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V6 VX Thermostat replacement

Discussion in 'VT - VX Holden Commodore (1997 - 2002)' started by leonz1982, Jun 16, 2012.

  1. leonz1982

    leonz1982 New Member

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    Hi guys,

    Going to properly flush the cooling system on my VX so went to local Holden spare to buy a genuine thermostat for $11. When they ask me if I needed the gasket and O ring, I was a little unsure. I know you will need to replace the gasket when removing the housing but I didn't know it has a O ring? It turn out they don't have the gasket and O ring in stock so I had to go supercheap. Supercheap Auto's only had the gasket but when I asked the employee there about the O ring, they said the VX shouldn't have an O ring, just need a gasket. So I just bought a Tridon self adhesive gasket for $3.

    Anyone know if there is an O ring in the housing and does it need to be replaced if opened?

    Share some light please guys. Thanks.
     
  2. Biglachs

    Biglachs New Member

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    Gday leon.

    There is an O ring but its located just below the housing on the inlet manifold. You will see a pipe looking thing in a little gap if you look down the left hand side. That connects to the heater tap hoses. On the end of the pipe is the O ring. If it isn't leaking, I wouldn't bother replacing it.

    [​IMG]

    -lachy
     
  3. Promotec

    Promotec New Member

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    I have always just used the gasket, on one surface there is a groove for an O-ring but Ive never used it, over the years I have changed the thermostat many times all with just gasket, avoid supercheap thermostats
    I have had two in a row seize after about 6 months use, supercheap and super nasty.
     
  4. kyalkk

    kyalkk Donating Member

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    get a 81 degree thermostat, little dearer but they make it run better, can get them from mace i think
     
  5. vxcommodore80

    vxcommodore80 Banned

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    would agree with the mace 81degree :D
     
  6. Pollushon

    Pollushon Boost gives me a bar....

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    As above only the gasket is required for the thermostat to be replaced. It's a great time to flush as you can get a great flow of high pressure water through.

    The old 81 degree chestnut. There's absolutely no empirical data to support the 81 degree thermostat providing any sort of gain. As much as I love Mace the OP should be aware of this, these engines were manufactured for 8 years at 92 degree and 20 psi, which only rivals a bimmer m60 setup. Overcooling an Eco is bad, cept you don't really know when you are. If your engine runs 'better' by cooling it beyond factory specs you're only ignoring a root cause somewhere else.
     
  7. commodore665

    commodore665 expat Saffa

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    Why is it bad to over cool Eco Tec 's
     
  8. spauldj308

    spauldj308 S Pack Man

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    Oil may not get to proper operating temperature, can may run rich because the ECU may think it is in cold start all the time.
     
  9. Pollushon

    Pollushon Boost gives me a bar....

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    Emo's are cast and metal expands with heat, more so when it's cast as opposed alloy composite. The engine component tolerances are built with this in mind and operating temp is the sweet spot. Run it too cool and your not running at tolerance. On top of this the Emo is a high pressure system (20 psi) so it's designed to run quite hot compared to most, short of the M60 which can do up to 2 bar or 113 degrees, but contrary to belief this isn't bad.

    To clarify the 81 degree won't necessary make the motor run too cool, but it can spend more time in the 'danger' zone. I'd never use one here in Canberra, especially during winter and spring.

    I'd be happy to eat my words if there was some sort of data on the matter.
     
  10. BlackVXGTS

    BlackVXGTS Well-Known Member

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    Some food for thought:

    "Thermal Efficiency
    Before we go into what a cooling system does and how to modify it, you must first understand what the engine does. Plain and simple, an engine makes heat energy and turns it into mechanical energy. Any heat generated that does not get used to make power is wasted energy. How well an engine converts the heat it generates into mechanical energy is known as it's thermal efficiency.
    The cooling system takes heat from the engine, heat that ideally could have made power, so the cooling system actually takes power from the engine. It is a necessary evil, without a cooling system, the engine will overheat and the internal parts will have a very short life.
    A cooling system will also reduce the chances of detonation. With new cooling systems and coolants, it is possible to run today's engines hotter, which increases thermal efficiency. If you take less heat away from the engine, there will be more energy available to make power.
    Any heat that is radiated off the engine, and out the exhaust system is also wasted heat energy that did not get used to make power, which reduces thermal efficiency. The average engine has only a 25-30% thermal efficiency, so 70-75% of the heat generated never gets used to make power. An average 250hp gasoline engine is actually burning enough fuel to make about 1000 hp, making it a very inefficient machine."
     

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