2004 BMW 745i Engine Oil Pan Replacement Cost

The engine oil pan is located on the bottom of the engine and is large enough to hold all the oil in the engine. It is bolted to the engine block, and to prevent oil leaks there's an oil pan gasket in between the block and pan. The oil pan is where the oil drain plug is located. On all engines there's an oil pick-up located in the pan that's connected to the oil pump. On some engines the pump pickup tube is also located inside the oil pan.

Oil pans don't wear out or break like other parts, they generally only need to be replaced because of external damage from an accident or an improperly tightened drain plug. The main symptom you will experience is an oil leak underneath the engine of your car. The oil that leaks from a damaged oil pan will range from dark brown to dark black. If the leak is large enough or occurs for long enough the oil level will be low enough to turn the oil pressure or low oil level warning light on.

Anytime you have an leak from the engine you want to take caution with driving the vehicle if the oil level is low to prevent damage to the engine. You will likely have a warning light come on before damage will occur however. If the oil level or low pressure light is on you'll want to get the car to a safe location off the road and ideally to a gas station or repair shop.

Engine oil pans rarely need to be replaced and they most often last for the life of the vehicle, unless outside damage occurs. They get replaced on an as-needed basis.

Oil pan issues are very easy to diagnose as the pan is easy to access and view with the naked eye. For scenarios where the oil drain plug is stripped and needs to be addressed, this too is very easy for a mechanic to visually diagnose. In some cases you could have a leak from the oil pan gasket that can be hard to diagnose, especially if the bottom of the engine heavily covered oil, grease and road grime. In these cases in can be helpful for a mechanic to add fluorescent dye to the engine oil, drive the car, then recheck for the source of the leak using a black light.

The technician will drain the oil and remove the oil pan from the engine. Removal of the oil pan may require raising of the vehicle or removal of the front subframe. The mating surfaces on both the engine block and the oil pan will be cleaned and a new gasket will be applied. Some vehicles have a paper gasket, while others may only require an application of sealant according to the manufacturer. Once the pan is installed, the engine oil will be refilled to the correct level and the technician will check for leaks to ensure a proper repair.

Whenever the oil pan is removed you should have the oil pump pickup screen checked for debris and cleaned if dirty. I If the oil pan drain plug threads are damaged, a repair shop can attempt to repair them rather than replace the oil pan.

If an oil pan is damaged from hitting something, caution should be taken to avoid driving the vehicle if oil is leaking and if an oil warning light is on, do not drive the car. If the oil pan is being replaced due to damage, the mechanic should ensure the oil pump pickup tube has not been damaged. If it is damaged it should be repaired or replaced when replacing the oil pan. When changing oil one must be very careful to avoid damaging the drain plug threads.

Replacement of the oil pan can be a very simple job or it can require major disassembly of the vehicle. On average, it takes around 4 hours for a technician to replace an oil pan. The time and effort can vary due to the access to the oil pan bolts, and the ability to remove the old pan and install the new one. On some vehicles you need to support the engine and remove the subframe to do this, so it can require special tools and abilities. If the job is straightforward an experienced DIY'er can do this, but it's not for the casual shade-tree mechanic. On vehicles where access is difficult you should leave this to a professional repair shop.