Hot air intake

Discussion in 'Mech Tech' started by Markpc, Aug 12, 2016.

  1. The temp valve that opens and closes the hot air intake flap vacuum can thingy is broken.

    Does anybody know at what temperature it gets hot air?

    It's failed in the 'cold air position' so I've blocked off the vacuum feed to it, but I noticed a bit of carb icing on the right hand carb manifold, and slight hesitation. Am I ok to temporarily force it into the 'hot' position? Or will this cause over heating issues?

    Oh its a 2ltr T4.
  2. Generally, once engines are warmed up, they don't like breathing hot air - performance may go down.
  3. Its probably OK because the manifold vacuum that feeds the air flap via the switch goes away at wider throttle opening, so the flap will flop to the 'cold' position by itself, as it does even when the little switch is working, to avoid breathing too-hot air in conditions when the throttle is wide open.

    The temperature it clicks over is meant to be 30 degrees C. I believe the same part is used on everything from the oil bath cleaners on T1 up to early Golfs so you should be able to get one hidden in an air cleaner for a lot less than the £60 they cost as a spare.

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