Power Assist Brake Problems of Audi A4

This is the second time this has happened in similar circumstances in the last two years to my wife. The temperature was under 4 degrees and extremely windy and snowing. She warmed the car up for 15 minutes before driving it. The engine temperature gauge was a little bit off cold. The heat was on and working fine. The car did not want to go, and hesitated during acceleration. She drove a mile to the interstate with no issues and the car warmed up. Once on the interstate, she drove about a half mile accelerating to about 65. When she tried to pass, and began accelerating the throttle froze. The rpms increased quickly and significantly. She tried to brake, but the brake pedal was not effective. She downshifted using the tiptronic, the car went faster. She put it into neutral and the rpms revved out. The car approximately was going 90 miles an hour or greater at the apex of my speed. She got off the interstate by using my e-brake, and turned the car off at the stop light because she feared it would not stay stopped. She drove about a half mile to work using the e-brake and brake to slow down, and nearly hit a tree trying to stop. She turned the car on again after she parked to see if the throttle was still stuck, it was. Three hours later I arrived, started the car, and the throttle was no longer stuck. I called the dealer that day, explained the issue, and they wouldn't take the car until 6 days later. They told us that it was the car mat stuck under the pedals, and it was necessary to keep the appointment. I took the car to get looked at anyway, they inspected to find egr valve clogged causing moisture buildup and throttle to ice over. They replaced the egr valve, air pump and vacuum hose and cleaned the throttle body. This totaled $546. 30. There is a recall on the a6 throttle body for the same year, engine, transmission and the exact same part number! but Audi corporate told us it did not apply because we have the A4 not the a6 and was not concerned or willing to help.

See all problems of the 1999 Audi A4 🔎.

Brakes power assist fail at / just after startup when selecting reverse or drive while the air conditioning is on. I reported the problem to the Audi exchange in highland park, IL last year. They were unable to reproduce the problem, at the time as I was unaware that it only occurred when the a/c was on and at low speed after initial start up. This occurred again this summer when I was trying to move out of a parking spot and was unable to stop. The result was that I hit another car at low speed causing no damage to either.

See all problems of the 2000 Audi A4 🔎.

12/2004, purchased certified 2001 Audi A4 from beechmont Audi in cincinnati, ohio. Car had a comprehensive 300+ point inspection performed by Audi as per paperwork. 5/20/2001, vehicle taken to bluegrass Audi in louisville, kentucky for a brake assist problem. Several days prior to brining the vehicle in, I was in reverse leaving my garage when I found that I needed to push the brake pedal to the floor to slow and stop the vehicle. I noticed when I drove forward the problem went away. I tried backing up again and found the braking to be normal. Later that afternoon I was going to lunch and when I backed up the vehicle didn't have any brake assist again and I had to push on the brake pedal with maximum force. Took the vehicle to my local Audi dealership and was told by the service manager that the car needed a brake flush. They performed the brake flush, but that didn't fix the problem. I returned the vehicle back to Audi several days later and was informed that they found the problem with a grommet that connects two vacuum hoses at the bulkhead. They added a clamp to stop the air from escaping the system, but the next day it proved not to work. They also informed me that the brake pads and rotors were within Audi limits. Took the vehicle back and was informed that they needed to replace the grommet. After the item was replaced, it still has the same problem as of 7/4/2005. In summary, the vehicle has a brake assist problem in reverse after the vehicle has been sitting for a short period of time. In my un-scientific research, the brake assist fails if the vehicle has been sitting and not running for less than 2-3 hours. When this occurs, the brakes operate, but maximum brake pressure is required to stop the vehicle until the pressure builds up. This could be an isolated incident, but I thought I would pass this information along just in case there are others with the same problem.

See all problems of the 2001 Audi A4 🔎.

My 1997 Audi A4 has experienced almost non braking in cold/wet conditions. When brakes are initially applied during these conditions there is almost zero braking for 50 feet at 35 mph or less. I have come very close to rear ending a few cars that cut in front of you. I have contacted Audi of America and there response was that no known poor braking condition exists when brakes are cold/wet. Yet there is a news bulletin on Audi's own european web site indicating that there is a problem with brakes when wet. . Read more...

See all problems of the 1997 Audi A4 🔎.

Vechicle has a severe decrease in breaking power in wet conditions, especially in colder weather. It takes up to 5 seconds for the vechicle to start to slow down in these conditions.

See all problems of the 1998 Audi A4 🔎.