Car leaking oil under the car is one of the most frequently asked questions I usually get. Many people think that their car is leaking oil if they see drops on the floor when they park in front of their house or in a parking lot etc.
7 Reasons why is car leaking oil from under the car
So here are some reasons why your car might be leaking oil under the engine:
Overfilling or over-pressurizing
If you overfill your engine’s oil, it can overflow through gaskets and seals beneath your vehicle. If you don’t check air pressure regularly, low tire pressure can also lead to leaks from these places.
A good way to check for leaks is to monitor the level of fluid in your windshield wiper reservoir at regular intervals – this will give you an indication as to whether any fluids are leaking from your car and where they’re coming from. If the level of windshield washer fluid is dropping, then you probably have a leak somewhere on your car – if it’s not dropping, then you’ve found the problem!
Oil pan gasket
The oil pan sits at the bottom of the engine and channels all used engine oil back into the oil pump for re-circulation. It can develop leaks as a result of corrosion or mechanical damage (e.g. after an accident) and may need to be replaced by a qualified auto mechanic; however, sometimes these leaks can be temporarily patched up using special silicone sealant available at most automotive stores.
A damaged valve cover gasket or a crack in a valve cover
The valve cover sits over the engine’s internal parts and keeps these clean and free from contaminants – if it develops a leak, oil will seep out near this area. If you notice that your car is leaking oil from under the hood, then it may be due to a damaged or cracked valve cover gasket. These can usually be repaired by qualified mechanics but sometimes they need to be replaced because of excessive damage – especially if pieces have been torn off which can block an air filter etc.
Cylinder head or valve damage
If your car is leaking oil from under the hood, then you might have damaged cylinders or valves that require repair or replacement. Engine block damage can also lead to leaks through this area; however, these will usually require an engine rebuild and the work of a professional mechanic who knows how to handle high-performance engines (e.g. race cars).
Oil residue on spark plugs
You might want to check your car’s spark plugs for oil residue if it’s leaking oil from under the hood. Oil residue on spark plugs is often one of the first signs that your engine may be leaking oil internally and this could indicate a damaged crankshaft, worn piston rings or cylinder walls etc. These areas can usually be repaired by qualified mechanics but sometimes they need to be replaced because of excessive damage. The mechanic needs to use special equipment while working on broken pistons so it’s always good to take your car in for inspection and get a proper diagnosis before taking any major steps towards repair.
Oil weeping from valve covers
Drop by drop, small amounts of oil may seep out from around the area where the valve covers sit on top of the engine. This is usually only a small leak and does not indicate an oil pan leak, but it can drip onto your exhaust system causing smoke when you start up your car or use the heater/air conditioner. If there are no signs of leaks around the gasket area, then keep an eye on your windshield fluid levels – if they drop regularly, then you might have very small oil seepage with no major damage to any internal engine components (if your fluid levels don’t change).
Catalytic converter or exhaust manifold gasket leaks
Any damage around the catalytic converter/exhaust manifold will cause slow-leaks and could lead to further problems down the road (e.g. expensive repairs). if you notice any seepage, then it may be coming from one of these areas rather than through your valve covers. The mechanic may need to lift the vehicle up to inspect these areas so they may also offer a service where they can carry out an inspection of your car’s undercarriage.