I need to know if a garage who over filled my 540 with at least 9 ltrs of oil ,maybe more if they never removed the oil filter housing cover when draining oil may be legally liable for damages so I may seek recovery of the expenses of repairing ... got low coolant and billowing white smoke as the engine warms up the day after I had my car oil changed... I supplied two 5 litre bottles of LubraMoly 5w40 and they added nine litres.. I had them drain out some but they still left me with too much.. The shop was closing as it was in the evening so i drove off but can too much oil create conditions that can damage the head gasket? More importantly if yes ,how does this occur.. I may need to bring some explanation of the engine design and physics to support a claim for reimbursement.