Common Issues: Premature timing chain failure.
Here at MJR MiniMatt one of the most common issues we see is noisy or premature timing chain failure. This is particularly problematic on the R56 Mini 2007-2013.
Before we delve in to the possible causes and solutions for this common problem let’s have a quick look in to what a timing chain is, what it does and what happens when one fails. We’ll try to keep the technical stuff to a minimum!
What is a timing chain?
An internal combustion engine can essentially be split in to two halves: The top half consisting of the cylinder head which houses the camshafts, inlet and exhaust valves and the bottom half is the engine block, this houses the crankshaft and pistons. A timing chain, which is very similar to the chain you would find on a bicycle, links these two halves so that they rotate in sync with one another precisely. If the cylinder head and crankshaft run out of sync then this is where potentially serious problems occur.
More and more vehicle manufacturers are moving away from the conventional timing belt arrangement in favour of timing chains. This is mainly down to supposed reduced service intervals compared to timing belts. We will explain more about servicing and timing chain intervals later on.
What are the symptoms of a faulty timing chain?
Difficulty in starting the engine
Misfiring: Fuel is not being ignited causing it to detonate in the exhaust or inlet
Lumpy or rough running
Those are the main symptoms of a faulty timing chain. Another is a noisy engine that has a very loud rattle when running, otherwise known as “The Death Rattle.” This is more often than not down to a failing timing chain tensioner. This component is responsible for keeping the timing chain under the correct tension to ensure the precisely synced rotation of the camshafts and crankshaft.
In the early R56 engines this was usually down to the original timing chain tensioner that was used by the manufacturer. This tensioner had design flaws and began failing prematurely causing the “Death Rattle.” The manufacturer subsequently redesigned the tensioner addressing these flaws so with a straight forward updated tensioner replacement the problem was solved.
So why are we still seeing cars with “Death Rattle” after installing the updated tensioner?
This is down to servicing and maintenance, or lack thereof. This particular engine uses oil so it is vitally important the level is checked and topped up with the correct grade oil on a regular basis. The timing chain tensioner is hydraulic: oil is fed in to it under pressure forcing the tensioner to push against the chain at the correct tension keeping everything running in sync as it should. When the oil level is below the minimum requirement, oil pressure is reduced in turn reducing the pressure the tensioner is exacting on the timing chain. The result of this is the chain goes slack, jumps teeth on the timing gears or completely flies off all together.
As we mentioned earlier the two halves must run in sync at all times, once the timing chain has left the building havoc is wreaked on your poor engine’s internals. The pistons collide with the inlet and exhaust valves bending them irreparably, from the impact the pistons can be destroyed and, in some cases, due to the extreme forces involved inside an engine the impact of the pistons can crack the cylinder head condemning it to the big scrap yard in the sky. Now a hefty repair bill awaits.
If this unfortunate event happens to you then get in touch with us. Here at MJR MiniMatt Ltd we can save your pride and joy from the clutches of the scrap yard! We offer a full repair service of your engine, this involves stripping it down, removing and sending the cylinder head away to a team of engineers who will replace any damaged parts. We then reinstall the cylinder head along with a brand-new genuine timing chain kit with uprated tensioner. The end result is your car is back on the road and running better than it ever did!
What can I do to prevent this happening to my car?
At MJR MiniMatt Ltd we believe in preventative maintenance so CHECK YOUR OIL LEVELS! Now this may sound obvious to most people, but many do not do this most simple and crucial check to ensure the longevity of their engine. As outlined above, these engines use oil so checking the dipstick should become as much a part of your routine as brushing your teeth!
Keep up with the manufacture prescribed service intervals. This is another vital component of keeping your pride and joy healthy and happy. Missing the service intervals will harm your engine as the oil has come to the end of its life and its properties are no longer what they used to be and are not protecting your engine’s vital organs as they once did.
The manufacturer’s service intervals for these engines are:
15,000 miles or two years whatever comes first.
From our experience, we recommend service intervals of 10,000 miles or twelve months. We believe the vehicle manufacturer’s recommended intervals are too long between services due to the fact these engines have a drink problem. They use around one litre of oil every 1,000 miles this is what the vehicle manufacturer considers an acceptable tolerance. These engines can use double this if not more!
There isn’t a service interval for the timing chain set by the vehicle manufacturer as they’re designed to be a lifetime part. Lifetime is a bit of a misnomer; the vehicle manufacturer’s definition of lifetime is four years. Yes, four years pretty short life! This is their warranty period.
If the car is looked after and serviced correctly then there is no reason why a timing chain couldn’t surpass 200,000 miles without changing. We have seen them failing as early as 40,000 miles, again due to poor servicing and lack of basic maintenance. If your car, to your knowledge has never had a timing chain and the service history is not complete or missing all together, then it would be best practice to get it inspected. We will be happy to have a look at your timing chain and advise you of the condition of it along with the best action to take to keep you on the road.
So, making your service intervals more frequent as we recommend, will ensure the longevity and smooth running of your pride and joy avoiding catastrophic premature timing chain failure. These engines are designed to recirculate exhaust gasses to meet the very strict emission regulations. Regular servicing aids in keeping everything as fresh and as clean as possible on the inside, preventing the coking up of the cylinder head and keeps the valve stem seals in good order this reduces the common smoking problem. This is again an expensive repair as the cylinder head has to be removed in order to renew them.
We also offer a three Stage BG oil treatment this involves an engine flush, petrol or diesel additive and an oil additive. The three used together help keep your engine clean and protected. This treatment costs £60.00 including VAT on top of your regular service. Check them out here https://www.bgprod.com/ for more information.
Here at MJR MiniMatt we use Petronas oils- if it’s good enough for Lewis Hamilton’s Mercedes Benz Formula One car then it’s good enough for ours! We also only use genuine parts this ensures that what we use are the same or exceed the vehicle manufacturer’s specifications, giving you piece of mind that only the correct parts and the best parts are fitted to your car at a fraction of the cost of brand dealerships. Click this link https://www.pli-petronas.com/uk to find out more about Petronas oils.
We hope you found this article interesting and informative and we are looking forward to bringing you blog posts on a regular basis with more hints and tips for your Mini or BMW.
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