal like the car is creaking forward like an intermittent popping. Rack and pinion really wouldnt give off anything weird like that? IM at a loss for words right now lol i just dont want it to be anything serious and im overlooking it

 

Maybe you could find a trusted mechanic? I have had customers try to explain things on the phone for 15 minutes and we got nowhere. 30 seconds into the test drive I knew what it was.