a buddy of mine just bought a 99 2.8 a6 quattro. he got it for cheap from an auto auction so theres a couple problems with it. one problem is that when the car is fisrt started up there a grinding sort of noise coming fromn the engine compartment. it only does it for about 5 seconds and goes away. it also makes an odd noise when the vehicle after the vehicle is shut off. im guessing that the two noises are related. the second problem is that the abs light is one and the brake light flashes on the dash. anyone know of any common problems that would cause these symptoms?

 

Its hard to say exactly what any of it can be, first run the fault codes. Autozone will run the engine related codes for free, or you can buy a VAG COM cable and diagnose it with your lap top, www.ross-tech.com Post the fault codes here when you get them.

 

Do you only hear the noise when the car is started 1st thing in the morning? Or is it constant whether the motor is warmedup or not? Anyways,I would firstcheck the oil level. It could be that you have low oil level and oil is having hard time getting up to the lifters in the morning, when the motor is cold.

And for the noise during the shut off, does it sound the same as the startup noise? If they are the same, than the start up noise isn't the lifters. You shouldn't hear the lifter noises during the shut down.

As for the ABS light and the brake lights, check codes as Auditech79 says.

 

The noise is the secondary air pump,probably going bad.

 

both noises sound similar. oil level is fine. and it seems to do it most of the time when u start it up. and then makes some sort of noise after you shut the car off for like 4-5 seconds. its odd. i dont get any CEL.
how can i check to see if the air pump is going bad?

 

the ABS/brake light combo is the ABS pump is bad. You can send it off to be rebuilt for about $200 and that should solve that. As for the other noise, symptoms would point me to the secondary air pump, its mounted on the passenger side under the front bumper cover. Try and have someone start the car and another person try and get close to the pump to determine if it is in fact the pump making the nosie