Mercedes W163 DIY Valve Cover Gasket & Breather Cover Reseal Both Sides M112 M113 ML350 ML500 ML320

This is a step-by-step DIY video which shows how to replace the valve cover gaskets and reseal the breather covers on the Mercedes M112 and M113 engines, as found in the W163 (ML Class), W220, W210 and other V6 and V8 models ('98 - '06). Shown in the video are both an '05 ML500 (M113) and an '03 ML350 (M112).

Major Timestamps (see the Pinned Comment for more detailed Timestamps):
00:23 Diagnostics
02:00 Parts

Begin Right side Valve Cover Job
03:20 Right side valve cover gasket and notes on gasket fit
04:11 Remove air filter box
06:36 Remove bolts for air duct, ATF dipstick (10mm, E10)
07:26 Disconnect left side hose to air duct
08:34 Remove air duct
13:01 Disconnect ignition coil electrical connectors
13:52 Disconnect right side breather hose
14:13 Remove ignition coil bolts (T30)

Remove Right side Breather Cover
16:04 Shown on the V6: Remove two breather cover screws (T25 or H4)
17:14 Break free all valve cover bolts (E10) before removing the two long bolts
18:52 Remove breather cover

Remove Right side Valve Cover
21:00 Back to the V8 -- tips for removing the damaged fasteners
21:50 Break free all the valve cover bolts first
23:58 Remove valve cover from the head
26:11 Clean the head surface after removing the valve cover

Right side Valve Cover on the Bench
27:19 Clean and inspect valve cover
27:55 Inspect breather passages on the cover
29:07 Clean breather cover and mating surface
31:04 Inspect old valve cover gasket
31:31 Install new valve cover gasket
33:32 Clean valve cover bolts
33:58 Clean valve cover mating surface on the head

Right side Valve Cover Installation and Breather Cover Re-seal
33:58 Clean valve cover mating surface on the head
35:00 Place valve cover on the head and thread in a few bolts by hand
36:28 Check gasket before installing all the bolts
37:40 Cut RTV nozzle for breather cover RTV application (thin 2mm bead)
39:34 Apply RTV into the channel on breather cover (thin 2mm bead)
41:51 Install breather cover to valve cover
43:02 Tighten all the valve cover bolts (final torque 80 inch-lbs; tighten the bolts in several passes, starting at the center on each pass and spiraling top/bottom out towards the ends)
45:36 Install ignition coil bolts (torque: 70 inch-lbs)
46:27 Connect ignition coil electrical
47:01 Move auxiliary coolant pump back into place

Removing Breather Hoses, right and left side
47:12 Replace breather hoses, air distribution piece
48:21 How to remove a broken air distribution tube from the throttle body
54:35 Remove the hose connectors to re-use them

Begin Left side Valve Cover Job
56:01 Left side valve cover overview
56:33 Depressurize fuel system using Schrader valve
59:56 Disconnect fuel line (17mm)
01:02:52 Disconnect left side breather hoses
01:04:32 Disconnect the ignition coil electrical
01:05:48 Remove fuse box heat shield (two Philips screws)
01:06:27 Remove ignition coil bolts (T30)

Remove Left side Breather Cover
01:08:02 Remove breather cover screws (T25 if aluminum, H4 if stainless)
01:08:45 Break free the valve cover bolts (E10)
01:11:20 Remove breather cover E10 bolts
01:11:32 Remove/dislodge breather cover from valve cover
01:13:46 Remove remaining valve cover bolts (E10)
01:14:37 Remove valve cover from the head
01:17:08 Inspect, clean head

Left side Valve Cover on Bench
01:18:14 Remove old valve cover gasket, clean the surfaces
01:22:52 Install new valve cover gasket

Install the Left side Valve Cover and Re-seal the Breather Cover
01:24:08 Clean gasket surface
01:24:29 Install valve cover perimeter bolts hand-tight
01:25:15 Apply RTV to breather cover channel, bolt holes (thin 2mm bead)
01:27:10 Install breather cover to valve cover
01:27:39 Install new breather cover screws (H4, low torque, torque: 35 inch-lbs)
01:28:55 Tighten all valve cover bolts (torque: 80 inch-lbs)
01:31:28 Install ignition coil bolts (T30, torque is 70 inch-lbs)
01:32:27 Connect ignition coil electrical
01:32:49 How to replace the coil electrical connector (MB A203 545 2038)
01:38:50 Reconnect fuel line (17mm, torque: 28 ft-lbs)

Install Breather Hoses and Air Duct Hoses
01:39:45 Disassemble left side hoses and remove hose connector
01:41:15 Connect new left side hoses together
01:41:52 Inspect air distribution piece/hose tee, new design
01:42:08 Connect hoses to the air dist piece
01:43:40 Install new breather hoses as a unit
01:47:18 Notes on air duct gasket (use MB A112 159 0080 for the W163 throttle body)
01:48:53 Install air duct but don't connect it yet (very tight fit on the V8)
01:54:04 Install air duct breather hose
01:55:21 Connect air duct to the throttle body
01:57:03 Install bolts for the air duct (E10) and ATF dipstick (10mm)
01:57:19 Install air hose and filter box
02:00:34 Prime fuel system

See the Pinned Comment for all part numbers. I hope this video is helpful.
Thanks for watching, and good luck with your repair!