Huge win for car owners! All TSBs to be made public. The Center for Auto Safety just made the NHTSA (US Government) make public the full text of all TSBs from now on. They are the same organization that has petitioned the NHTSA & filed lawsuits to protect car owners over exploding gas tanks & other major safety issues. Whenever you drive in your car, you are safer thanks in part to a lot of work over the years by this small but very effective consumer advocacy group.

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8.3

pretty bad
Crashes / Fires:
0 / 0
Injuries / Deaths:
0 / 0
Average Mileage:
4,098 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2015 Mercedes-Benz C300 engine problems

engine problem

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2015 Mercedes-Benz C300 Owner Comments

problem #6

Sep 142015

C300

  • 400 miles

A D V E R T I S E M E N T S

New vehicle purchase 07/11/15, has been in/out Mercedes shop since the date of purchase due to electrical problems where car was flooded by rain when purchased due to a plug was not placed in the car by the manufacturer. Requesting a replacement due to electrical problems multiple times with being stranded. Vehicle would die and not crank with having to pull over to the side of the road multiple times due to vehicle malfunctioning. Vehicle was recently towed due to entire system went out and was stranded with vehicle not cranking when parked and died completely. Vehicle electrical system was recently found to be corroded and was changed out multiple times. Vehicle is currently running like a truck since this last repair. This vehicle is a lemon and should be replaced due to the lemon law and the vehicle was flooded by rain due to missing plug from manufacturer day one of purchase. Just received the car back 10/26/16 after two weeks, with the vehicle being in for dying and malfunction due to electrical problems. I'm afraid to drive this vehicle for a distance due to the electrical problems and in fear of being stranded again, with Mercedes having no guarantee for my safety. Vehicle VIN# at Mercedes shows all the problems with this vehicle being in/out of the shop for electrical problems and malfunction as well as changed out electrical system twice. Vehicle problems started September 2015. This vehicle is considered a lemon and I should be given a replacement due to this vehicle being flooded from the rain and having ongoing electrical problems. This vehicle has hindered me from traveling and has caused me frustration due to all the problems. This vehicle should never be allowed on the road again due to flooding and electrical problems and can cause a death. Mercedes is being negligent, with trying to repair and not salvaging as the lemon law requires.

- Ponte Vedra Beach, FL, USA

problem #5

Apr 072016

C300

  • 10,500 miles
While driving "collision prevention assist plus inoperative" message appears on dashboard. Car loses its ability to accelerate. Occurred twice (January 2015) on city streets forcing me to pull over to the side of the road and restart my car, the error disappears and I am able to drive normally. 4/7/16 occurred while traveling 65mph on an interstate. I lost ability to accelerate and was almost rear-ended by a semi-truck. The vehicle was serviced at a Mercedes dealership on 1/11/16 the highway incident occurred after the "fix". it is currently back at the dealership being tested by the service department. I am told the current fix is to replace all the senors. I have opened a case with mbusa to repurchase the vehicle given the initial repair did not work and put me in perilous highway situation. I purchased the vehicle in October of 2015.

- Canonsburg, PA, USA

problem #4

Aug 282015

C300

  • 1,000 miles
The contact owns a 2015 Mercedes-Benz C300. While driving at various speeds, the vehicle would independently decelerate with the RPM gauge reading between 4,000-5,000. The failure occurred intermittently. When the vehicle was shut off and restarted, the vehicle returned to normal. The vehicle was taken to the dealer for diagnostic testing; however, the failure could not be duplicated. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was 1,000.

- North Branford, CT, USA

problem #3

Jan 202016

C300

  • 8,500 miles

A D V E R T I S E M E N T S

Two issues, purchased a certified pre owned vehicle. At 8900 miles, we noticed the car was idling very rough on a cold start, almost the sound of a diesel. The sound would resolve after 10 minutes of driving. Service informed us that there was a recall on the rods and pistons. We had the engine rebuilt, and the noise is the same, if not worse. The car sounds nothing like laterbuild '15 models or '16 models, nor does it run as smoothly. Secondly, 5 occurrences involved inoperative collision prevention assist warnings and inoperative anti-skid warnings appearing on the dash causing the car to reduce operating speed to 20mph max. Car needed to be shut off and restarted after a 5 minute period each time these warnings appeared, in order to drive over 20mph. The vehicle was serviced for these warnings twice. The first service diagnosed the car with a coding issue. The second, involved replacing modules. This all occurred during the two months of owning the car. We notices several similar complaints regarding the early build 2015 C300S, and decided to cut our losses and purchase another vehicle. We did not feel safe in that car.

- Watertown, CT, USA

problem #2

Dec 222015

C300

  • 2,438 miles
Loud engine knocking when engine is cold. Diagnosed as incorrect/unfavorable tolerances of piston wrist pins that will ultimately lead to engine failure. Diagnosis happened with odometer at 2,438 miles.

- Riverside, CA, USA

problem #1

Apr 012015

C300 4-cyl

  • 1,750 miles
1. warning light "inoperative collision prevention assist plus" comes up on the display on & off when driving. Car was sent to service on 4/22 but didn't duplicate the issue. Car was returned to me on 4/23. 2. on 4/24, warning light "inoperative collision prevention assist plus" comes up again plus the yellow "engine light".

- Milpitas, CA, USA

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