Safety regulators are investigating braking problems in BMW 328i cars from model year 2013 after receiving four consumer complaints.
The preliminary evaluation was opened after the complaints alleged difficulty in braking the car and increased stopping distance, according to documents filed with the National Highway Traffic Safety Administration. It estimated the number of BMW cars in the probe at 90,000.
BMW officials could not immediately be reached to comment, but according to NHTSA documents, there were no reports of accidents or injuries.
Three of the complaints indicate that the dealer in each case diagnosed the problem with the vacuum pump, according to the NHTSA.