Copart guy

Hi guys. A few months ago I bought a 2016 w205 C63s with 30k miles. Primary damage appeared to be vandalism, secondary was a mechanical. Estimated repair cost by the insurance company is 2700 dol.

Got the car delivered a week earlier. No visible vandalism on the exterior aswell as the interior. Car cranks but wont start. First thing I do is I plug the computer and check for codes. Appears to be the pump inside the tank is faulty. I check the fuel filler hose for sugar - no signs. Then I got the idea to listen if the fuel pump in the tank works. As I turn the key to position 2 there is no sign of life, as I crank the engine the pump doesnt sound like it should. I open up the lid under the back seat, get into the tank and take out the pump as I see it is absolutely oxidised and the tank is full of gunk because of the pump. Try to crank the engine again with the lid open to hear the pump - it's dead, no noise.

Get myself a used pump from the same model/low mileage c63. I clean the tank, install the pump, pour new gasoline in. Crank the engine - wont start, pump works as I crank the engine, doesnt work on position 2. Fault codes are gone, now the ecu doesnt show any faults.

Then my mechanic buddy appears and he tells me the engine sounds like its low on compression. I take out the ignition coils, take out the spark plugs - they appear to be in ok shape. The sound of the cranking engine is the same without spark plugs. My mechanic buddy checked and told me that there is fuel spraying out of all the cylinders.

I check the compression of the cylinders. Two cylinders have low compression of 4bar and 6bar. Others have 8bar to 10bar compression.
ignition coils fire up all spark plugs, they are working. Engine has fuel, spark and the air intakes arent blocked. I drained out to check the engine oil, it seems to be dark in colour but there's 9 litres of it.

I need your suggestions on what should I do next to find the solution. We were thinking maybe the timing chain has jumped and the timing now isnt correct, maybe you guys know if it's a common problem the w205 amgs have?

chassis

Which two cylinders have low compression?

Copart guy

Cylinder 5 and 6. Left side of the motor.

skratch77

Immobilizer might be triggered if car was in accident and rebuilt. God knows what the car was like before it went on copart.

There are some handheld obd scanners that can get it back to running if it's been de mobilized from an accident.

See here in this video how car needs to be reset to start.
https://youtu.be/-1Kk_4FZVbg

PTG

it wouldn’t even crank typically with an immo issue. Is the fuel pump activated? This is a common step in the process with later model MB’s. Injector coding and fuel pump authorization.

The low compression issue however is a bigger concern. If you need help let us know.