BMW Timing Chain Diagnosis & Repair
If you own a BMW model from any of the BMW 1, 3 or 5 series manufactured between 2007 and 2011 then your car is liable to have a timing chain problem. The luxury German machines are prone to a specific engine problem, a timing chain wear owing largely to the use of the newer N47 motor engine.
How can you tell your timing chain is faulty?
The most common sign of a faulty or slacking timing chain is a rattling or clanking noise with sometimes heavy vibrations coming from where the timing belt is placed, the rear of the engine. The positioning of the timing chain remains a fundamental flaw in the engineering design, a major contributing factor to the wear of the chain. In some cases, BMW owners may notice an illuminated ‘check engine light‘, a sign that the engine is not running properly. This is often followed by the car coming to a grinding standstill, necessitating a tow to an automotive repair shop.
What causes the timing chain to snap?
As mentioned earlier, the positioning of the timing chain leaves it vulnerable to unusual and premature wear and subsequent failure of the engine. Failure of the timing chain tensioner could leave it broken or snapped. The timing chain is a toothed metal chain solely responsible for holding the engine components together to run in perfect sync. As the primary component linking the moving engine parts, once the timing chain slacks, most of the parts now dislocated may go hurtling into one another, recklessly colliding and causing immense damage to the engine such as engine valve damage, ruined cylinder heads, piston damage and in severe cases, a total engine breakdown.
How do we replace a broken timing chain?
Here, what we usually do is to first turn off the engine, that is if the car owner had not already done that. The timing chain is located in the rear end of the engine, an area that was not designed to be serviceable. Thus to fix the broken timing chain, more often than not, we would have to remove the entire engine. In a case where the timing chain snapped due to a failure of the timing chain tensioner, noticeable damage may occur to the plastic guide rails the chains are designed to ride on. These guides need plenty of fresh oil to keep it lubricated to function properly, hence this will necessitate an oil change and further inspection. Beyond replacing the chain itself, we will also replace the timing chain tensioner, and for engines with more than one tensioner, we place the whole set at once.
In certain cases, the damage to the mechanical parts in the engine may be minimal so all we may have to do will be to change the timing chain with a little servicing. However, other cases come with a massive engine damage that may require a complete overhaul of your BMW engine. Generally, considering the location of the timing chain, replacing the chain often entails the replacement/servicing of other connected mechanical components. These components usually include the tensioner, the water pump, cam seals and plastic guide rails.
However, you shouldn’t wait until your timing chain is broken before you fix it. It’s recommended that once your car has hit a mileage of 40,000 to 100,000 you should have your timing belt replaced. Also, regular maintenance checks and service can be the difference between a towed car and a good running vehicle. The more miles clocked without servicing, the more susceptible your timing chain is to breaking. Remember, the slightest disruption to your timing chain could affect your entire car engine.