iamraymond

Hi All,

A coworker of mine owns a B5 S4. He has been having problems recently with the car not starting on random occassions. The battery was recently replaced in hopes of solving the issue, but the problems still occur.

When you try to start the car, I cannot hear the fuel pump running and the starter does not crank. All the eletronics work fine (clock, radio, headlights) and the needle of the battery gauge is in the center, but the car just doesn't start. The clutch is being depressed all the way down.

The strangest thing is that even with the new battery, if we boost the car with another car, then it will start absolutely fine. There is no hesitation with the starter and the car just comes to life as normal.

Do you guys have any suggestions as to what might cause the issue? I don't think its the starter, because it starts fine when boosted and it does not happen all the time. I think it must be something electrical. I'm not too familiar with these cars so your help is much appreciated (and needed!).

Also, he mentioned that the EPC light on the cluster was on - is this normal?

Happy New Year and TIA!

pber13

have you tried testing the alternator? also maybe try cleaning the battery terminals to see if they're corroded...other than than I can't think of anything else off the top of my head. I'll ask my teacher tomorrow and see what he thinks

iamraymond

Any other ideas?

S4andTLS

I'd say it's your starter solenoid which acts up because it's getting worn and with extra juice it can start. So you need a new starter, I got mine at advanced auto I believe-stock rebuild.http://www.2carpros.com/how_does_it_...enoid_work.htm

nobodeuno

I had something similar with my car. It started out being infrequent failing to start, I figured I dropped a cell in my battery because when I would get it jumped off it would start up. I replaced the battery and it seemed fine for a while...then it really quit starting and no matter what I did it would not start. I was convinced it was the fuel pump because like you I couldn't hear the pump start up.

I finally pulled codes on the car and I had a code for crank position sensor. Replaced that and it started right up! Now I'm not saying that yours is the exactly the same thing but for whatever reason the crank position sensor (and probably many sensors) prevent the fuel pump from getting any voltage (probably a fail safe) and thus it won't turn on. I should have pulled codes right when it started happening so I can't say for sure I didn't have two issues but I suspect that I didn't need a new battery and that the problem was a flakey sensor. Lesson learned pull VAG codes before troubleshooting further....would have saved me a lot of time.

Hope this helps!