Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Please note that it is not permitted to have referral links posted in your signature. Keep these links contained in the appropriate forum. Thank you.

https://www.boards.ie/discussion/2055940817/signature-rules
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

What a failed BMW thermostat looks like

  • 13-09-2010 6:46pm
    #1
    Voodoomelon
    Registered Users, Registered Users 2 Posts: 9,661 ✭✭✭


    stat.jpg

    The above is from a 2000 BMW 728i E38 with an M52 straight six.

    The symptoms were that whenever the car was on the motorway or any main road doing more than about 80kph, the engine temperature would drop down towards the blue. It would then warm up again as soon as I was back in town in slower moving traffic.

    As you can see the two arms that hold the thermostat in place under tension have snapped, leaving the stat in an open position the whole time. This resulted in coolant being passed to the radiator non stop, regardless of engine temperature.

    I was only going to buy the thermostat from the dealer before I knew that the exact problem was, but I sprung for the stat/housing assembly in case and good job I did.

    It took me about 2 hours to get it in having never done the job before, its a pain in the arse as the whole fan clutch/shroud has to come out to get access to the front of the engine, which also means all the lower coolant houses and auxilary water pump have to be disconnected from the lower part of the shroud.

    I took it out on the motorway this evening and the temperature needle didn't budge a millimeter at full pelt, she also comes up to temperature a lot quicker than it was.

    Anyways, job done, thought i'd share. :)

    DSCF9700.jpg

    Oh, and price was about €80 for the stat and housing.


Comments

  • #2
    Slidey
    Closed Accounts Posts: 12,811 ✭✭✭✭Slidey


    Good job lad


  • #3
    daveharnett
    Registered Users, Registered Users 2 Posts: 2,567 ✭✭✭daveharnett


    Voodoomelon wrote: »
    its a pain in the arse as the whole fan clutch/shroud has to come out to get access to the front of the engine, which also means all the lower coolant houses and auxilary water pump have to be disconnected from the lower part of the shroud
    Still, could be worse. Isn't it more common for them to stick closed and explode?


  • #4
    Voodoomelon
    Registered Users, Registered Users 2 Posts: 9,661 ✭✭✭Voodoomelon


    Not on this engine, they're designed to fail open. Why they used plastic for those arms is beyond me, the spring pressure is immense.


  • #5
    mondeo
    Registered Users, Registered Users 2 Posts: 3,680 ✭✭✭mondeo


    Voodoomelon wrote: »
    Not on this engine, they're designed to fail open. Why they used plastic for those arms is beyond me, the spring pressure is immense.

    I never heard of one failing in the closed position. I did the same job on my friends 320 a few weeks back.


  • #6
    Plug
    Registered Users, Registered Users 2 Posts: 9,248 ✭✭✭Plug


    mondeo wrote: »
    I never heard of one failing in the closed position. I did the same job on my friends 320 a few weeks back.
    I've seen ones where the wax comes out the thermostat and it remains in the closed position.


  • Advertisement
Advertisement