SV6 3.6 Thermostat Replacement

[wb1986]

Hey there,
Just wanted to pick everyones brain about replacing the thermostat on my VZ commodore.

Ive managed to find the procedures from the holden service manual for removing the intake manifold, and also for flushing the radiator from these forums. Just need to know if i required any special tooling (from what Ive heard, i might need torx bits), an just any info i can gather in general really.

Seems to be a simple enough job, just time consuming. Any advice, or if someone has a copy of the procedure for replacing the thermostat, would be just awesome.

Quote to repair from my Holden dealer was in the vicinity of around $900!

[Benboy]

REMOVE THERMOSTAT FROM VZ V6

1. Disconnect the battery earth lead, then remove the engine covers and radiator top cover.

2. Drain the cooling system and then remove the itake manifld assembly. Make sure to plug the inlet ports to prevent entry of dirt etc.

3. Remove the coolant inlet pipe.
(a) Remove the radiator from the end of the inlet pipe, then remove the pipe to alternator bracket retaining bolt.
(b) Remove the bolt retaining the inlet pipe to the thermostat housing, then remove the inlet pipe from underneath the vehicle.

4. Disconnect two heater hoses.

5. Disconnect the engine harness and lay it out of the way.
(a) Disconnect engine coil packs for cylinders 2, 4 & 6.
(b) Disconnect coolant temperature sensor.
(c) Disconnect the pre-O2 sensor connectors.
(d) Remove the engine harness ground terminal bolt from the cylinder block, then release the retaining clips for the harness mounting bracket.
(e) Disconnect the engine to transmission harness connector located at the rear of the engine.
(f) Remove the two bolts securing the harness mounting bracket to the rear of the engine.
(g) Carefully lift harness assembly and place out of the way on the right side of the engine.

6. Remove the bolts securing the heater pipe to the right hand side of the cylinder head, then remove the heater pipe assembly.

7. Remove the bolts and grommets securing the thermostat housing then remove the assembly from the vehicle.

INSTALL THERMOSTAT INTO VZ V6

Note: always replace all gaskets and O-rings with new ones on assembly.

1. Clean the thermostat housing surgaces.

2. Install thermostat and housing using a new gasket then tighten retaining bolts to specifications.
THERMOSTAT HOUSING BOLTS..........10NM

3. Install the heater pipe assembly into position using new O-rings then tighten retaining bolts to specifications.
HEATER PIPE TO THERMOSTAT HOUSING..........10NM
HEATER PIPE TO CYLINDER HEAD..........35NM

4. Install the electrical harness.
(a) Carefully position the harness assembly into place on the engine.
(b) Instal the two bolts securing the harness mounting bracket to the rear of the engine.
HARNESS BRACKET BOLTS..........15NM
(c) Install the engiine harness ground terminal bolt to the cylinder block, tightening to specifications.
GROUND TERMINAL BOLT..........12NM
(d) Reconnect all dosconnected electrical connections, ensuring retaining clips are secured properly.

5. Reconnect the two heater hoses.

6. Install the coolant inlet pipe into position then install and tighten the inlet pipe retaining bolts and reconnect radiator hose.
PIPE TO THERMOSTAT HOUSING..........23NM
PIPE TO ALTERNATOR BRACKET.........25NM

7. Reconnect engine coil packs,

8. Install the intake manifold system using new gasket. Ensure that retaining bolts are tightened in correct sequence and to specifications.

9. Fill the cooling system ensuring that all air is bled/excluded from system.

10. Install the engine covers and radiator top cover, then reconnect battery earth lead.

11. Run engine and check for water leaks.

[wb1986]

perfect! exactly what i was looking for. Thanks alot for that benboy.

[sirjolly18]

Mate great help.
removed my thermostat on the weekend as it was leaking, Replaced the seal with a metal gasket and it leaked even more. Got a paper gasket from auto 1 and some aviation gasket sealant and no worries. The Torque settings really helped mate. i cracked one of the thermostat bolts but was luckey to remove it so got myselft a torque wrench and job done. i got some pictures to post to show everything

[Jordanlewis]

What did you guys find the access to the thermostat like? Can it be done from underneath without removing the gearbox? I've just tried to tighten mine up (as i think its leaking) from the top (removing the intake manifold) and I cant get to the bottom bolt! How have people managed this?

[VZ_SS]

Read the first post. Pretty comprehensive mate.