If you find that your car’s oil needs topping off between oil changes, then it is probably leaking oil – and you may not have noticed it. Some cars leak oil only while driving and the engine is hot. These types of leaks can be difficult to detect and you may need to have the engine seals and gaskets inspected at an auto repair shop.
But, if you have a problem with your car leaking oil when it’s parked, here are some reasons why that may be happening.
Why Oil is Leak Right After Parking Car
Bad Seals or Gasket
Immediately after driving, a car’s engine block and head are hot. Hot metal components expand, putting pressure on the engine’s seals and gaskets which is meant to prevent oil leakage. But, as the engine cools down, those metals will contract and leave gaps between the rubber seals and metal components. An auto repair shop can determine if it is a bad oil gasket or pan, a leaking main seal, or a bad ring or valve seal that is worn and has open gaps which allow oil to leak after parking the car.
Damaged Oil Filter or Oil Pan
A bad oil filter can that was not caught by the manufacturer can cause the oil to leak as it is passing through the filter and into the car’s engine. Also, a damaged oil pan can leave puddles of oil underneath the car after driving. When driving over low-lying portions of the road, an oil pan can be dented or hit with enough force to cause damage. The result can be a fast leak when the car is parked or a slow drip the gets worse over time.
Oil Pan Plug is not in Place
Your oil pan plug may have stripped threads or it may not be inserted and tightened properly. A rubber plug can serve as a temporary replacement but eventually a permanent repair may involve replacing the oil pan plug with a hardened steel thread insert that is the right size and thread pitch for your car’s oil pan.
A Blown Head Gasket or Engine Block Seals
If you drive an older car, the problem could be a blown head gasket or the rubber materials that seal your engine block may have deteriorated and is causing oil to leak from the top of the engine block. Driving a car without enough coolant can create an overheated engine which may cause the cylinder head to warp and a head gasket to leak. For those that live in a colder climate an engine block can freeze when there is not enough antifreeze to keep the system water from freezing. If either of these have happened, you may need an engine overhaul or an engine replacement.
Contact your local auto repair shop if your car is leaking oil after parking. It may be as simple as parking on a hill, or as complex as a crack in the engine’s sealing materials. Leaking engine oil will be light brown or black and will have a distinctive oily smell as opposed to a burnt smell which is associated with brake fluid or power steering fluid.