Mercedes 2018 GLC 300 - Check Engine Light

2robertc
Tue, 22 Apr 2025 13:53:27 +0000
Maintenance/Repairs

Hi - So my check engine light has been going on and off for at least the last year or two. It’s been to the dealer a couple of times and they have not been able to diagnosis the problem until recently when on 4/8 they told me they found 2 problems.
(1) the “valve for crankcase ventilation has a malfunction. The actuator is blocked”. They apparently fixed this under the extended warranty for the vent value - they installed a plug and performed a software update - NO CHARGE. I picked up the car. The light was off. A few days later the “Check Engine” light came back on. I brought the car back to the dealer yesterday (4/21). The second problem (which he noted on 4/8 and he was able to confirm) was a “sensor that is part of the gas tank”. This repair will cost $4,372. The service advisor I spoke to was not able to tell me what would happen if I didn’t do the repair. When pushed he said, the first thing that would “probably” happen would be the fuel gauge would not register but that the car could also have problems starting. Apparently, this error is all tied into the electronics.

I guess I’m just looking for validation before I replace the gas tank.

I appreciate the advice.

8 posts - 4 participants