1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  2. Dismiss Notice

Thermostat faulty?

ab1702 Sep 2, 2020

  1. ab1702

    ab1702 Registered User

    846
    259
    63
    Just wondering if it causes any issues running the car with a faulty thermostat that seems to open too early or is stuck open?

    My temp gauge has been dodgy for quite a while now. It doesn’t get upto 90 and stay there ever, if it does get upto 90 then it will drop back down at some point sometimes going as low as 70. If I have the heater fans on inside the car then it rarely gets above 70.

    I took the car for service and mot last week and asked the guy to change the thermostat aswell. He rang me a bit later saying it’s a nightmare job on my car and he’d want it back another day for most of the day if I want it doing as he reckons he’d have to take most of the front end off to get to it. However in his opinion if the car isn’t overheating then he said he’d just leave it.
    Like I said above if I just leave it is there any problems this could lead to as most of the time the car will be running cooler than what it should be?
    The car is a 2009 sportback Quattro 170 TDI CBBB engine.

    thanks
     
  2. Avatar

    snack-media
    Advertisement


  3. samisnake

    samisnake Registered User

    766
    320
    63
    its 'better' having it stuck open than stuck closed, thats true.
    your engine will not be running at optimal temperature, so increased wear and reduced fuel consumption are the main issues.
    i wouldnt just leave it.

    attached is the elsawin guide on replacing it on a cbbb engine. doesnt look like a nightmare job, take it elsewhere
     

    Attached Files:

  4. Matt268uk

    Matt268uk A3 Sportback VCDS Map User

    935
    194
    43
    It's not a nightmare job and actually pretty straight forward it your handy with tools. As Sam has shown above, just follow that and you'll be all good.
     
  5. ab1702

    ab1702 Registered User

    846
    259
    63
    I appreciate your help and the guide, however that doesn’t look like my thermostat unless I’m looking at it wrong.
    On mine I think the thermostat housing has 3 hoses/pipes coming off it and a quick search on eBay for a replacement shows the same thing aswell. The engine is definitely 100% CBBB aswell.
     
  6. samisnake

    samisnake Registered User

    766
    320
    63

    just looked again to make sure, and it turns out there is two styles of thermostat on the cbbb.
    the one i linked to above, or a different style housed inside a 4/2 way valve like what you saw on ebay.

    attached the exploded view and the guide for the 4/2 way valve.
    if yours is like the 4/2 way valve one, then you gotta remove the alternator, but a nightmare i still dont think it is tbh.
    compare the pics to your car
     

    Attached Files:

  7. ab1702

    ab1702 Registered User

    846
    259
    63
    Yes I’ve just found that guide aswell, I’ve just stumbled across what looks like a full free pdf guide of elsawin Online so ive downloaded that.
    From what I can see you have to remove the throttle valve module, remove alternator, remove air con compressor, remove the air pipe connected to the intake manifold flap motor and also move the fuel filter out of the way.
     

Share This Page

Do Not Sell My Personal Information