The BMW N47 is an Inline 4-cylinder diesel engine that has been installed in the BMW 1, 2, 3 and 5 series, respectively X1 and X3, diesel variants from 2007 to about 2014. This engine is prone to excessive timing chain wear and premature failures.
The timing chain in this engine is placed at the rear side of the engine and is sandwiched between the engine and the transmission. Being at such an inaccessible place also makes its replacement not an easy task. Parts normally installed in such inaccessible places are designed to last for the life of the engine, but not in this case. The timing chain in the N47 can fail anywhere between 40 to 100k miles and can cause serious damage to the engine as its parts loose the synchronization.
Most of the times when the timing chain breaks off inside the engine it also damages the engine components with it, which leads to huge repair bills. This problem can also be diagnosed prior to its complete failure by looking out for a rattling noise from the rear side of the engine.
The timing chain being at such an inaccessible place requires the mechanic to take out the engine completely from its bay to get a good access to the chain. Taking the engine out is itself a big and hefty task. After that it is another hefty disassembly that provides you access to the chains themselves
The timing Chain replacement kit consists of 3 chains, for the oil pump, camshaft, and the high-pressure fuel pump. You also need to have the looking tool kit to lock the crankshaft and camshaft in their place while working on them so that they do not lose the synchronization. After getting the engine out from the bay these are the major steps that must be performed to replace the timing chains.
- Firstly, ensure that the cylinder 1 and 4 are at top dead centre, to maintain the point for synchronizing the points in accordance with it.
- Lock your crank shafts at this place with the looking tools you have.
- Take the tensioner for the camshaft chain out to loosen the chain a bit and loosen the 3 bolts on the camshaft sprocket.
- Loosen the high-pressure fuel pump off, it will make the processes of getting the fuel pump sprocket off easier.
- Take out the bolts holding the fly wheel and get the flywheel off the crankshaft.
- Undo the bolts of the starter motor to further get access to take out the oil sump out.
- Take the oil sump out by undoing the corresponding bolts.
- Now take the timing cover out by undoing the bolts holding it in place. It will require a bit of prying and light taps from the hammer. Now you will get access to all the chains and sprockets.
- Now remove the oil pump sprocket and the guides for the oil pump by undoing the bolts. And remove the chain for the oil pump.
- Similarly remove the guides and tensioner for the camshaft sprocket and take out the sprocket along with the belt.
- Now rotate the crankshaft 45 degrees after TDC and undo the tensioner, guides, and sprockets for the high-pressure fuel pump. Take the belt along with the sprockets out as well.
- The last thing would be your oil sprayer, you can remove it for replacement if needed.
- After that place in the new belts in the reverse order ensuring all components remain in sync till the end.
This timing chain issue is a critical flaw in the engine’s design and the best way to solve it is to avoid the cars with this N47 engine or get rid of it in running order if you can. As this engine also faces many problems due to the emission control devices installed in it such as the EGR and DPF.
We recommend you to read more details regarding the BMW N4 engine problems in our article below: