From 2007 to roughly 2014, the BMW N47 was an inline 4-cylinder diesel engine that was utilised in the BMW 1, 2, 3, and 5 sequence, as properly as the X1 and X3 diesel versions.
The N47 engine sequence is vulnerable to early timing chain failure owing to critical timing chain use. The circumstance is indicated by a rattling noise coming from the engine’s rear. Failure of the timing chain may necessitate motor replacement or a high-priced restore. The dilemma influences all apps and ability variations of the engine manufactured among March 1, 2007 and March 1, 2011. The most seriously weakened models, which require the most sizeable repairs, have been produced in between the dates of 01.03.2007 and 05.01.2009. UPDATE – It seems that a tiny range of engines built following the remember are acquiring troubles.
The timing chain on this motor is sandwiched between the motor and the transmission at the again of the engine. Its replacement is particularly hard simply because it is situated in these an inaccessible location. In most scenarios, pieces put in in these types of inaccessible places are meant to survive the daily life of the engine, but not in this circumstance. The timing chain in the N47 can are unsuccessful everywhere from 40 to 100k miles, producing catastrophic motor problems as its factors eliminate synchronization.
Diagnosis – Signs and symptoms of a Failing Timing Chain
The signs and symptoms of a failed timing chain normally show up slowly as the chain gets for a longer time and more worn. As a end result, you’re not likely to detect a sudden extraordinary symptom until finally the chain is in the vicinity of to crack totally. As an alternative, assume about how your car is accomplishing currently and how it done quite a few months in the past. Small troubles could counsel that the chain is about to are unsuccessful wholly.
Below are some of the signs that your timing chain is failing:
- Rough idling: Get started your car and walk absent. It is probable that the timing chain is putting on out if it shakes or vibrates far more than typical. Of course, there are other troubles that could outcome in severe idling, but the problem is normally truly worth investigating mainly because it tends to worsen around time.
- Odd noises: You might hear your N47 motor rattle, especially when it’s idling, but not only when it is idling. The situation could be that the timing chain is loose and rattling from anything else if the seem is persistent and rough.
- Steel shavings in the oil: Over time, the timing chain will put on down. When it reaches the close of its valuable life, it may perhaps emit steel shavings. If it does, it will close up in your motor oil, probably producing further more issues. However, any worn-out part of your car can generate metal shavings, so it is worth on the lookout into ahead of merely replacing the chain.
- Engine failures: If your BMW would not start, the chai may be weakened and not giving enough tension to begin the engine. If the chain breaks while you are driving, it’s feasible that the timing chain has damaged as nicely. If this occurs, the pistons might be damaged, and the belt issue may possibly result in more problems to your vehicle.
- Engine misfires: Your N47 motor could misfire ahead of the chain has totally snapped. The cam and the crankshaft are joined by a chain. The chain might induce the car to skip a gear on possibly the crankshaft or the camshaft if it is overly stretched out. It will develop into far more pressured as a consequence of this, and it will ultimately crack.
- Examine engine light-weight is on: Of system, the test engine light-weight could sign a massive range of points have gone mistaken with your BMW. On the other hand, it is possible that the timing chain has failed or is shortly to fail.
Substitution and Repairs
For the reason that the timing chain is in these kinds of an inaccessible area, the mechanic have to totally get rid of the engine from its bay to get obtain to it. Using the motor out is a substantial and tricky enterprise in and of alone. Following that, yet another prolonged disassembly is essential to get entry to the chains by themselves.
Three timing chains are incorporated in the timing chain alternative kit: 1 for the oil pump, 1 for the camshaft, and one particular for the large-stress fuel pump. You will also will need the on the lookout software package to maintain the crankshaft and camshaft synchronized even though you are performing on them. These are the main duties that have to be accomplished after eliminating the engine from the bay in order to change the timing chains.
To begin, make guaranteed that cylinders 1 and 4 are at prime dead heart in get to retain the issue for synchronizing the details.
With the instruments you have, lock your crank shafts at this spot.
Get rid of the camshaft chain tensioner to loosen the chain a minimal, and loosen the three bolts on the camshaft sprocket.
It will be easier to take out the gas pump sprocket if the higher-force gas pump is turned off.
Clear away the flywheel from the crankshaft by eliminating the bolts that maintain it in location.
Get rid of the starter motor’s bolts to acquire accessibility to the oil sump.
By undoing the necessary bolts, you can remove the oil sump.
Clear away the timing cover by loosening the nuts that keep it in location. It will take some prying and a number of gentle taps with the hammer. You can now accessibility all of the chains and sprockets.
By loosening the bolts, you could now take out the oil pump sprocket and the oil pump guides. Take away the oil pump’s chain as properly.
Equally, remove the camshaft sprocket’s guides and tensioner, as nicely as the sprocket and belt.
After TDC, twist the crankshaft 45 levels and take out the high-stress fuel pump tensioner, guides, and sprockets. Just take off the belt and the sprockets as nicely.
The previous merchandise is your oil sprayer, which you could take away for replacement if important.
Then, in reverse order, put in the replacement belts, making sure that all parts are in sync right until the conclusion.
This timing chain difficulty is a design and style flaw in the engine, and the only strategy to cure it is to stay clear of automobiles with this N47 motor or, if doable, get rid of it in functioning purchase. Mainly because of the emission control gear put in it, this sort of as the EGR and DPF, this engine also has a lot of troubles.