White smoke during hard acceleration

[jptravers]

Having this same problem myself -- massive oil deposit on undercarriage, burning smell and smoke at high RPM, first noticed during high acceleration (aggressive driving). Got under the car to investigate source, couldn't find it. This looks like a promising lead for my 2002 V70, ESPECIALLY since on a recent service write-up, the Volvo tech listed "engine block plug for non-turbo return port" as a recommended service, with cost of $255.