Misfires on all cylinders

Attached below is the torque spec of spark plugs. Thanks

My apologies. You noted that this was a CL and not a CLS but I looked in the heading for the vehicle when pulling that info.

Below is the info for the CL.

Unfortunately we are limited to what the manual says and this is where it shows this for a 2008 CL63 as you can see in the header of the picture.

Is this vehicle in the USA? If not, then that may be the issue. They more then likely put this in a different location for international vehicles and we only have USA manuals.

I looked through the post and did not see the knock sensor code. So if you have had that the entire time, what is the actual code?

More than likely that is a result of the serious knock that you have but if the sensor is faulty then it is not going to sense the knock and try to adjust for it. However, knock sensors are meant for detonation and not engine knocks like this so even if the sensor is an issue, I doubt that is going to go away.

I suspect that is a spun bearing and if you are feeling heat on the intake then I suspect there is either metal to metal causing heat or valves allowing combustion back into the intake due to them not sealing.

Okay. That code is stored while the others are all current/active. So that means it may have seen an issue but that is not causing this issue.

Just circling back on the compression check, did you ever check compression, at least on the cylinders that are misfiring? Have you drained the oil and checked for metal? Also, have you checked it again since it has been running for coolant again? I know you said it had coolant in the oil when you bought it.

I know we had an issue with the relay but you should be able to do what is called a clear flood and crank the engine and it not start for when you check the compression. This is where you hold the accelerator wide open while you are cranking the engine.

This will cut the injector pulse so that the engine doesn't start. Basically you are telling the PCM that the engine is flooded and you don't want any more fuel so that it doesn't hydrolock.

Clearly try this first just to be sure it works because while I show this in the manual, we have had enough issues with this that I wouldn't want have this be incorrect as well.

Thanks

Okay. Here is the process from the manual. It just tells you to remove all the coils and plugs which will clearly prevent the start and vent the cylinders so any fuel will evaporate quickly.