Thermostat: Service and Repair

WM 195819 Removing and installing coolant regulator (thermostat) on 4.8-litre DFI engines

Tools





Technical values






Preliminary work

1. Drain the cooling system. => 193817 Draining and filling with coolant on DFI engines (includes bleeding) - section on "Draining"
2. Remove coolant pump. => 195019 Removing and installing coolant pump on DFI engines - section on "Removing" -1 coolant pump and 2 intake sockets-





Thermostat with transfer pipe when installed

Information

Component overview





Thermostat housing









Water pump and thermostat insert






Removing coolant regulator

1. With engine installed: Remove thermostat insert using shop-made tool.
1.1. Use pointed-nose pliers to wrap a piece of wire or electric cable through the transfer pipe and around two opposite brass spokes of the thermostat insert. => Removing thermostat with wire loop (tool setup when removed)





Removing thermostat with wire loop (tool setup when removed)





1.2. Tie a knot in the wire or electric cable to prevent it from being pulled out. => Removing thermostat with wire loop (tool setup when removed)

CAUTION

Pointed or sharp objects

- Risk of cracks, pricks or cuts

-> Wear personal protective gear.

1.3. Pull intake socket/transfer pipe and the thermostat insert out of the crankcase completely using an inserted screwdriver or pliers. => Removing thermostat with wire loop (tool setup when removed)
2. With engine removed: Remove intake socket/transfer pipe.
2.1. To do this, reach into the intake socket using a commercially available internal puller (46 to 56 mm) internal puller Nr.108 Pos.6 and brace it carefully. -1-





Internal puller inserted in intake socket

2.2. Remove intake socket with the internal puller. -arrow-





Pulling out intake socket

2.3. Use a hook or assembly tool T10118 to reach into the brass spokes of the thermostat insert and pull it out. => Removing thermostat insert





Removing thermostat insert

Installing coolant regulator

Information

- The seals on the intake socket must be replaced.

Information

Damaged thermostat inserts must be replaced.

Information

- 000 043 204 68 (Status 02/07) "Kluber Syntheso GLEP 1" is a neutral-reaction assembly grease that can be used for connection pieces and sealing rings in oily or water-carrying areas.

- Use "Kluber Syntheso GLEP 1" very sparingly. Components and lubrication points must only be coated lightly and excess grease must be removed. Excess grease can result in leaks.

- "Kluberplus S06-100" is a water-soluble assembly gel with the number 000 043 205 93 (status 06/08). This must always be used for the sealing rings on the intake socket between the water pump and thermostat housing. It must be diluted 50:50 with water.

1. Lubricate the sealing ring for the thermostat insert and the two sealing rings for the intake socket sparingly with "Kluberplus S06-100" assembly gel 000 043 205 93 (status 06/08).
2. Push thermostat insert through the opening in the crankcase and into the thermostat housing. => Inserting thermostat insert





Inserting thermostat insert

3. Check that the thermostat insert is straight and is fitted as far as it will go. => Checking thermostat insert





Checking thermostat insert

4. Fit transfer pipe/intake socket. Check that sealing rings coated lightly with Kluberplus S06-100 are at the correct installation position (sealing rings must not be installed the wrong way round). -1-





Fitting transfer pipe/intake socket

5. Check that the transfer pipe is inserted as far as it will go. You must not be able to feel any overhang or underhang between the transfer pipe and crankcase. The transfer pipe must be flush. => Transfer pipe/intake socket fully inserted





Transfer pipe/intake socket fully inserted

Subsequent work

1. Install coolant pump. => 195019 Removing and installing coolant pump on DFI engines - section on "Installing"
2. Fill cooling system. => 193817 Draining and filling with coolant on DFI engines (includes bleeding) - section on "Filling"