Midas Cars Forum - www.midascarsforum.com

While investigating the reason for a slightly high tickover, I realised I don't really understand how the Metro air inlet works. There's a hose from the manifold going to that plastic widget with 'AC' on it, then to a vacuum cylinder connected to the flap.Doesn't the temperature control it in some way? The hose on the manifold had perished so it probably hasn't worked properly for ages. Disappointingly that isn't the cause of the fast tickover.

Its a wax thermostat, as the hot air enters the intake and it reaches optimal temps for warm up the thermostat opens allowing vaccum to flow through and open the flap closing off the warm air feed from the exhaust and opening up the cold air feed.

In a roundabout kind of way

The default position of the flap is closed to hot air/open to cold. So the flap will open to hot air when the engine starts?

That'll be it mate, my 205 was the same

Now all I need is some 3/16" bore hose, which isn't the same as 5mm as some people think...

I find eBay good for that, mind you how much do you need I've got various bits kicking about

Geoff Butcher wrote:Now all I need is some 3/16" bore hose, which isn't the same as 5mm as some people think...

It may be difficult to obtain exactly 3/16" hose, now being in our metric way of life, imperial sizes are now rounded to the metric equivalent which isn't always suitable.

I need 1 or 2 bits about 45 cm each

Could you get 4mm and stretch it on?

Geoff Butcher wrote:I need 1 or 2 bits about 45 cm each

I'll take a look