I never had any oil leaks in that area.
Most common oil leaks are from:
1. upper and lower balance shaft seals
2. front crank seal
3. front camshaft seal
4. rear main seal.
5. oil pan seal
6. valve cover gasket
If it is engine oil, it could be the valve cover gasket.
It will leak on the exhaust side because engine is inclined towards the exhaust side.
Are you sure it is not ATF from power steering hose? That's also a common leak.
Also, have you checked the camshaft chain tensioner pad?
If that pad disintegrates, it will destroy the cam chain and sprockets. Look at the pic in red circle.
