Inspect cylinders using a light probe - AR01.00-P-0200GZA (ML350, ML550, GL450, GL550)

WARNING: This page does not describe the selected car, but rather 28 other vehicles, including the 2012 Mercedes-Benz GL550, 2012 Mercedes-Benz GL450, 2011 Mercedes-Benz ML63, 2011 Mercedes-Benz ML550, and 2011 Mercedes-Benz ML350. However, it is still accessible from the selected car via links, so may be relevant.

ENGINE 272, 273 in MODEL 164, 251

Fig 1: Inspecting Cylinders Using Light Probe (Engine 272, 273)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.

	Remove/install
	Risk of death caused by contact with parts conducting high voltages.	Do not touch parts which conduct high voltages. Persons who wear electronic implants (e.g. heart pacemakers) should never perform any work on the ignition system	AS15.10-Z-0001-01A
	Risk of injury to skin and eyes caused by handling hot or glowing objects.	Wear safety gloves, protective clothing and safety glasses, if necessary.	AS00.00-Z-0002-01A
	Risk of death caused by vehicle slipping or toppling off the lifting platform.	Align vehicle between columns of vehicle lift and position four support plates at vehicle lift support points specified by vehicle manufacturer.	AS00.00-Z-0010-01A
1	Turn key in ignition lock to position "0"	Vehicles with Keyless Go, code 889: Press Keyless Go start/stop button repeatedly until ignition is switched off. Remove the Keyless Go transmitter card or transmitter key from vehicle and store beyond reach of the transmitter (at least 2 m).
2	Remove air filter housing		AR09.10-P-1150GZA
3	Remove ignition coils		AR15.12-P-2003GZA
4	Remove spark plugs		*BA15.10-P-1001-01C
5	Rotate engine at crankshaft center bolt in the engine's direction of rotation until piston of cylinder to be inspected is at bottom dead center		Fig 2
6	Connect cylinder inspection lamp (1) and insert flexible endoscope (test probe) (2) of cylinder inspection lamp into cylinder to be inspected through tapped bore of the spark plug
	Checking
7	Check cylinder wall, piston crown and valves	If there is "scoring" (wear to the cylinder), the cylinder wall has become rough and the honing marks are no longer visible. In case of doubt, remove cylinder head:↓
		Remove right cylinder head	AR01.30-P-5780GZA
		Remove left cylinder head	AR01.30-P-5770GZA
	General information on inspecting cylinder walls		AH01.00-P-0300-01VA
8	Inspect other cylinders in the same way
9	Install in the reverse order

SPARK PLUGS

Number	Designation		Engine 272	Engine 273
BA15.10-P-1001-01C	Spark plug on cylinder head	Nm	23	23

Fig 2: Identifying Wrench Socket (001 589 65 09 00)

Courtesy of MERCEDES-BENZ OF NORTH AMERICA.