Series 3 Suck or blow?

I had some idle problems on my s3 petrol recently after a brisk 200 miles on the motorway. I've just cleaned the idle jets and that seems to have more or less sorted it but I noticed something else.

The engine breather used to very gently blow (if you put a thumb over the outlet on the Dalek head it would give a slight puff after holding it a few seconds). Now it constantly sucks, not hard, but noticeably with a constant sucking noise.

Any ideas what the cause is likely to be? Piston rights, valves?

I won't have time to strip it down for a while so hopefully it wont do any immense harm...

D

Im sure thats a Hebden Bridge thing. I hear half the women there cant make their minds up these days.

blow is just a figure of speech!

Constant sucking? Interesting.i would guess valve guide specifically inlets. Piston or rings should cause pressure.
But there should some other symptom like smoke or compression loss. So I don't really know (he says helpfully)

Pure guesswork but if you've not got a hardened head could the 200 miles at motorway speeds have caused damage to the valve seats 'lead memory'? May cause issues?

I doubt if 200 miles will cause valve seat recession. My P4 Rover has never had the head off in the last 40 years.

Thanks lads, it has got hardened valves and seats so it shouldn't be that. I think I'll whip the rocker box off and see if I can see where it's sucking from. The tappets all sound ok and it's not running lumpy. All I can think of is a piston ring but then I'd expect it to be blowing...

If its got the crankcase breather routed into the inlet tract could that be causing your suck?

Yep a suck or blow depends which end you have your thumb over.

Worn inlet valve guide/s?
Inlet side is the only bit that is under a vacuum.

Sorry lads, turns out I am an idiot .... I'd still got the PCV pipe to the carb attached - what a knob! Still having idle issues so looks like a full carb strip down / new manifold gaskets are in order.