johnalexander

Hello MB World Community,

I'm reaching out for some advice concerning a starting issue with my 2020 GLC 300, which currently has 44,000 miles on it. Despite its low mileage, the car has been hesitant to start up for the past couple of months and occasionally takes 2-5 cranks before the engine successfully turns over. I daily drive the vehicle and the issue seems to be random whether it hesitates to start or instantly turns over.

The most troublesome incident occurred today after grocery shopping: the car failed to start after the first engine crank, taking three attempts before it finally turned over. Each of the first two attempts involved the engine cranking five times without starting.

To diagnose the problem, I've visited AutoZone on three different occasions to check the starter, alternator, and battery. All components passed their tests. Given that my battery was about 4 years old, I opted to replace it with a brand-new one from the dealership two weeks ago. Unfortunately, this didn't resolve the issue as the car continues to struggle with the same startup problem and seems to be getting more frequent.

This issue happens regardless of holding the engine start button or simply clicking it. The problem also occurred two times when the engine cut out at an intersection with the start/stop feature.

I've attached a video I recorded today right after the grocery store incident to demonstrate what I'm experiencing.

Has anyone else faced a similar challenge with their vehicle? Any advice or insights on what steps to take next would be greatly appreciated!

Thanks in advance for your help!

https://drive.google.com/file/d/1Jrb...ew?usp=sharing

DanD.

No reason to check alternator or battery, i would check spark plugs, fuel pump, injectors.
Especially when its happening.
If car hesitate to start for a few mins, pull the spark plugs see if they are wet they should.

TomasL

I would do a fault code readout. Even if you don't have any fault messages in the cluster there can be some interesting stuff there that leads you in the right direction.

jsdanish

Spark plugs are sequenced by direction, make sure they are indexed correctly

mikapen

Definitely.
I'd suspect a cam position sensor or something like that.
I don't think it's the "usual suspects" like plugs.

jsdanish

Cam sensor is a hard code, would have displayed, The plugs must have the electrodes facing the intake port- it starts with direct injection, also fuel pump pressure must be correct

mikapen

See my insertions.
Needs an in-person diagnostic, with equipment that Indy's won't have.
The engine is also designed to stop on a compression stroke, so first spark spins engine. Or used to.

Not all sensors remember faults, and it takes a well-trained tech to investigate.