
Recently, we diagnosed and replaced the turbocharger unit in a client BMW; it was an instructional case study.
Since their invention in the early 20th century, turbochargers have become ubiquitous with performance engines, heavy-duty transport, and marine applications. Over the last decade, with the growing emphasis on emissions and fuel economy, turbochargers have also found their way onto many small and medium passenger cars. When looked after, modern turbochargers are quite reliable and long-lasting, and most of the commonly cited failures are due to poor maintenance, but before we get into that, let’s take a look at how turbos actually work.
A turbocharger is an air pump that supplies air for the engine combustion process at higher pressure and density than ambient air. The turbocharger air contains a higher concentration of oxygen, allowing greatly improved combustion, more power, cleaner emissions, improved engine torque output, and reduced pumping losses within the engine, offering all-around better performance.
As an integral part of the engine’s oil, fuel, air, and cooling systems, any faults in these systems can cause incorrect turbo operation and potentially damage.
We have found that on these BMW turbos, what often happens is a failure of the wastegate system, the part of the turbocharger that controls and regulates boost pressure, keeping it in a range that offers additional performance but does not endanger the engine itself.
Lubrication – More than 90% of turbocharger failures are oil-related, either due to oil starvation or oil contamination. Blocked or leaking pipes or lack of priming on fitting usually causes oil starvation.
There are many types of contamination that may be carried by the engine oil into the turbo bearing system and cause damage. The most common are fine particles; usually carbon from the combustion process and if the concentration of these particles becomes too high, it acts a very effective abrasive, gradually eroding and polishing the running surfaces of the bearing and shaft, increasing the clearances and closing the oil feed holes, until the oil is no longer able to control the shaft. This is usually accompanied by a sharp increase in noise level and oil leaking past the turbine end seal causing oil to be burned and in vehicles without a particulate filter, noticeable exhaust smoke.
Such as poor driving habits, can result in turbo failure, so you should also consider these causes:
Hot engine shutdown can cause carbon build-up in the turbo, leading to bearing failure.
Our Goal For You and Your Car
Our goal is to save you money, not spend it. This is why each car we service gets a free Courtesy Maintenance Inspection during its first service visit. If additional work or service is needed, we’ll gladly advise you and offer a free estimate!
We aim to inform you about minor problems before they become big ones. Right now, we have several customer cars with well over 200,000 miles and several approaching 300,000! And these cars are not just limping along—most look and drive pretty much the way they came out of the showroom.
Proper maintenance is an investment in the life of your vehicle.
Knowing, not just doing, but actually knowing and understanding the difference makes all the difference.
Be sure your car is properly loved.
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