I have recently replaced my old worn out Zetec with a supposedly good 60,000 mile one.The problem is this one blows big clouds of smoke when first started from cold and also when hot if revved hard, but seems ok when driving gently.I did about a 100miles in it at the weekend and used enough oil to go from the high to the low mark on the dipstick.It does go ok and has no tappet noise like the old one did, apart from when i first drove it when it occasionally went onto 3 cylinders on light load.I removed the plugs today before starting it and found numbers 1 2 and 4 were a light grey coulor but 3 was sooty and when i looked in the bore with a torch there was wet oil on the piston crown.This would explain the smoking from cold start if the valve guide seals are allowing in oil but I dont think guide seals would cause it to smoke when under load.
Has anyone had similiar problems ? would it be worth filling the bores with redex and leaving to soak for a few days in case it is sticking rings? .I dont think it will be worn bores as the engine was immaculate inside with no sludge and doesnt seem to breath from the crank breather like the old one did and theres no oil in the catch tank, I cant do a compression test at the moment as my tester wont fit the zetec head.
Paul

[Edited on 9/6/08 by paulf]

Hi Paul,
When I followed you yesterday at Pitsford it fired a big plume of grey smoke out when you first put you foot down. This cleared and then another as your floored it in 2nd. That cleared and then another as you floored it in third.

It wasn't doing it under normal driving, just big puffs on initial high load in each gear.

Jan breathed most of it in so you didn't do too much damage to the environment.

By the way did you notice me NOT disappearing out of you rear view mirror.

David

Seems fairly likely to be a valve guide seal...every time you back off to change gears, there's a lot of vacuum in the cylinders - enough to pull oil by a bad guide seal. My 944 does this, too, though only when cold.

Still having problems with this, I put a mixture of redex and injector cleaner in each bore and made an improvement to it, but it still burns oil at high revs.I did a 60 mile return jorney yesterday and when i got home took the plugs out with the engine hot and found the top of number 3 piston was wet with oil again.
I have just looked at the engine i removed and noticed that the oilway from block to head is next to number 3 cylinder, I am now wondering if it could be leaking oil via the head gasket into the bore although I have no other head gasket symptoms.
Paul.