Here is a perfect example of how to fix a serious problem with a little cleverness.
A 2013 BMW – X3 came in the shop today, with the usual timing chain issue. The engine stopped due to the timing chain literally jumping over as the guides shared off from the chain rattling around loose already.
Unfortunately the center guide rail got jammed between the loose chain and a broken guide piece breaking the upper support of the chain guide which is part of the camshaft journal and not sold separately. In fact it is part of the cylinder head so replacing it would require a another cylinder head to resolve.
We decided it would be just as good of a solution to weld the broken piece by a professional welder and I made an additional stainless piece to give it extra strength so this would never break ever again.
We could have said to this client sorry not much we can do in here, other than replace the cylinder head.
However we found a solution, this is what we are good at trying to find an affordable and reliable solution to the problem at hand.
The red arrow on the top, bigger photo is pointing to the broken camshaft journal end. On the other pictures it has been weld and reinforced.
The weakest link on the BMW N20 engine is a common timing chain failure, due to the guides breaking from the chain oscillations. The timing chain in most cases will rattle, oscillate wildly and in the process will break pieces off the chain guide, which will get picked up or sucked up by the oil pump which destroys the engine suddenly in the process.
The broken guide pieces may block the entire pick up screen for the engine oil pump which will seize or destroy the engine components, due to sudden lack of lubrication.
The real cause in my opinion is the ECO mode which is the default mode in the transmission after every single start of the vehicle. The chain oscillations are caused by the transmission selecting the highest possible gear with the lowest possible engine rpm to maximize the efficiency of the engine as it has been mandated by the CAFE (corporate average fuel economy in short). We had the first stage of the CAFE mandated for 2016 the next stage is proposed for 2025. The real issue at hand unfortunately is the 8 speed automatic transmission, which is programmed to provide the best possible gas mileage, which in this case is counterproductive as it will lag the engine at very low rpm to minimize fuel consumption and to maximize the efficiency of the engine.
BMW N20 engine repair because of timing chain failure.
The N20 will fire at every half turn which is 180- degrees this will (two full turns equates to 720 degrees for all the 4 cylinders to be fired) which is problematic for the single row timing chain. I can tell you from the past, the last generation 4 cylinder sold in this part of the world was the M44 (before was the M42) which had a dual row chain to prevent this issue to happen. So why did they switch to a single row timing chain system you may ask?
This is all done to maximize efficiency and to reduce the internal drag of the engine and it’s components. Back then there was no CAFE standards, manufacturers were left to build whatever they deemed fit for the purpose.
This cars are equipped with a standard transmission in Germany, so they will get a work out when they are driven to the Autobahn. In North America every one of these cars are equipped with an 8 speed automatic transmission.
How can you prevent this problem? We recommend to flip your selector to sport mode after start and don’t be afraid to give your engine a work out, after all it was built for the Autobahn. You can switch back to ECO mode to reduce the fuel consumption, when you drive on the highway at higher speed.
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This cars are meant to be driven spiritedly on the Autobahn. This doesn’t mean you have to drive it all the time as a maniac, it means keep the rpm at least medium or higher much as you can. Naturally always use proper oil and filter, at more frequent intervals, than recommended by the manufacturer. You won’t believe how many inferior oil filters we find and replace on this cars where they got some cheap inferior filters installed elsewhere.
In case you are interested in a ECO car you may want to consider an i3 or other hybrids, perhaps a hybrid BMW and or a Prius.
You also should have your vehicle serviced by a specialist, a BMW technician, so we can give you an early warning which may prevent permanent engine damage. There are tell-tale signs of this issue for a trained seasoned BMW technician, this is what we are good at. We’re working on European cars since 1976.
Any questions, how may we help? Give us a call to: 905.795.0419!
Here is a perfect example of a BMW N20 engine failure because of the lack of maintenance.
You can see on the third image, a bunch of granulated pieces and metal shavings, which resulted in a broken timing chain guides and chain failure. If you want to prevent this from happening, change your oil at minimum once a year or ten thousand kilometers.
Also try to forget about the ECO mode put your gear selector into sport mode and leave it in there.
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If you need any further information I will be happy to explain in person, how may we help? Give us a call to: (1) 905.795.0419!
Timing chain replacement for a 2013 BMW 550xi due to broken chain guides and jumped timing chain which resulted in an undriveable vehicle.
Engine work on 2013 BMW 550xi
We received this beauty from the local dealer where at the owner has been told, to properly diagnose the problem at hand, will cost him 3500.00 dollars. Which is somewhat understandable since to achieve anything on this N63 engine, it must be removed to gain access to the vital components. It’s worth to note, this vehicle had only 78 thousand kilometers in. The question is; Why this happened? The answer is actually two fold. The number one issue is, it has been driven ultra short distances, from home to work and back, 8 km either way.
The second issue has been, this particular chain design is an early version of a toothed chain design, which was unproven at the time.
Ladies and gentlemen this engine was built for autobahn speed, where it gets a work out, this modern high tech engines designed and build for a certain purpose, that’s the way they should be driven.
Low tension, low friction piston rings will allow more blow by especially with a cold engine, condensed water will be collected in the motor oil and will have no chance to boil off. Consequently, will damage the internal components.
Naturally we have done a lot of additional repairs on this car, like cleaned the intake valves and replace all the components with new revised versions.
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There are multiple factors contributing to this problem, not withstanding the 8 speed automatic transmission is one of the factors in my opinion. North American drivers prefer their cars to be automatic, in this case, the automatic is more economical, than the standard version which is preferred by the Europeans.
You may ask; Why is there a problem with the 8 speed automatic? The problem occurs with our driving habits and the programming of the automatic transmission. In normal ECO mode (the default mode) it will shift up quickly and efficiently to the highest possible gear to keep the fuel consumption at minimum, hence called the ECO mode.
4 Cylinder BMW N20 Engine
The quick up-shifting in daily driving will keep the engine’s rpm very low, which will cause the 4 cylinder engine to oscillate a lot more than would have been, if it driven on the autobahn at high rpm, where there are no oscillations are really present.
Naturally the chains, the guides are fairly weak design to make them light as possible. Our stop and go driving at low engine loads paired with an efficient automatic exacerbates the problem. Furthermore the extended oil changes also does not help to keep the whole thing properly lubricated for long life.
Needless to say the newer engines and their timing chains has been extensively redesigned to counter this common and often fatal problem.
In any case, if the chain makes noise it must be addressed immediately. All the components has to be replaced. For replacement, only an improved version available from the manufacturer. The replacement components must include the oil pump drive assembly as well, according to BMW repair instructions, also a revised, improved component.
There are multiple special tools required and attention to detail is essential to complete this rather delicate repair procedure properly and permanently.
You can see on the above photo a broken timing chain guard and a clogged oil pump pick up, which could be fatal to the engine.
In case you have any additional questions please don’t hesitate to ask. We are here to help. Thank you for your time and all the best.