Alloytec thermostat

[azazeldeath]

I tried the search feature no how-to's.

I want to replace the thermostat, I know it is at the back of the engine, but how is the best way to replace it? Would like to do it without removing the engine if possible.

[petergl67]

Can be done. I'm not 100% but I herd trans has to be dropped. Don't take my advise though cause I don't know it if was for ur model or a different one. It is hard to get to and Holden made something that may need to be changed regualy so hard to get to. I know mechanics charge around $80 tops to do. While it's getting done may ad well but a aftermarket one that will open up earlier than the original to keep engine cooler which in the long run means less engine wear

[richardpalinkas]

actually, mechanics charge 900 for it, best way is to remove the manifold, and them remove all wiring harness out of the way

[VZCALAIS190]

No need to remove the tranny, removing the intake manifold will give you enough room to get to it might take you several hours to do but beats removing the transmission. Good luck.

[azazeldeath]

I will try do up a how-to with pictures once the part arrives. Thanks

[exastra]

I am pretty sure I have the instructions to do a thermostat. I'll have alook and get back to you. I'm sure you pull the manifold off and then you can get access to it.

[azazeldeath]

If you have some it will be great. I have a few weeks for the parts to arrive anyway. Holden, sometimes they are good, other times you just hate them with a passion.

[exastra]

Hi, did you replace your thermostat yet? I couldn't find the procedure for a VZ but found one for a VE and it mentions dropping the motor and transmission so you can get at it. If you read this thread;
Need help! Ve omega thermostat change
there is a post how someone replaced theirs by removing the inlet manifold.

Below is the prosedure I found but it is for VE (I think) - YUK!

Removal Procedure
Caution: Refer to Battery Disconnect Caution in the Preface section.
1. Disconnect the battery negative cable. Refer to Battery Negative Cable Disconnection and
Connection.
2. Remove the air inlet grille panel. Refer to Air Inlet Grille Panel Replacement.
3. Remove the engine cover. Refer to Engine Cover Replacement.
4. Remove the air cleaner inlet duct. Refer to Air Cleaner Inlet Duct Replacement.
Caution: Refer to Radiator Cap Removal Caution in the Preface section.
5. Ensure the engine temperature is below 50°C before removing the radiator cap.
Caution: Refer to Safety Glasses Caution in the Preface section.
Caution: Refer to Vehicle Lifting Caution in the Preface section.
6. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.
Important: Store used coolant in the correct manner, such as in a used engine coolant holding
tank. Do not pour used coolant down a drain. Ethylene glycol antifreeze is a very toxic chemical. Do
not dispose of coolant into the sewer system or ground water. This is illegal and ecologically
unsound.
7. Drain the cooling system. Refer to Cooling System Draining and Filling.
Important: Do Not separate the upper and lower intake manifolds.
8. Remove the lower intake manifold. Refer to Lower Intake Manifold Replacement.
Important: Ensure material used to cover cylinder head inlet ports is lint free to prevent any
foreign matter entering the ports.
9. Cover the exposed cylinder head inlet ports.
Raise the securing lock (3) from the radiator support bracket (2) by 10 mm on both sides.
11. Remove the radiator support bracket (2) from the radiator slide pin assembly (1) on both sides.
12. Remove the front air deflector. Refer to Front Air Deflector Replacement.
13. Remove the engine splash shield if equipped. Refer to Engine Splash Shield Replacement.
14. Remove the engine coolant inlet pipe. Refer to Engine Coolant Inlet Pipe Replacement.
15. Remove the exhaust system. Refer to Exhaust System Replacement.
16. Remove the propeller shaft. Refer to Propeller Shaft Replacement.
Important: The front wheels of the vehicle must be maintained in the straight ahead position and
the steering column must be in the LOCK position before disconnecting the steering column or
intermediate shaft. If these procedures are not followed, incorrect alignment of some components
during installation will result and damage to the SIR coil assembly will occur.
Important: Observing the orientation of the intermediate steering shaft (1) with reference to the
pinion shaft (3) will minimise the potential of incorrect steering column assembly alignment.
17. Mark the intermediate steering shaft (1) in relation to the pinion shaft (3).
Important: Bolts with micro-encapsulated thread sealant must be discarded after removal.
18. Remove the intermediate shaft to pinion shaft retaining bolt (2).
Discard the bolt.
19. Disconnect the intermediate shaft (2) from the pinion shaft (3).
Important: Step 20 to 35 detail how to use the engine and transmission 65 mm drop tool. If this
procedure is known, go to Step 36.
20. Using special tool EN-48536 lower the engine and transmission assembly 65 mm.
Important: The engine mounts must NOT bend or deflect from the vertical position, damage to the
mount will occur.
21. Support the power train with a suitable jack or table.
Remove the transmission support to body retaining bolts (1).
Remove the front and rear sub frame to front chassis rail retaining bolts (1).
Important: Do not tighten the bolts at this stage.
24. Replace the front and rear sub frame to body retaining bolts with four (M16 x 2.0) 160 mm bolts
from special tool kit EN-48536 .
25. Install the bolts until 2 mm of the thread remains visible below the sub frame.
Replace the transmission support to body retaining bolts with the two (M10 x 1.5) 115 mm bolts (2)
from special tool kit EN-48536 adjacent to each other. e.g. Left hand front and Right hand rear.
27. Install the bolts until 65 mm of bolt remains visible (A) between the bolt heads (2) and the
transmission mount (1)
Remove the centre sub frame to body retaining bolts (1).
29. Lower the power train slowly until the sub frame and transmission assembly is resting on the bolt
heads.
Insert the 65 mm spacer blocks (1) between the sub frame (2) and chassis rails (3).
Notice: Refer to Fastener Notice in the Preface section.
31. Tighten the front and rear sub frame retaining bolts.
Tighten
Tighten the bolts to 95 N·m (70 lb ft).
32. Install the remaining two (M16 x 2.0) 115 mm centre sub frame to body retaining bolts from special
tool kit EN-48536 .
Tighten
Tighten the bolts to 95 N·m (70 lb ft).
Position the engine support plate (1) to the front sub frame.
34. Install the four (M8 x 1.25) 28 mm engine support plate to front sub frame retaining bolts (2) from
special tool kit EN-48536 .
Tighten
Tighten the bolts to 10 N·m (89 lb in).
35. Support the transmission with a suitable jack or table.
Disengage the heater hose quick connect fitting retaining clip (3) with a suitable screwdriver.
37. Detach the heater hoses (1) from the heater pipes (2).
Remove the heater pipe assembly to cylinder head retaining bolt (3).
39. Remove the heater pipe assembly to engine coolant thermostat housing retaining bolts (5).
40. Remove the heater pipe assembly (4) from the cylinder head (2) and engine coolant thermostat
housing (1).
41. Remove the heater pipe assembly to engine coolant thermostat housing O-ring seals (6).
Important: The engine coolant thermostat housing has one longer bolt which is located in the
upper left of the housing.
42. Remove engine coolant thermostat housing to cylinder head retaining bolts (4) and plastic
retainers (3).
43. Remove engine coolant thermostat housing (2).
Important: Always replace the engine coolant thermostat housing to cylinder head gasket (1).
44. Remove engine coolant thermostat housing gasket (1).
Installation Procedure
Assemble the engine coolant thermostat housing to cylinder head retaining bolts (4), plastic
retainers (3) and engine coolant thermostat housing gasket (1) to the engine coolant thermostat
housing (2).
2. Install engine coolant thermostat housing (2) to the cylinder head and tighten the engine coolant
thermostat housing to cylinder head retaining bolts (4).
Tighten
Tighten the bolts to 10 N·m (89 lb in).
Important: Ensuring new O-ring seals (6) are fitted to the heater pipe assembly (4).
3. Install the heater pipe assembly to engine coolant thermostat housing O-ring seals (6) to the heater
pipe assembly (4).
4. Install the heater pipe assembly (4) to the cylinder head (2) and engine coolant thermostat
housing (1).
5. Install the heater pipe assembly to engine coolant thermostat housing retaining bolts (5).
Tighten
Tighten the bolts to 9 N·m (80 lb in).
Install the heater pipe assembly to cylinder head retaining bolt (3).
Tighten
Tighten the bolts to 35 N·m (26 lb ft).
Caution: Refer to Installing Hoses without Twists or Bends Notice in the Preface section.
Important: Make sure the heater hose quick connect fitting retaining clip is securely engaged into
the heater hose quick connect fitting (3).
7. Attach the heater hoses (1) to the heater pipes (2).
Important: Step 9 to 20 detail how to use the engine and transmission 65 mm drop tool. If this
procedure is known, go to Step 21.
8. Remove the four (M8 x 1.25) 28 mm engine support plate to front sub frame retaining bolts (2).
9. Remove the engine support plate (1) from the front sub frame.
10. Loosen the six sub frame to front chassis rail retaining bolts (1 and 2) by one turn each.
11. Remove the 65 mm spacer blocks from between the sub frame and chassis rails.
12. Raise the power train slowly until the sub frame and transmission mount are lifted off the bolt heads
and the power train is positioned back up into the engine bay.
13. Remove the centre (M16 x 2.0) 115 mm sub frame to front chassis rail retaining bolts (1).
14. Install the original centre sub frame to front chassis rail retaining bolts (1).
Tighten
Tighten the bolts to 160 N·m (118 lb ft).
15. Tighten the front sub frame to front chassis rail retaining bolts.
Tighten
Tighten the bolts to 160 N·m (118 lb ft).
16. Tighten the rear sub frame to front chassis rail retaining bolts to.
Tighten
Tighten the bolts to 240 N·m (178 lb ft).
17. Remove the two (M10 x 1.5) 115 mm special tool kit EN-48536 transmission support to body
retaining bolts (1).
18. Install the four original transmission support to lower sub frame retaining bolts (1).
Tighten
Tighten the bolts to 55 N·m (41 lb ft).
19. Remove the support from under the power train.
Important: Right hand drive shown, left hand drive similar.
Important: The intermediate steering shaft and pinion shaft splines must be installed in the
position recorded during removal and aligned with the marks previously made.
20. Connect the intermediate steering shaft (1) to the pinion shaft (3).
21. Install a NEW intermediate steering shaft to pinion shaft retaining bolt (2).
Tighten
Tighten the bolts to 25 N·m (18 lb ft).
22. Install the radiator support bracket (2) to the radiator slide pin assembly (1) on both sides.
23. Push the securing lock (3) into the radiator support bracket (2) making sure it is correctly seated on
both sides.
24. Install the propeller shaft. Refer to Propeller Shaft Replacement.
25. Install the exhaust system. Refer to Exhaust System Replacement.
26. Install the engine coolant inlet pipe. Refer to Engine Coolant Inlet Pipe Replacement.
27. Install the engine splash shield if equipped. Refer to Engine Splash Shield Replacement.
28. Install the front air deflector. Refer to Front Air Deflector Replacement.
29. Remove the material used to cover the exposed cylinder head inlet ports.
30. Lower the vehicle.
31. Install the lower intake manifold. Refer to Lower Intake Manifold Replacement.
32. Install the air cleaner inlet duct. Refer to Air Cleaner Inlet Duct Replacement.
33. Install the engine cover. Refer to Engine Cover Replacement.
34. Install the air inlet grille panel. Refer to Air Inlet Grille Panel Replacement.
35. Connect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection.
36. Fill the cooling system. Refer to Cooling System Draining and Filling.
37. Inspect the cooling system for coolant leaks and repair as necessary.

[azazeldeath]

I havent had a chance to do it yet, I have a feeling it may not be the Thermostat, or not completely. I noticed the second I turn the aircon the fans kick in and the temp drops back to normal. But I will still do it soon I recon. Thanks.

[khanz]

hey if you haven't done it yet all you have to do is drain, remove inlet manifold and one of the hose from the heater tap.
you can then squeeze your hands down the back to reach to the bolts.
there's 3 10mm bolts holding the thermostat housing, but to get to 2 of them you have to remove the pipe that goes to your heater tap.
the pipe for that goes to the heater is held in by 2 10mm's and a 15mm(if I'm not mistaken).
Another way is to drop your exhaust and then you can get your hands in there. from pass experience on the alloytec change your radiator cap, they fail and water goes to your overflow and cause over heating

[RiCeY]

Whats the issue, very unlikely that its the thermostat as Ive been with Holden for years and never changed a single one.

[km5]

air in your cooling system?

[CRUSTIN]

Can you notice your fans kicking In when your sitting and its heating up? And if its your fans that are the problem, it won't overheat at speed. Whereas the thermostat will make it overheat at any time.