Can anybody offer help? My cheaply purchased Zafira A 1.6 16v petrol has been pumping out a lot of smoke (clouds!), feeling "strangled" and underpowered, and knocking under load. It burns a lot of oil, I top it up about twice a week and the knocking stops immediately afterwards, but returns in a day or two (low mileage, local town driving mainly, although it has had a few 200+mile Mway trips recently. Since buying it have cleaned breathers (2 small, 1 large to sump) which weren't completely blocked but had tons of mayo inside. Replaced EGR (as prior to this engine kept cutting out, old EGR was coked up). Cleaned throttle body. Nothing made any difference to smoke/strangled power/knocking. On basis it may have been a blocked oilway/pickup filter I removed cam cover and sump. Cam cover wasn;t too bad, internal breather pipe was clear. Sump very black but filter not blocked. Cleaned everything up anyway. While apart I poked around the oilways without really knowing what I was doing (honesty is prob the best policy here!). I also turned the engine by rotating a camshaft while it was apart (didn't remove timing chain). Battery was disconnected the entire time.
So - it all went back together without a problem. Turned ignition, engine cranks fine, catches, then almost immediately cuts out. Same thing everytime. No errors when doing pedal test at this point. Eventually I disconnected the crank sensor, it then fires and idles fast/not smoothly, rev it and it knocks. Reconnect the crank sensor and back to firing/cutting out straightway. Now have a 0335 error code (which makes sense I suppose having run it withoug crank sensor connected). I've now broken the "lock" on the sensor connector so it doesn't stay in tightly, but as that was after these problems I don't think that's relevant. Replaced crank sensor but no change at all.
Any ideas? Could I have somehow messed up the timing by turning it over by hand? Could I have damaged something poking around the oilways?
Thanks, sorry it's so long-winded!
Jamie