20.01 - Installation instructions: Coolant preheater A. Procedure, B. Parts ordering note Model 140

 

Modification: Engines 104.944/994 and 603.971 included

Installation instructions

Coolant preheater 20.1

Model 140

To prevent the engine from cooling off completely at low ambient temperatures, an electric coolant preheater can be retrofitted in a core hole of the engine block to keep the engine coolant warm or heat it up.

The coolant preheater is connected to the standard household current supplies via the existing plug on the unit.

The unit's power consumption is 500 W at a voltage of 220 V, 115 V option.

The installation instructions are subdivided into the following sections:

A. Procedures

a) Model 140.028 (engine 104.944)

Model 140.032/033 (engine 104.990)

Model 140.032/033 (engine 104.994)

b) Model 140.042/043 (engine 119.971), 140.050/051 (engine 119.970)

c) Model 140.056/057 (engine 120.980)

d) Model 140.134 (engine 603.971)

B. Parts ordering note

Special tools

119 589 00 09 00

119 589 00 03 00

001 589 66 21 00

124 589 15 21 00

A. Procedures

a) Model 140.028 (engine 104.994)

Model 140.032/033 (engine 104.990)

Model 140.032/033 (engine 104.994)

1 Disconnect the ground cable from the battery.

2 Remove, install the lower engine compartment insulation panels (Maintenance Manual Volume 3, Operation item 6190).

3 Drain all coolant (RA 20-0100).

P20-5066-13

4 Unscrew the screw plug (b) from the right side of the engine block.

Special tool 119 589 00 09 00.

5 Place O-ring on the coolant preheater, then thread it into the engine block and tighten.

Tightening torque: 70 Nm.

P20-5229-13

6 Use two hexagon bolts (M6x15) with two washers (5) to mount the heat shield (6) above the coolant preheater; attach the clamp (3) for the electrical wiring at the same time.

7 Route the wiring from the coolant preheater along the right side of the block and toward the front of the vehicle along the main cable harness (alternator), then bind the two leads together with cable straps (arrows).



Ensure that the electrical wire and the main cable harness remain as far as possible from the exhaust manifold. Route the wiring so as to avoid chafing points.

P20-5228-13

8 Continue installation of the electrical lead by attaching it to the air pump's output hose with a clamp (7). Then route the wire toward the front of the vehicle, along the vacuum line and to the right side member. Use the factory-installed cable straps to attach.



Always ensure that adequate distance is maintained between the electrical wiring and the belts and pulleys.

9 Remove, install the right headlamp

(RA 82-052).

P20-5227-13

10 Run the electrical lead beneath the expansion reservoir hose to the radiator. Continue by routing the lead by the washer reservoir filler neck and along the right side member to the front cross member. Then secure the lead with cable straps (arrows).


Route wiring so as to avoid chafing points.

11 Shorten the edges of the spring clamp (13) by 5 mm.

P20-5233-13A

12 The spring clamp (13) and protective cap (12) are attached to the front cross member with two sheetmetal screws. Position the spring clamp at a distance of approx. 140 mm (dimension a) and drill two holes with a 3 mm dia. bit (consult mounting diagram).



Ensure that the spring clamp (13) does not rub against the grille when the hood is closed with the plug attached.

Apply a coat of zinc-dust paint to the holes.

P20-5034-13

13 Mount the spring clamp.

Mounting diagram

12 Protective cap
13 Spring clamp
14 Screw (B3.9 x 9.5)
15 Washer (A4.3)

14 Reconnect the battery ground cable.

P20-0037-13

15 Refill the cooling system with coolant
(RA 20-0100).

16 Check the cooling system for leaks
(RA 20-0170).

Special tool 124 589 15 21 00.

b) Model 140.042/043 (engine 119.971), 140.050/051 (engine 119.970)

1 Disconnect the ground cable from the battery.

P20-5239-13

2 Remove, install the lower engine compartment insulation panels (Maintenance Manual Volume 3, Operation item 6190).

3 Drain all coolant (RA 20-0100).

4 Unscrew the screw plug from the left side of the engine block.

Special tool 119 589 00 09 00.

5 Place O-ring on the coolant preheater, then thread it into the engine block and tighten.

Special tool 119 589 00 03 00.

Tightening torque: 70 Nm.

P20-5226-13

6 Route the electrical lead from the coolant preheater upward and along the knock-sensor wire to the left wheelhousing, then secure it with cable straps (arrows).


Ensure that the electrical wiring is installed as far as possible from the exhaust manifold.

P20-5225-13

7 Remove, install left headlamp (RA 82-052).

8 Continue installation of the electrical lead by attaching it to the left wheel carrier with the Omega clamp, which replaces the factory-installed clamp.

P20-5224-13

9 Run the electrical lead along the auxiliary fan's cable harness and to the front cross member; attach with cable straps (arrows).



Route wiring so as to avoid chafing points.

10 Shorten the edges of the spring clamp (13) by 5 mm.

P20-5240-13

11 The spring clamp (13) and protective cap (12) are attached to the front cross member with two sheetmetal screws. Position the spring clamp at a distance of approx. 150 mm (dimension a) and drill two holes with a 3 mm dia. bit (consult mounting diagram).



Ensure that the spring clamp (13) does not rub against the grille when the hood is closed with the plug attached.

Apply a coat of zinc-dust paint to the holes.

P20-5034-13

12 Mount the spring clamp.

Mounting diagram

12 Protective cap
13 Spring clamp
14 Screw (B3.9 x 9.5)
15 Washer (A4.3)

13 Reconnect the battery ground cable.

P20-0037-13

14 Refill the cooling system with coolant
(RA 20-0100).

15 Check the cooling system for leaks
(RA 20-0170).

Special tool 124 589 15 21 00.

c) Model 140.056/057 (engine 120.980)

1 Disconnect the ground cable from the battery.

2 Remove, install the lower engine compartment insulation panels (Maintenance Manual Volume 3, Operation item 6190).

3 Drain all coolant (RA 20-0100).

P20-5238-13

4 Unscrew the screw plug (a) from the right side of the engine block.

Special tool 119 589 00 09 00.

5 Place O-ring on the coolant preheater, then thread it into the engine block and tighten.

Tightening torque: 70 Nm.

P20-5294-13

6 Use a collar clamp to attach the wire from the coolant preheater to the right side of the engine block above the starter. Run the wire behind the starter and downward.



Ensure that the electrical wiring is installed as far as possible from the exhaust manifold.

Route the wiring so as to avoid chafing points.

1 Coolant preheater

2 O-ring

3 Collar clamp

4 Hexagon bolt (M6 x 12)

5 Washer A6.4

P20-5236-13

7 Continue installation of the electrical lead by routing it toward the front along the main cable harness to the alternator; attach the wire to the cable with cable straps (arrows).

P20-5235-13A

8 Run the electrical lead upward to the right side member, then attach it to the air pump ducts with one collar clamp each (7).



Always ensure that adequate distance is maintained between the electrical wiring and the belts and pulleys.

9 Remove, install right headlamp (RA 82-052)

P20-5234-13

10 Run the electrical lead along the right wheel carrier and beneath the expansion reservoir hose to the radiator. From the washer reservoir filler neck, continue by routing the wire to the front cross member. Secure the wire with cable straps (arrows).



Route wiring so as to avoid chafing points.

11 Shorten the edges of the spring clamp (13) by 5 mm.

P20-5233-13

12 The spring clamp (13) and protective cap (12) are attached to the front cross member with two sheetmetal screws. Position the spring clamp at a distance of approx. 140 mm (dimension a) and drill two holes with a 3 mm dia. bit (consult mounting diagram).



Ensure that the spring clamp (13) does not rub against the grille when the hood is closed with the plug attached.

Apply a coat of zinc-dust paint to the holes.

P20-5034-13

13 Mount the spring clamp.

Mounting diagram

12 Protective cap

13 Spring clamp

14 Screw (B3.9 x 9.5)

15 Washer (A4.3)

14 Reconnect the battery ground cable.

P20-0037-13

15 Refill the cooling system with coolant
(RA 20-0100).

16 Check the cooling system for leaks
(RA 20-0170).

Special tool 124 589 15 21 00.

d) Model 140.134 (engine 603.971)

1 Disconnect the ground cable from the battery.

2 Remove, install the lower engine compartment insulation panels (Maintenance Manual Volume 3, Operation item 6190).

3 Drain all coolant (RA 20-0100).

P20-5108-13

4 Unscrew the screw plug (b) from the right side of the engine block.

Special tool 119 589 00 09 00.

5 Place O-ring on the coolant preheater, then thread it into the engine block and tighten.

Tightening torque: 70 Nm.

P20-5391-13

6 Use two hexagon bolts (M6x15) (3) to mount the heat shield (4) above the coolant preheater.

7 Use cable straps to mount the electrical lead of the coolant preheater to the main cable harness of the alternator.



Route wiring so as to avoid chafing points.

1 Coolant preheater

2 O-ring

3 Hexagon bolts (M6x15)

4 Heat shield

P20-5389-13

8 Continue installation of the electrical lead by attaching it to the alternator main cable harness and fasten with cable straps (arrows).

P20-5394-13

9 Continue attaching the electrical lead to the alternator main cable harness and the hot water hose (arrows) using cable straps.



Route wiring so as to avoid chafing points.

10 Remove, install the right headlamp
(RA 82-052).

P20-5393-13

11 Replace the previous clamp (a) by new clamp part no. 000 995 72 44.

Run the electrical lead beneath the expansion reservoir hose to the radiator. Continue by routing the lead by the washer reservoir filler neck and to the front cross member. Then secure the lead with cable straps (arrows).


Route wiring so as to avoid chafing points.

12 Shorten the edges of the spring clamp (13) by 5 mm.

P20-5233-13A

13 The spring clamp (13) and protective cap (12) are attached to the front cross member with two sheetmetal screws. Position the spring clamp at a distance of approx. 140 mm (dimension a) and drill two holes with a 3 mm dia. bit (consult mounting diagram).



Ensure that the spring clamp (13) does not rub against the grille when the hood is closed with the plug attached.

Apply a coat of zinc-dust paint to the holes.

P20-5034-13

14 Mount the spring clamp.

Mounting diagram

12 Protective cap

13 Spring clamp

14 Screw (B3.9 x 9.5)

15 Washer (A4.3)

15 Reconnect the battery ground cable.

P20-5392-13

16 Refill the cooling system with coolant
(RA 20-010).

17 Check the cooling system for leaks
(RA 20-017).

Special tool 124 589 15 21 00.

B. Parts ordering note

Consult the parts documentation for information on the parts required for installation:

The following additional parts are also required:

Model 140.028/032/033

Model 140.042/043/050/051

Model 140.056/057

Model 140.134