Originally Posted by borgiewindsor
ok , pinging under load , a hassle when cold , backfire though carbie ( sometimes when rev) and a whiteish sorta smoke when engine is revved , but no smoke when idle , what the hell is it , its only juat started to do it , i though carbie but have two carbies and same with both , and one is new , so am very doubtful its carbie , could timin have jumped a tooth ,
Apart from a broken or wicking head gasket or intake gasket, the white smoke could be a leaking exhaust valve stem seal. You can usually tell the difference between water/glycol vapour as it disperses fairly rapidly, while oil vapour will billow out and travel across the neighbourhood.
The backfire can be caused by poor valve timing, leaking intake gasket, open ended vacuum hosing, bad PCV. A glowing exhaust valve/sparkplug will also produce a backfire as well as pinking.
Try a compression test first. A vacuum gauge will tell you if you have an exhaust valve chucking a wobbly.