Forgive me if this has already been covered but what position should the adjustable pipe that comes off the air filter pan be in and what's its purpose?...

Any particular car?

Hi Justin.
There is an arrow on the pan and one on the removable pipe. Line them up.
Pipe will be facing downwards towards the front of the rad.
Cheers Mark.

I think this is a summer /winter issue. From memory (haven't looked at the 1.4 lately) the pipe can be pointed to pick up some hot air from the engine / radiator (just can't remember the details) in winter and towards a circular hole in the front panel to pick up cold air in hot weather. It never seems to make much difference

Ah this is the early preheater. Its to prevent carb icing, you won't see it in normal town driving. I ran my car without the pipe for while. Problems started to happen after about 20 mins on the motorway in near freezing temps. The car starts to loose power and doesn't run well due to ice or water building up on the carb jets.

Thanks, I forgot to say my cars a Volvo 340DL 1.4 1988. What is the actual position of the pipe for;

A: Summer Use?

B: Winter use?

According to my Haynes manual, the flap switch should be down for summer and up for winter. The should be a 'W' and 'S' on the end of the filter body. From 79 a thermostat controls it automatically.

Hello again. Flap switch?? I'm not sure there is one on the late models e.g. 1988 cars. You are right, there is some sort of thermostatic type of device in the pipe that carries air into the filter pan so that it can either draw cold air from the front of the car or hot air through a flexible ali pipe from the exhaust manifold. In addition to this, the late models have an extra level of sophistication in that you can tilt the cold air inlet pipe, either towards the front of the car for very cold air or towards the radiator for air that is a bit warmer..... but, as myself and others have said, it never seems to make any difference and the pipe has a mind of its own as it rattles about and usually ends up pointing forwards wherever you set it to..... but as a safe bet, I would simply twist the pipe so that points towards the rad for now and not worry about it further.