How To Change Spark Plugs On 2004 Benz S500

Ignition System

Parts in EPC related to ignition system.

This page covers W220 petrol engines M112 (V6 engine used in S350) and M113 (V8 engine used in S430 and S500).

The W220 uses a twin-spark ignition arrangement for each cylinder and thus the V8 has eight ignition coils (or ignition plug packs). There is one coil pack per cylinder, which produces spark for two spark plugs per cylinder.

Misfiring oft occurs because of burnt ignition coils, faulty ignition cables and spark plugs. These elements have to be replaced regularly.

In case of failure, the following codes can be thrown:

P2050 Misfiring, Damages TWC (P0300) STORED
P2056 Misfiring of cylinder 4, damages TWC (P0304) STORED
P205B Misfiring of cylinder 8, damages TWC (P0308) STORED

Notes on avoiding damage to ignition arrangement

The principal points:

No tests such as holding an ignition HT Wire at a distance from ground and observing a spark must be performed.
Do not operate the ignition arrangement at starting speed unless all of the HT Wires are connected.
Before working at cranking speed e.g. to check pinch pressure level, switch off ignition and disconnect Ignition Command Unit from 12V.

Notes on avoiding damage to ignition arrangement:

To avert harm to control unit, only connect and disconnect the two connectors on control unit when ignition is switched off.
Terminal i of ignition coils must not exist short-circuited to GND, e.m. as antitheft protection.
But install original ignition arrangement components.
Do not operate ignition system at starting speed unless all of the ignition cables are continued.
No tests such as holding ignition cable four at a distance to GND, unplugging a spark plug connector or pulling cable 4 out of the ignition coils, may be performed at starting speed or when the engine is running.
Every loftier voltage circuit must be loaded with at least 2 kΩ (spark-plug connector).
If information technology is necessary to test the ignition spark when providing roadside help, this must just exist done with a spark plug at a cylinder ignition cable. Ensure that spark plug has good contact to ground.
Earlier working at cranking speed, eastward.g. checking pinch pressure, switch off ignition and disconnect connector "ii" from control unit of measurement.

Utilize of testers and testing units:

Only connect and disconnect secondary measuring sensor to corresponding ignition cables when vertical engine and ignition are switched off.
If the short-circuit protection is operated (cylinder comparison) and the engine stays upright, information technology is non possible to acquit the test with this exam instrument.
Do non connect test lamp to ignition scroll terminals 1 and 15.

Remove/install ignition coils

Shown on engine 112

5/i - Spark plug connector
five/3 - Screw
T1/ane - Cylinder 1 ignition coil
T1/ii - Cylinder 2 ignition curl
T1/iii - Cylinder 3 ignition curl
T1/4 - Cylinder four ignition gyre
T1/v - Cylinder 5 ignition coil
T1/6 - Cylinder vi ignition coil
T1/seven - Cylinder 7 ignition coil
T1/eight - Cylinder eight ignition curlicue

Arrow: Identification of the connector

Unclip cover on front side of engine
Remove engine cover with integrated air filter. The air filter is integrated in the engine embrace. Remove the engine cover or the air filter housing past pulling information technology from the cylinder head covers vertically in the upward direction.
Remove air filter housing.
Remove spiral (v/3). Remove Torx 30 bolts that hold down the scroll packs on the valve cover. I T30 commodities per ignition roll.
Detach spark plug connector (5/1) from the spark plugs. Pry off spark plug connector (5/ane) using open-stop wrench, double over the cylinder caput encompass of the spark plugs. Installation: Observe the identification of the connector (arrow) on the cylinder caput cover and the ignition curl of cylinders 1 to 6 or one to viii for the respective spark plug connector (5/1). Installing: put pressure on the ignition cablevision connector to push information technology all the fashion on the plug. Listen for a click as it goes on properly.
Split electrical connector of ignition coil of cylinder 1 to 6 (T1/ane to T1/6) or one to eight (T1/1 to T1/eight). Installation: Install new cable ties.
Remove ignition coil of cylinder i to 6 (T1/ane to T1/six) or 1 to 8 (T1/1 to T1/viii)
Install in the reverse society

Torque specification:

Bolt, ignition coil to cylinder head encompass (Engine 112, 113): eight Nm

A special spark plug cable removal tool is available (110 589 01 01 00). It is a 17mm, open concluded tool with a 25mm off-fix and is made by JTC with part number J-1308. It can be plant in eBay for $20.

Open-end wrench, double (110 589 01 01 00)

JTC Spark Plug Wire Removal Tool J-1308.

Supervene upon spark plugs

Shown on engine 112 in model 210

01 - Spark plug wrench
1 - Spark plug

Shown on ignition coil of engine 157.980

2 - Spark plug connector
3 - Safe lip

W220 replace spark plugs ignition coil.png

Put hood in service position. Button on the locks on the hinges at left side and and so the right side and raise hood to the service position (ninety degrees fully open up).
Remove ignition coils. Keep in correct society as the wire lengths are all unlike. Do not mix them up (mark with masking tape).
Blow out whatsoever dirt residue in the spark-plug recesses using compressed air
Remove spark plugs (1) using spark plug wrench (01) from cylinder heads. Utilise an air ratchet with a swivel extension and a 3/8" bulldoze 5/8" spark plug socket.
Spiral new spark plugs (1) using spark plug wrench (01) into cylinder heads. Start screwing new spark plugs by hand to avoid cantankerous threading.
Check spark plug connector (ii), ignition coils and ignition lines for damage, deformation and crack germination.
Grease rubber lips (3) of spark plug connectors (two) with spark plug connector grease (A0029898051) before installing
Install ignition coils

Always remove spark plugs on a stone cold engine or else risking stripping the threads.

Torque specifications:

Spark plugs (engine 112 and 113): 28 Nm

Cablevision length symbol on ignition cable connectors.

The valve cover has ignition coil and ignition cablevision annotations for each cylinder (cylinder 5 H-cablevision goes to a and G-cable goes to b).

Parts for ignition coil, ignition wire and spark plug replacement task

Swivel extension and spark plug socket. A regular 5/8" (15.8mm) spark plug socket with a rubber insert works well for removing spark plugs. All the same the surreptitious is to apply a variety of extensions e.yard., a curt 74mm iii/eight" drive extension on the tight spots in conjunction with a with hinge head.

In practice, spark plug jobs on M112 and M113 can be done by using pliers with bent olfactory organ for ignition plug removal and hinge wrench with short extension and spark plug socket

Swivel wrench with extension and spark plug socket in action (on M113)

Spark plugs and wires replacement (by Masood)

Spark plugs and wires replacement

How to replace spark plugs and wires

Spark plug connector grease

The prophylactic boot on the ignition cable is difficult to remove from a spark plug fifty-fifty when using the special removal tool. Solution is to employ a small quantity of dielectric grease to the top conductor and the ceramic insulator (or to the spark plug connector) when re-installing new plugs. This helps keep moisture away and stops corrosion. Makes information technology infinitely easier to remove the spark plug connector.

OE - A0029898051 (12 EUR)
BERU ZKF01 - 0890300029 (viii EUR)
Permatex 22058

Grease for spark plug adaptors (0029898051)

BERU ZKF01 grease for spark plug adaptors

Permatex 22058 Dielectric Tune-Upwards Grease

Parts

Spark plugs

Mercedes-Benz specifies replacement of plugs at every 100 000km or 4 years. Spark plug ignition cables don't concluding much longer than that either.
The resistance of the spark plug (electrode to ignition cable connector) is virtually 4.5K to 6K ohms.
There should be extremely high resistance between the electrode and the plug metal thread.
The spark plug electrode gap is 0.039" or 1mm.
Tightening torque for spark plugs is 20-30 Nm (28 Nm according to WIS).
One-time spark plugs can prove worn electrodes and a wider than specification gap.
Cleaved insulators are common during removal of seized OEM plugs.
Corroded spark plug threads make it difficult to remove an onetime plug. Solution is to utilize high temperature anti-seize grease (see beneath) when re-installing new plugs.

Part numbers:

OE - A0041591903
OE - A0031599403
OE - A0041595003 (15 EUR)
Bosch 0242230500 (5 EUR)
Denso PK16PRL11 (half dozen EUR)
Denso IK16TT (8 EUR) - recommended for LPG, up to 100 0000 km
NGK 4292 (EUR 8)
BRISK DR17YS-9 (EUR 3) - suited for LPG, interval max thirty 000 km

Ignition coils

It is possible to perform basic tests on an ignition coil using a digital multi meter (DMM). Each coil secondary resistance measured from the plug cable to any of the 3 pins in the input electrical connector is approximately 4.viii K Ω (Mega Ohms). The cable circuit is isolated from basis thus the resistance between the cable pin and basis is infinity Ohms or open up circuit.
For BOSCH ignition coils the production engagement is visible on the curl (21T008 means product year 2021).

Parts:

OE A0001587303 (replaced past A0001587803).
BOSCH 0221503035 (forty EUR)

Ignition curlicue (A0001587803)

T30 screw for attaching ignition roll to engine (A0019907212).

Ignition cables

Spark plug ignition cables take a limited life. The resistance element in the cables frequently fails or goes high resistance due to fatigue.

Cablevision lead insulation can break down causing arcing to ground. The resistance for new plug wire is approximately 2.18K ohms.

It is possible to perform basic tests on an ignition roll using a digital multi meter (DMM). Each coil secondary resistance measured from the plug cable to whatsoever of the 3 pins in the input electrical connector is approximately four.viii 1000 Ω (Mega Ohms). The cable circuit is isolated from ground thus the resistance between the cablevision pivot and footing is infinity Ohms or open excursion.

Ignition cables are in unlike lengths:

M-cable: 245mm - A1121500118 (45 EUR), BOSCH 0356912948 (fourteen EUR) - M112 x8, M113 x9
Chiliad-cable: 265mm - A1121500218 (45 EUR), BOSCH 0356912950 (14 EUR) - M112 x4, M113 x4
H-cable: 290mm - A1121500318 (56 EUR), BOSCH 0356912952 (30 EUR) - M112 x0, M113 x2 (If H-cable is not bachelor, a slightly longer L-cable can be used instead.)
Fifty-cable: 315mm - A1121500418 (56 EUR), BOSCH 0356912954 (32 EUR) - M112 x0, M113 x1