Hi all,

Just had the 2CV MOTd on wednesday and an oil and filter change. Only driven it twice since then, but it's now making a puff of smoke on start-up (and smelling smoky, not exhausty) and the oil pressure light no longer lights - well it flickers on cranking and that's all.

Any ideas? Are the issues related?

I assume you did not do the change - check the level (obvious sorry) check the pipe from the filler to the airbox, the connection to the sensor, check the oil filter's tight and no oil leaking on to the exhaust box. Have a good look around and have someone start with you under the bonnet etc....

Whilst checking the connection at the oil pressure sender, there's also a bullet connection on the light bar that is the circuit to the sender.I found out when I thought the sender had failed

No I didn't do the change - the level is bang on full and the filter tight. All pipes are tight and jubilee clipped. There's no loose oil anywhere, the engine is nice and clean and shiny.

I've just had a play after lunch and can't see anything obviously amiss, it starts ok (first turn of the starter) but the light only flashes when the engine turns, not with the ignition. Plugs are nice and clean.

do you park on a camber?
can you get it to smoke by lifting off then hitting the accelerator again does it smoke under load?
was there any oil in it before?

sounds like the sender is on its way out and probably un related to the smoke issue which may just be oil leaking past the rings after its switched off - and worse if its tipped over.

In both cases it was parked nose down amd slightly to the right - the last few months it's usually been perfectly flat (it's now been ousted from the barn to the outside for the summer while the x1/9 takes up residence). It doesn't smoke when running at all, just the puff on starting. Just started it again and no smoke this time.

There was oil in it before - near the bottom of the acceptable max/min.
Connections to the sender seem ok, so will get a new one put in and see what happens.

Richard

PS would a CPD valve help at all? Although saying that ecas website says no stock.

I would do a test first with pipe/water etc to check if you need one....

a good CPD is always a benifit but not really the cause of the fault here. When the engine is switched off the oil oin the bores below the rings normally drains out into the block , but if its on a slope the oil pools in the bore added to this the rings wander round in their grooves and occasionally the gaps all line up at the bottom and cause smoky starts usually goes away after a bit.

main tjing if it runs ok id not worry about it

As Sean has pointed out this is something that will happen with flat engines.I had boxer BMW bikes for over twenty years and they would always smoke on start up if left on the side stand,my later K series was even worse, although not a boxer the 4 cylinders lie on the side across the frame and it wasn't a puff of smoke on start up.there was a smoke screen I put over 100,000 miles on a boxer and a K without any problems so now't to worry about in my book

Must admit most of my numerous A series gave a little puff of smoke on start up and non ran out of oil so I don't think that is really a major issue - more of an issue I guess if you have large amounts of smoke on the over run and then going back on the power.....