w210 diesel detonation
 

I found something that I never heard before on a diesel.After you shut the engine off(606 diesel,W210),after one-two seconds will have a slight detonation,sounds like my old 1975 pickup truck that took 3 minutes to stop...not that bad,only one detonation,there is allways that engine noise after has been shut off,every time,no exception.

I'm not sure what's making the noise (Gilly? MB Doc?), but it's not the engine. I believe it's some of the computer-controlled parts on the engine being activated for whatever reason. Shut off the engine with the hood open, and you'll see that the noises persist while the engine is not turning.

Its the engine,will turn one more time,partially,after coming to a complete stop 1-2 seconds before,I checked that using another person to shut the car off.

Now that's just odd. I have absolutely no idea what could cause this sort of behavior.

Never heard of such a thing...the only thing that can cause a diesel to "run-on" is additional fuel being introduced or buring off. Maybe the fuel shutoff solenoid isn't closing all the way and a small amount of fuel is leaking into the IP, possibly through a leaky injector? This is certainly not typical or normal in any way... maybe it's kicking backwards after shutdown but it would be unlikely to do this every time and mine has certainly never exhibited this behavior...shut down is stopped, completely, every time on my 606.

Hmmmm.......
 

I belive you are hearing the IFI Electrohydraulic Shutoff Actuator in action.
Every time you shut the key off from Position 2, the shutoff valve closes.
The double knock is the internal Balls seating against their seats via spring tension. Kinda loud, isn't it?

DR.D

I've never heard mine click at shutdown and it also stops instantly when the key is turned off.

The only thing I hear after shutdown is some residual vacuum sounds.

I can hear a subtle click of the solenoid opening when the ing is turned on if the hood is up.

He's saying here the engine actually turns after shut-down...it's not a solenoid noise if he's observed the engine actually turning...that's why I said it sounded like maybe fuel was leaking in or the engine was somehow "kicking backwards" after shutting down...though mine has never done anything like it and I can't explain why his would.

Could it be he has a residual buildup of excess carbon in the cylinders that glows when running and ignites leftover vapor/fumes after shutdown acting as a glowplug? How many miles are on the engine on what kind of fuel?