Hi, my 1.6 felly has a smoking issue, but not like anything I've experienced before.

It drives great, pulls really well, with no rattles etc, (although slight misfire / flat spot about 3k sometimes) if you floor the throttle and generally drive briskly everywhere then there is no blue haze or smoke, but if you happen to drive off the throttle such as coasting down a hill then there is a huge plume of blue smoke when you gently touch the throttle to start accelerating again.

During the day it starts up cleanly, but if the car has been standing over night there is a puff of blue smoke when it first starts.

My personal opinion is oil getting passed the valve stem oil seals but what does everyone else think?

The car has done 99K miles, doesn't blow smoke out of the oil filler cap area or out of the dip stick with them removed.

It's previous life 300 miles ago was as a takeaway delivery car doing lots of stop start motoring and when I got it 300 miles ago it had the most carboned up plugs I'd ever seen - you could not tell what part was tip and what part was electrode! it was just a solid lump of carbon. (these have of course been changed).

There was a split breather pipe, but I've changed this, but not done anything about the canister thingy at the back of the block which it goes into.

try changing the oil seperator unit on the back on the engine block

Hi tom, thanks for that info...what exactly does an oil separator unit look like? (and for that matter what does it do?).

Is it the bit that the breather pipe ultimately goes to?

thanks again

Tom knows more about the Felly specifics than I do, but this would make me think of worn rings or valve stem oil seals. I guess you know that a compression test would sort out which of the 2 it was, if it was either.

Thanks for the pic, yes thats the thing at the end of the breather pipe, if I understand it correctly the crankcase vents into it, the heavy oil sits at the bottom and returns to the engine and the oil fumes / crankcase fumes are sent skyward and into the air intake.

Well, all exits and entries to my oil separator are heavily gunked up so fingers crossed a good soak in some degreasant will really help; if not I'll be out with the compression guage, although if it was piston rings I'd expect greater smoke under heavy throttle wouldn't I?

I won't be able to drive it until tommorow now to test it but I'll let you know.

thanks.

As expected I haven't been able to take it for a test drive yet, but I can confirm that cleaning the oil separator has made a dramatic change to the car.Previously when cold the tickover was lumpy and at about 500 rpm, and occasionally stalling until it had been running for a minute or two, now the car started and was "idling" at 1400 rpm!Lets see what happens when I go for a test drive.

if it's idling at about 1400rpm you might have a vacuum leak somewhere,

That or the throttle's sticking part-open. That's dead easy to check; just make sure there's a little free play in the cable with the engine off.

well Ken you win the prize...I'd caught the throttle cable when refitting the oil separator and altered my idle that way.

Anyway, I've now had time for a road test, I previously removed the oil separator, soaked it in degreasant and refitted it once it was like new. It cured the erratic idle immeidiately and it has certainly made a huge difference to the flow of gases through the breather system.

I think that there is a degree of wear and tear to the engine, but it now runs as clean as a whistle 99.9% of the time. ..I now think that what was previously smoke carrying a lot of oil has now cleaned up and is actually possibly overfuelling - which was being masked by a blue tinge from crankcase pressure building due to the blocked breather.

There is still an exceptional cloud of smoke when you initially return to the throttle after coming down a hill totally off the throttle but at high revs due to engine braking, but perhaps this is over fuelling when in this state of high revs zero throttle? so a compression test I think, to rule out rings, then perhaps a cheap lambda sensor for overfuelling (I know they don't last as long, but they also don't cost as much), and then it's got to be valve stem seals?thanks for everyones advice so far, it is apprieciated.

How much oil is the engine using between services?

How much oil is the engine using between services?

I've only had the car for about 300 miles so I'm not quite sure, but even if I knew the quantity would that actually help me determine the fault?

Matt, what colour is the smoke now?

sorry for the delay, I wanted to get some more miles under it's belt. I can now confirm that there is a distinct improvment since cleaning out the oil separator.Any smoke is a less thick but does still have a blue tinge. I am now 99.9 % certain that it's valve stem seals as it ONLY happens on the overrun (i.e. after coming down a hill on zero throttle).is it a big job to change them on the 1.6 engine?

That could still be seals or rings, but as long as it's only on big changes in manifold depression, it's not urgent.

I think seals are more likely though, based on your OP saying the crankcase isn't pressurising.

Agree with Ken that it can't be particularly urgent. Especially if oil consumption is acceptable.

Valve stem seals were a weak point with earlier VAG engines which I guess was the reason that the owner's manual of our old Audi 1985 (1.8 litres) stated that oil consumption up to 1 litre per 1000 miles could be considered normal. The Felly 1.6 (AEE) engine isn't that bad, of course.