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What 44 owners told NHTSA about the 2018 Mercedes-benz CLA

These are the actual owner complaints behind this car’s reliability verdict, filed with the federal government, unedited. They’re unverified reports, not confirmed defects: read them as leads for your pre-purchase inspection, not a diagnosis.

All (44)Crash / fire / injury (2)Electrical system (12)Engine (9)Airbags (7)Body & structure (6)Transmission & drivetrain (4)Fuel system (3)Communication (2)Seats (2)Steering (2)Electronic Stability Control (esc) (1)

9 of 44 complaints match · Engine · clear filters

Mar 8, 2026Engine

Corrosion of the fuel system (on a Flex Fuel rated vehicle that had used E85 blend regularly) causing sudden loss of power, misfires, lack of acceleration The vehicle experience sudden loss of power, multiple misfires, and potential damage to the engine. Had the vehicle been on the highway or attempting to merge with traffic this could have resulted in an accident See attached dealer diagnosis and replacement of multiple fuel injectors, fuel pump, and fuel rail. The dealer service manager stated (but did not document) that this was probably caused by using E85, despite the fact that the vehicle is rated for E85/flex fuel There were no warnings or indications prior to the incident

NHTSA ODI 11722825

Aug 20, 2025Engine

P052E Check Engine light on. Same part is defective on other models that use the same parts. My car is not included in the recall.

NHTSA ODI 11681776

Nov 19, 2024Engine

Check engine code PO52E - Positive Crankcase Ventilation regulator valve performance. Needs to be recalled

NHTSA ODI 11626114

Oct 28, 2024Engine

I am driving around 55K miles in this car, and my check engine light comes up. I head to a local place to get a code check. The guy looks it up and tells me this is pretty much with EVERY Mercedes CLA around that mile point.. So, I look up on reddit and other forums, and it's exactly what he said. Pretty much the PCV valve is faulty and costs around $1800-2500 to fix after 50-60K miles which causes emission problems and other safety concerns if not taken care of. It makes no sense how this is not a recall. Of what I read, Mercedes knows all about this and has done nothing, just leaving the drivers to take care of a problem that they did nothing to cause. I am not sure if this is for the NHTSA or what, but it is kind of unacceptable.

NHTSA ODI 11622361

Jul 10, 2023Engine & coolingFuel systemEngine

The contact owns a 2018 Mercedes-Benz CLA250. The contact stated that coolant was leaking from the engine with the check engine warning light illuminated. The vehicle was taken to an independent mechanic where the mechanic replaced the coolant reservoir cap. Several months later, the warning light re-appeared, and the contact topped off the coolant level and the warning light disappeared. Recently, the check engine warning light illuminated and took the vehicle back to the independent mechanic. The vehicle was diagnosed with a defective fuel injector and the contact was referred to the manufacturer for assistance. The contact was informed that the vehicle was not under recall and was referred to the NHTSA Hotline for assistance. The vehicle was not repaired. The failure mileage was approximately 118,000.

NHTSA ODI 11531259

Oct 12, 2021Transmission & drivetrainElectrical systemEngine

Regarding 2018 CLA 45 AMG: On 9-21-21, while I was driving approximately 45 MPH on a 4 lane road, suddenly the car completely shut down. A message simultaneously popped up that the car was disabled and instructed me to look up in manual. Immediately I turned right into the first driveway where the car came to a stop. I was able to restart car and drive home. At that point, the car's total mileage was 17,189. 10-7-21: Deeming the car unsafe to drive, I had the car towed to Mercedes-Benz of Raleigh for a pre-arranged appointment on 10-8-21with service advisor Christopher Moore. After the tech ran numerous tests, he found the ME control unit was faulty and replaced it at no charge. Since I drove it back home, I haven't driven it since.

NHTSA ODI 11436430

Nov 5, 2018Transmission & drivetrainElectronic Stability Control (esc)Engine

ACCELERATING OUT OF A LEFT TURN, THE CAR HESITATED MOMENTARILY THEN THE ENGINE COMPLETELY SHUT DOWN IN TRAFFIC. THE DASH INDICATED THAT THE CAR HAD BECOME INOPERATIVE, POSSIBLY DUE TO THE ELECTRONIC STABILITY PROGRAM (ESP) ISSUE.

NHTSA ODI 11149454

Jun 1, 2018Electrical systemEngine

2018 MERCEDES BENZ CLA 250. CONSUMER WRITES IN REGARDS TO ISSUES WITH VEHICLE STARTING AND SHUTTING DOWN WHILE DRIVING. *LD *JS

NHTSA ODI 11099669

Sep 26, 2017Engine

AS I ACCELERATED OUT OF A LEFT TURN, THE ENGINE SUDDENLY SHUT OFF, THE TRANSMISSION SHIFTED INTO NEUTRAL, AND THE DASH INDICATED THAT THE VEHICLE WAS 'INOPERABLE'. I PULLED OVER AND TURNED OFF THE IGNITION. WHEN I ATTEMPTED TO RESTART, THE VEHICLE STARTED WITH NO ISSUES.

NHTSA ODI 11029885

Working with the data? Download all 44 complaints as CSV · fetched from NHTSA July 19, 2026

How to use these: a complaint is one owner’s report, filed voluntarily and published unverified. Patterns matter more than any single story. If several owners describe the same failure at similar mileage, put that system at the top of your pre-purchase inspection list. Back to the full 2018 Mercedes-benz CLA verdict →