'98 V70 T5, Auto, 154,000 miles. Changed oil and noticed smell of burning oil thereafter. Checked the drain plug and filter, both tight and leak free. Car has typically not been a big leaker for the last 100,000 miles I have owned it, a small drip here and there. Nothing like the amount of oil coming out of it now.

Just got back from my mechanic, who put car on the rack, noted oil coming from drain hole at bottom of tranny/motor connection, he thought it might be rear main seal. Also oil on bottom of engine on drivers side. Could find no oil leaking from top of engine down, slight weep from valve cover gasket. No obvious sign of source of the oil leak. The oil return line on the turbo was not leaking. Slight leak noted at oil cooler hose under radiator. Mechanic pressure washed the motor top and bottom to clean all the old oil and we ran engine for twenty minutes at idle and then put it back on the rack. No oil appeared to be dripping from anywhere. He thought, "maybe its fixed?". I drove the car home and quickly noticed burnt oil smell again.

Did a search here and noted other posts suggesting pcv might need attention. I have never serviced the crankcase vent system. Is there any documentation or infomation available on how to do this. Is it more likely than not that this is a rear main seal leak or is there any hope that this is something less catastrophic like the car needed to have the crankcase vent system cleaned?

Thanks.