Hi everyone, I’m looking for some advice on a no-start issue with my 2018 Mercedes GLS450.

The car has around 50,000 miles and has been very well maintained. It was running perfectly fine with no warning signs, and I had the oil changed about 500 miles ago.

During driving and previous starts, there were never any unusual noises at all. However, after parking, the car suddenly would not start again. The dashboard lights come on normally, and when I press the start button, I hear a single “click,” but the engine does not crank at all.

This issue has actually happened before — in those cases, after waiting for a while, the car would start normally again. But this time, it will not start at all.

There are no fault codes stored. The battery has been replaced recently, and all interior electronics appear to function normally.

A local shop suggested it might be a timing chain issue and recommended engine replacement. However, based on my understanding, even with a timing issue, the engine should still crank.

Has anyone experienced a similar “click but no crank” issue on the GLS450 (M276 engine)? Could this more likely be related to the starter motor, solenoid, or wiring?

Any insights or suggestions would be greatly appreciated. Thanks in advance!

 

If you're sure the battery is OK, the next item to check is the starter and associated wiring. Do you have auto start/stop and is it used frequently?

 

The battery was replaced three months ago, and they fully charged and tested it. Initially, they said there was an issue with the wiring connected to the starter, and they replaced it, but it still didn’t solve the problem. The car does have an auto start function, but I have turned it off.

 

The shop should be able to tell if the starter is good or bad. Start there. I replaced the starter at 100k, a year later it failed again. So then I went with a Bosch rather than MB and no problems.

 

I agree -- if you've already had a shop do work on it, give them another shot at fixing it. If they can't figure it out find another shop with MB expertise.

 

Have the brake switch checked.
If bad will not let the car start.
Also try putting the car in neutral and try starting.

 

If you're going to deal with the same shop, the first thing I would ask them is what is it about the engine that requires replacement?

 

thanks a lot! I think they can not do it. I have change to another store

 

I had the car towed to another repair shop, and they fixed it quickly. The vehicle had been sitting at the first shop for nearly a month, so I’m not sure if the battery has gone bad due to sitting too long. Replacing the battery should resolve the issue. Thank you all!




Note/Recommendation: Warning Lights: -Found vehicle would not start on its own but would intermittently start with a jump pack. Tested and found battery very discharged. Noted multiple components previously taken apart including exhaust, air intake boxes, and transmission mount brackets, with missing hardware present. Also found engine drive belt cut. Raised vehicle and inspected starter; found aftermarket starter installed that appears new. Applied direct power to starter and engine started consistently, ruling out engine concern. At this time, no-start condition appears related to dead battery, with possible intermittent charging issue. Inspected alternator and wiring and found alternator charge cable not fully tightened at pre-fuse box, which would cause improper charging voltage to battery. Installed new engine drive belt, secured alternator cable, and reassembled all known loose components.

Jump-started vehicle and verified starter now operates consistently and alternator is charging properly after running vehicle for an extended period. Due to prolonged poor charging, battery appears weakened and not holding a proper charge; recommend attempting to drive vehicle to recover battery, but replacement may be required if condition persists.