Hello everyone, this is a column focusing on car repair and maintenance. There are car mysteries you don’t know, and it will teach you how to avoid the big pits on the road of car ownership. I believe that not only you but also many people have a certain sense of obscurity about the car aftermarket, which will help you uncover the unknown stories of car repair and maintenance.
The MINI, which has traveled nearly 150000 kilometers, has also begun to burn engine oil, and a puff of blue smoke from the exhaust pipe will be clearly seen when it starts in the morning. And this kind of blue smoke will disappear with the rising temperature of the engine after starting, which is the typical phenomenon of valve oil burning.
As the only medium for the connection between the engine valve chamber and the combustion chamber, the state of the valve oil seal will directly affect the oil consumption of the engine. Too much clearance of the valve oil seal causes the oil to flow directly into the combustion chamber along the gap, and the engine will be burned off along with the mixture while the engine is working.
The valve oil seal is inside the valve chamber. Removing the valve chamber cover is the first step. After opening the valve chamber cover, the engine can be said to be a dirty mess, obvious poor maintenance, and the oil inside the engine feels very oxidized. Good oil has excellent cleanliness and will never be what it is now.
It is necessary to disassemble the valve oil, so there is no need for me to say the importance of timing. So at the oil pan of the engine, there is a clip pin specially installed on the flywheel to fix the crankshaft.
To remove the camshaft, the double overhead camshaft is easy to disassemble, but there are relatively more bolts. When disassembling, be sure to pay attention to the removal sequence of the bolts and relax them from both sides to the middle. If not, the powerful valve spring is likely to break the camshaft.
This is the camshaft that has been removed, on top of this N14 engine. Only the camshaft on the intake side has a variable timing system. In current terms, there is not so much technology, just like Tony who has just completed a primary model of Iron Man in the desert. Less technological equipment means more stable reliability. Yes, you don’t have to worry about the sticking fault of the motor in the valve lift at all.
After dismantling the camshaft, I have to say that the oil is really dark. I saw obvious sealant marks on the valve chamber cover. The engine must have been repaired before, but it is not known exactly what has been replaced.
The traditional method of replacing the valve oil seal is to remove the cylinder head of the engine and then replace the valve oil seal. Now there are special tools that can remove the valve oil seal even without removing the cylinder head.
This is a very common tool that has been around for decades.
The old valve oil seal that has been removed is not bad, but it can no longer be used because the gap has become so large. (up to now, I have almost thousands of valve oil seals.)
To make a comparison between the old and the new, you can see that the clearance of the old valve seal is obviously larger than that of the new one. This gap leads to poor sealing of the valve seal, and the oil goes directly to the inside of the cylinder along this gap. This is where the blue smoke came from when it started.
New sealing ring ~
Install a new valve chamber cover gasket, the original factory seal gasket texture is very good, directly installed in place.
The whole process of replacing the valve oil seal lasted nearly 6 hours. Although it is easy to see through the picture, the whole process takes a lot of time to clean up.
MINI’s excellent appearance and very good manipulation have been favored by many minority players, but the failure rate is slightly higher, which is probably very difficult for people with obsessive-compulsive disorder. Seeing that BMW is going to launch an electric MINI, it really chills my heart. I wonder if MINI can still be called MINI without the roar of the engine.
DeanMorrison 
3 
September 9, 2024 
