Mercedes W163 ML500 ML350 Water Pump, Thermostat, Tensioner, Idler Pulley FULL DIY also M112, M113

This video is a full DIY for the water pump, thermostat, tensioner and idler pulley on Mercedes Benz M112 and M113 engines. The job shows this work on a W163 2005 ML500 and applies to other models with the M112 (V6) or M113 (V8) engines. Check the Pinned Comment for more information.

Timestamps, Part Numbers, Torque Values, other relevant Video Links:
00:23 Diagnostics and overview
04:00 Two different Water pumps - how to determine your pump type
05:35 Disconnect battery (for models with an
electric fan)
06:00 Drain the coolant (7mm)
07:56 Remove fan shroud fasteners (10mm)
09:05 Disconnect the upper radiator hose (7mm)
10:14 Disconnect the electric fan for models so equipped (10mm, 13mm)
11:34 Remove oil dipstick
11:45 Notes if you have a fan clutch (36mm,
counterclockwise to loosen)
Link to the Fan Clutch Video mentioned:
   • Mercedes ML350 Remove Fan & Fan Clutc...  

13:08 Remove or lower the fan shroud
15:08 Loosen the four water pump pulley bolts
(10mm)
15:38 Remove the belt (17mm feature, turn
counterclockwise)
18:20 Remove the secondary air pump (optional step,
E10)
19:23 Remove the thermostat (E10)
21:56 Remove MAP sensor bracket (E10)
23:12 Remove the idler pulley (T50, part INA
5320160100 or MB A000-202-09-19)

23:53 Make a water pump bolt template
25:11 Remove the alternator bolt (E14)
25:46 Disconnect the hose at the water pump from aux coolant pump
(7mm)
27:38 Disconnect the oil cooler hose (for models so equipped)
28:20 Remove the 14 remaining water pump bolts:

- there are four E12 bolts and ten E10 bolts remaining
- place each fastener in the correct spots on your
bolt template
31:56 Remove the water pump from the timing case cover
33:58 Remove the water pump gasket and clean
the gasket surface and bolt holes
37:02 Repair any electrical wire wrap (if needed)

37:42 Swap the hose(s) from the old pump to the new
pump and inspect the new pump:
- I use a Graf PA710 for this ML500 with the oil
cooler
- MB part for the pump with oil cooler output:
112-200-14-01-80
- MB part for pump without oil cooler output: 112
-200-15-01-80

45:40 Swap the upper radiator hose from the old
thermostat to the new thermostat (Wahler, MB
112-203-02-75)

47:06 Place the new gasket and water pump on
the timing case cover and tighten the 14 bolts just hand tight
51:25 A note about the WIS torque values ("pre-
tapped" v "not pre-tapped")
53:29 Torque the 14 bolts in several passes to the
following final torque values:
- the ten E10 bolts: 10 Nm (88 inch-lbs, 7.3 ft-lbs)
- the four E12 bolts: 25 Nm (221 inch-lbs, 18.5 ft-
lbs)

58:12 Reconnect the hoses to the water pump
59:07 Install the idler pulley: torque is 20 Nm (177
inch-lbs, 14.7 ft-lbs)
59:31 Install the alternator bolt: torque is 42 Nm
(31 ft-lbs)
59:56 Install the two bolts for the MAP sensor
bracket (no torque value - just snug)
01:00:22 Install the water pump pulley bolts: you can either
torque them now or wait until you have the bolt
on to hold the pulley; torque is 9Nm (80 inch-lbs)
for the M112 engine and 10 Nm (88 inch-lbs) for
the M113 engines

01:00:53 Reconnect coolant temperature sensor
01:01:03 Install the thermostat with new gasket:
torque is 14 Nm (124 inch-lbs) for the M112 engines and 10 Nm (88 inch-lbs) for the M113 engines
01:02:46 Install the secondary air pump: torque is 12 Nm (106 inch-lbs)
01:03:57 Remove & replace belt tensioner - this step is optional:
- part number is Liten 950-113 or MB 112-200-09-70
- install torque on the two E12 bolts is 25 Nm (18.5 ft-lbs, 221 inch-lbs)

01:09:22 Install the belt (belt routing diagram is shown)
01:13:30 Tighten the water pump pulley bolts (if you haven't already - torque is 10 Nm on the M113; 9 Nm on the M112)
01:13:41 Reinstall the fan shroud
01:15:09 Install the fan, fan clutch (for models without electric fan) - refer to the Linked Video below:
   • Mercedes ML350 Remove Fan & Fan Clutc...  

01:15:20 Install the fan shroud fasteners
01:15:54 Reconnect the lower and upper radiator hoses to the radiator
01:16:48 Reconnect the electric fan wires
01:17:40 Reinstall the oil dipstick

01:17:46 Begin the coolant refill - notes about coolant types; you will need at least 2.5 gallons (my final/full refill was 2.6 gallons, or 10L on this M113)

01:20:43 Pour coolant into the expansion tank; squeeze the upper and lower radiator hose to aid the air bleeding process. Expect to add about 8.0 - 8.8L (2.1 - 2.3 gallons) of coolant before starting the engine.

01:22:16 Reconnect battery (for models with electric fan)

01:22:40 Start the engine to begin the full bleed
01:28:32 Check for leaks and top off at needed after a few drives

Links:
Oil Cooler Seals, Oil Filter Housing, and Pressure Port gasket replacement:
   • Mercedes ML500 Oil Cooler and Filter ...  

Fan removal and replacement:
   • Mercedes ML350 Remove Fan & Fan Clutc...  

I hope this video was helpful for you. Thanks for watching, and good luck with your repair!