Oil is one of the three important fluids—along with fuel and coolant—that allow an automobile to operate. Oil is also one of the easiest items in the vehicle to maintain. As long as it is periodically changed, along with the oil filter, it will help keep the engine running strong. If you notice your oil leaking after an oil change, it may be because of a few reasons:
What Does Motor Oil Do?
Imagine you’re a piston head pumping up and down inside its cylinder. A mixture of fuel and air is ignited by the spark plug at the base of the cylinder, exploding in your face. The expansion of air inside the airtight cylinder forces you down with extreme force. As you drop, you drag the connecting rod with you, which turns the crankshaft attached to the mechanisms that make the axle rotate, and with it the wheels. As, you (the piston) return to your original position, you pull the rod up and turn the crankshaft another rotation. This is a simplified version of a process converting chemical energy into mechanical motion that is repeated hundreds of times every minute.
Think about what a rough life you have. High pressure gas and fuel explode next to your metal parts, blasting you through a metal tube repeatedly. In order to maintain the tight seal inside the cylinder, your head almost exactly fills it, meaning that every time you move you are sliding along its walls. Pressure, heat and friction would cause you to burn up, break into pieces or carve a groove into the cylinder if it weren’t for one thing.
Motor oil creates a thin wall of lubrication between the piston head and cylinder walls that allows the piston to move without cracking the cylinder or getting stuck in it. By reducing friction, oil also cools the chamber and aids the engine’s performance. Oil then moves around the engine, cooling other parts and carrying away impurities to be deposited into the oil filter, which cleans the oil before sending it back on its way to the engine.
Life in the Vehicle Without Oil
Here is what life inside an engine would look like without oil: The piston would melt and warp, and either crack up or begin wearing away the cylinder walls, reducing compression in the chamber. Without compression, the explosion would be dissipated in the chamber and lose some of its effect on the piston, reducing its ability to move the vehicle. The heat, no longer moderated by oil, would build up to levels that couldn’t be tolerated by the metal parts and they would begin disintegrating. Without a flow of oil around the rest of the combustion chamber, other metal parts would begin warping as well. The whole engine would eventually seize up.
It wouldn’t be a pretty picture.
That is why it is so important to maintain oil levels and get new oil in the car at recommended intervals. The life of your vehicle literally depends on it.
Why Is There Oil Leaking in My Car?
Because oil is the life blood of a vehicle, experiencing an oil leak in a vehicle is a cause for immediate action.
There are a variety of reasons a vehicle might leak oil. The two most obvious are an oil filter that isn’t affixed correctly and an oil drain plug that isn’t sufficiently tightened – or tightened so tight that it cracks. Cracks, holes or corrosion in the oil pan can cause oil to drip down to the ground. If you have an oil leak, these are the options you hope for because they are simple to fix.
The oil leak might also be caused by worn rings, valve seals or gaskets at various positions under the hood. These items are designed to create airtight seals where needed—for example, next to the combustion chamber where fuel and air are ignited by a spark to propel the pistons. When oil leaks into the combustion chamber, it can interfere with the ignition process. Manufacturers provide specifications for the proper amount of torque to be applied when tightening gaskets to avoid slippage and cracking.
Why Is My Oil Leaking After an Oil Change?
The good news about oil leaks following an oil change is that the most common causes of this type of leak are easy to find and fix.
Double Filter Gaskets
The most common problem immediately following an oil change is that the oil filter gasket—a black rubber o-ring—remained stuck to the engine when the old filter was removed. When the new filter was mounted with the new gasket, the resulting double gasket created a poor seal and leaking resulted.
Before removing the oil filter, drain the oil from the oil pan. Once there is no oil in the system, simply removing the oil filter and peeling off the old gasket will resolve this problem. Have something to catch dripping oil when the filter is removed to avoid making a mess.
Bad Filter Installation
There are a variety of ways to install the new oil filter wrong, beginning with installing the wrong type of filter. Double-check that the filter is designated for the specific make and model of your vehicle.
If that isn’t the problem, the filter may be attached incorrectly, over- or under-tightened. Oil filters should be tightened by hand until they resist and then tightened one-quarter turn more to securely fasten them. Anything less creates a loose seal and anything more risks crushing the filter head. Never tighten an oil filter with a filter wrench. That tool is designed only to remove filters.
The oil filter is sturdy, but the screw threads that allow it to screw onto the engine are soft and prone to stripping. This can be tested by grasping the oil filter and determining whether it is a tight fit. If the threads are damaged, the oil filter must be replaced.
Under- or Over-Tightening the Drain Plug
Over-tightening the drain plug on the oil pan is a common issue because it is so easy to do. The drain plug should be hand tightened and then finished off with a wrench, but only until it is secure. Tightening it beyond that can crack the plug and even the drain pan itself.
It is also possible to under-tighten the drain plug. This is simply corrected by using a wrench to tighten it a bit more, again, just until it is secure.
If the plug is too tight, loosen it a bit and see if that fixes the problem. If it is beyond redemption, drain the oil and replace the plug and gasket. They cost a couple of bucks at an auto supply store.
How Do I Know I Have an Oil Leak?
There are a handful of clear indicators that oil is leaking. The one that can be seen from inside the car is the oil warning light on the dashboard, which reports that the oil level in the vehicle has dropped to the point where it may affect the functioning of the engine. Because this indicator only comes on when the oil level has dropped quite low, it is preferable to find the oil leak before the warning light flashes on your dash.
The best indication that oil is leaking is a greasy brown fluid on the ground beneath the vehicle. (If the liquid is pink, you have a transmission fluid leak and if it is green you have a coolant leak. Those are also serious and should be dealt with ASAP. Finding oil on the ground suggests not only an oil leak but its location. It is easy to trace a leak from the oil pan or oil filter as the puddle develops directly beneath them.
Oil leaking from a seal is more difficult to trace. Sometimes it is possible to smell the oil being burned under the hood as it sits on hot engine parts. Oil being burned as part of the combustion process will be emitted with the exhaust. It may be possible to smell that as well, or see abnormally thick or blue smoke emanating from the exhaust pipe.
A Permanent Fix for Some Oil Leaks
A short-term fix that buys time by addressing the symptom is to add oil to the crank case to replace the oil lost. For small, slow leaks this can work fine, except for the environmental damage of leaking oil onto the road or burning it and emitting it into the air.
If the problem is a bad seal or a hole in the oil pan, adding a bottle of BlueDevil Oil Stop Leak offers an inexpensive fix if you are unable to take your vehicle to a mechanic or fix the cause of the problem yourself. The non-clogging formula is kind to gasoline and diesel engines and seals small leaks permanently. It also serves to repair and recondition rubber seals and gaskets throughout the system.
To use BlueDevil Oil Stop Leak, just pour a bottle slowly into the crank case and run the engine for an hour or two until the leak stops. Oil Stop Leak can be used for pinion seals, gear cases, shock absorbers, gear boxes, axle seals and gear differentials as well. Just take care not to use it in brake systems or on painted surfaces.
If you had an oil change done on your car by a professional and it starts leaking, take your car back and have it fixed. Oil leaking after an oil change is not normal and needs to be addressed.
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