i am only guessing
but displacement of the CYL should be the big diff not the location of the sensor.

it is on the drivers side of the engine. and i dont mean back. i mean right side if you are standing with your belt buckle on the radiator.

if i recall about 2/3rd of the way back of the engine..and 1/3 the way down - use a flashlight and look for some wires going to a clip on elect fitting -
take that off and you will see and inch or two black round sensor.

I may have even found it 1st timw by fondling around for it.

THis is on the ML320-I know nothing about the others.

__________________
Steve Danville
what i did myself.
CPS
rear shocks
MAS x 3.
SparkPlugs (twice)
Fuel pump & Filter
Window switch
replaced both failed horns with Honda horns.
Cleaned ERG Tube
Oil changes
Oil consumption Fix
Brake Pads
A/C Recharge
Anti-Freeze change X 2.
Front Shocks. Monroe. $90
Mercedes Warrenty Work:
Harmonic balancer,power steering clamp. Cat converters.Drive Shaft Bearing.s
Replaced Outer Lower Tie Rods and front lower ball joints at 156,000 miles