The 2010 Cooper with a 1.6 petrol R56 engine has an excessively high level of oil consumption.

[Howard_silver]

Greetings,

I have been researching the aforementioned prevalent problem online.

I believe the issue is in the oil control rings of the engine.

Based on my observations, driving 100 miles on a motorway often results in the use of around 500 millilitres of oil. Regrettably, I have replaced the oil separator breather, but there has been no difference. I am now contemplating the replacement of the complete valve cover with a new original equipment manufacturer (OEM) one.

When I remove the oil filler cap, I see a significant vacuum at idling.
Presumably, the vacuum level is considered normal while the engine is at idle.

According to my reading, there are two non-return valves located inside the valve cover, which have the potential to get obstructed.

I am attempting to determine if the absence of vacuum at idle while removing the oil filler cap is a typical occurrence or maybe indicative of a malfunction with the rocker cover.

The mileage is around 115,000. The engine is clean inside and there are no fault codes. However, the rear of the exhaust is covered with soot. The average fuel efficiency over the last 1000 miles is nearly 50 miles per gallon.

I would very appreciate any advise from other members. Additionally, I have seen that I own an incorrect vacuum pump, since it is equipped with a small outlet intended for the N18 engine, which is now blocked off.
I am certain that my engine is the N16.

Finally, use BMW LL04 specification oil with a viscosity grade of 5w30.

Thank you in advance

[Craigbelont]

Given the significant quantity of oil consumption, it will be necessary to do a complete engine overhaul. Components responsible for managing oil consumption in an engine are the oil control rings and valve stem oil seals. Additionally, there are several additional issues that need to be addressed when it is disassembled.

Prior to any further action, I would recommend doing a comprehensive smoke test to identify the source of the leakage and provide you with a clear understanding of the components that need to be replaced. Perform the same action on each cylinder, ensuring that the valves are closed and manually spin them. Observe whether the valves are correctly positioned and free from any carbon deposits.

[Howard_silver]

I am now considering the removal of the cylinder head and oil sump, extracting the pistons, replacing the valve stem oil seals, removing all the valves, thoroughly cleaning all components, and reseating the valves.

Prior to dismantling the engine, I want to do some preliminary tests. However, my primary objective is to determine the vacuum level at idle. It is important to ascertain if the rocker cover is functioning well. If you agree, I will proceed to immerse the pistons in a substance that has the ability to dissolve carbon deposits. Prior to commencing the disassembly of the engine, I have many tasks that I will attend to. I have previously replaced the rocker cover gasket and removed the sump to replace the oil pump solenoid. The inside of the engine is pristine. The performance is flawless, with the exception of the oil consumption problem. I want to ensure that the piston crowns are free from dirt and that the piston grooves are clean, while also ensuring that the oil control rings are not adhering or sticking. If there is no improvement, then the necessary actions will be taken, such as replacing the cylinder head, removing the oil sump, and addressing any other required repairs, such as replacing the timing chain and water pump. I will remove the engine and dismantle it, replacing any components that show signs of wear.

[Craigbelont]

It is usual to have a higher level of vacuum at idle due to low pressure. Conversely, during high rpm, there is low vacuum and high pressure.

As you correctly pointed out, the presence of carbon build-up is evident, and any method to eliminate it is beneficial. Utilising mechanical intervention would be the optimal approach, since I am unable to provide input on the aspect of additives. The primary issue with these engines lies in the use of the plastic oil control ring, which is a poorly designed component. These rings become very fragile and prone to brittleness due to exposure to high temperatures and ageing.

Please keep us updated on your progress with the chemical intervention approach - we are eager to stay informed.

[Howard_silver]

I was unaware that the oil control ring was made of plastic. It seems that the engine designers were likely aware of the flawed design.

[Matt865]

There is just one correct method to do them thoroughly, which involves completely removing all impurities and completing the task in a single attempt.

[Howard_silver]

It seems that the oil control ring around the piston is made of plastic, which is surprising. I am certain that the design is of poor quality.

[Matt865]

The rings are made of coated plastic metal nitride. If they were used in a 2-stroke engine, they would be considered the best option. I have been changing these rings for a minimum of 10 years, and they always result in a decrease in oil use, often eliminating the need for oil altogether.