what can cause a cosworth to smoke?
with mine when i'm slowing down with using my engine there's no smoke but as soon as i press the throttle a there's a puff of smoke?

i know it points to the turbo but could there be any other reason say if the turbo was brand new?

 

the smoke is blue so must be oil.

 

it could be the valve sills letting pass, but a lot of cossies do smoke a little for some reason

 

would'nt that be smokey on start up.

there's no smoke on start up or even when you rev up when stud still.

 

other than the oil rings which again would be smoke on start up i would have to say turbo, are the turbo sills ok

 

Valve stem seals can be on the way out and it not smoke on startup.

Have they been done?

 

it needs a rebuild mate..that sounds like blow by(oil passing the rings)..
Might get away with a hone and re ring but more likely a rebore and new pistons..
Best thing to do is monitor your oil ussage,around a ltr per 1000 miles if your booting it about any more and youve got issues....
Any one saying this is normal is putting their head in the sand!!!also if it was fuel smoke it would be dark grey/black and means you need a better map..


cheers danny

 

would that not smoke all the time if it was the rings?

 

as BLACKCOSSIESTU said not normaly stems seal's them selves that cause this...normaly shot valve guides (which in turn knacker the stem seals....new seals will probably mask the fault on a car thats not used much and will also probably last quite a while tbh) or oil control rings.

dooge

 

id be here all night explaining it mate but believe me iv had so many cossies and rebuilt so many engines that if its not the turbo it will be the bottom end..
If it was valve stem it would smoke on start up etc and would be different to when backing of the throttle and suckin up the oil past the rings,when you go back on the throttle it will blow a puff clear then come back on when you throttle of then the whole process will repeat itself...not a good explanation but thats the best i can explain it...


cheers danny

 

a good test is to find a big hill; let the engine overrun down the hill, then at the bottom give it a boot - if you get blue smoke its normally a good indication to stem seals or guides

but as Danny said it could also be oil rings; but start with the cheapest first!

if it is oil rings; it wont always show on a pressure test

 

Not all cossies smoke, well mine dont, as said it could well be stem seals or rings.

Steve