BMW M57 Engine Problems: There are not a lot of engines that accompany cars from the late 1990s model years and up to the early 2010s. Well, the BMW M57 diesel engine sure is one of them.
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The production of the M57 started in 1998 and lasted until 2013. It is commonly referred to as one of the best diesel engines ever made and rightfully so. It came in various setups from the early simple forms in the E39 BMW and in a twin-turbo setup fitted later to the E60, E90 and the E63 6-Series.
The basis of the engine was and still is fantastic which allowed BMW to use the platform for various cars and power outputs. But just like many other great diesel engines (like the OM642 or the OM651 from Mercedes), the M57 carried its own set of problems.
Here are the most common BMW M57 diesel engine problems that are known today!
Which BMWs have the M57 engine?
The M57 engine was fitted to a lot of BMW models until the N57 diesel engine, which was lighter and more environmentally friendly took its place. Here is a table that features all the BMW models with this engine.
|Engine Variant||BMWs With This Engine|
|M57D25||2000-2003 E39 5-Series 525d 120kw|
|M57D25TÜ||2003-2007 E60/E61 5-Series 525d 120/130kw|
|M57D30||E39 530d (135/142 kw), E46 330d (135/142 kw), E38 730d (135/142 kw), E53 X5 3.0d (135 kw)|
|M57D30TÜ||E46 330d – E83 X3 3.0d (150 kw), E53 – E60/E61 – E65/E66 – E83 as 3.0d with 160 kw|
|M57D30TÜ TOP||E60/E61 – E63/E64 as 3.5d with 200 kw|
|M57D30TÜ2||E90 – E60 as 2.5d with 145kwE65/66 – E90 – E60 with 170kw as 3.0dE60/61 – E70 – E71 with 173 kw as 30d|
|M57D30TÜ2TOP||E60/61 – E63/64 – E70/71 – E83 – E90/91/92 with 210kw as 35d|
Common M57 Engine Problems
Do not get scared by the list before you, the M57 is still a solid engine and many of the things listed below are just nuisances you eventually have to take care off as these cars reach high mileages.
Certain problems can also be prevented in order to avoid bigger M57 engine problems in the future, so be on the lookout for that!
Heavy Carbon Buildup Problems
Many owners of the M57 engine experience serious problems with carbon buildup in the engine. In this E90post forum thread, it is evident that more than 67% of M57 owners do experience problems with carbon buildup.
Carbon builds up in the engine as a consequence of clogged EGR valves. The EGR contains carbon soot which catches up with the oil vapors /gasses coming from the positive crankcase ventilation (PCV).
These PCV gasses used to be emitted into the atmosphere but for environmental reasons, modern diesel like the M57 burn these gasses internally.
As the system becomes polluted, oil and PCV vapors form carbon deposits on intake valves and the intake manifold which leads to loss of power, rough idle and eventual engine problems, error codes and limp mode.
To avoid these problems, although not recommended and allowed in many countries due to strict emissions testing, many owners delete the EGR valve or install an oil catch can that captures the PCV vapors, preventing them from polluting the engine.
M57 Intake Manifold Swirl Flaps Problems
One of the most common and serious M57 engine problems are the poorly designed intake manifold swirl flaps.
Due to the poor design and carbon buildup on these flaps, these flaps have a tendency to detach, break off and get sucked into the cylinder heads.
This leads to serious engine damage and repair costs that are insanely high.
Although BMW introduced an improved swirl flap design in 2006, many owners still do not trust this system which is why a “swirl flap delete” procedure is extremely common on these engines.
Swirl flaps slightly improve the fuel economy of the engine and the low rpm range torque, but the benefits are far smaller than the potential damage if the flaps fail and get sucked into the engine. If you are buying a car with this engine, we recommend you have them removed, regardless of the model year of the engine.
MAF Sensor Failures
A lot of owners report common mass air flow sensor failures (MAF). The MAF sensor measures the amount of air entering the engine in order to provide the right mixture of fuel/air for the combustion process.
This leads to rough idling, hard startups, engine stalling and jerky or hesitant acceleration. A new MAF sensor costs anywhere from 130-200$ and it is easily replaced.
The M57 engine is known to have problems with the thermostat, however, there are no issues with the water pump as is common on other BMW engines, like the N53.
The thermostat on the M57 is designed to fail in the “open” position which means your car will have a hard time warming up to the normal operating temperature.
The failed and opened thermostat will provide a constant flow of fresh coolant to the engine which is far better than having a thermostat fail in a close position which causes the engine to overheat in a matter of minutes.
In many cases, a failed thermostat also triggers error codes and the check engine warning light if the owner does not recognize the signs of failure.
M57 DPF/SCR problems
As with other modern and seemingly environmentally friendly big diesel engines, there are more issues with DPF and Selective Catalytic Reduction (SCR) systems than there are with the engine itself.
A lot of M57 engine owners have to deal with clogged DPF filters that come up because the car makes many short journeys or the driver unknowingly interrupts the DPF regeneration.
There might also be other underlying reasons (sensors, software…) why a DPF filter is not properly regenerating and is getting clogged.
The same goes for the SCR system. Many owners experience nightmares with SCR system failures such as the active tank failure, tank heater element failure, NOx sensor failure and so on.
The amount of potential trouble and costs are enough to convince many owners to do a complete DPF and SCR delete. However, deleting these components is not possible in many countries due to strict technical inspections.
EGR Cooler (Cracks) and EGR problems
We already mentioned that the EGR valve on the M57 and basically all other modern diesel is prone to clogging and eventual failure. One of the very specific to the M57 engine problems are the cracks in the EGR cooler.
A crack in the EGR cooler is easily diagnosed by a strong diesel odor around the car and in the interior of the car. The cooler is known to crack in several locations, including the pipes leading to the cooler.
The EGR cooler is again a component of the emission reduction system and your car can easily run without both the EGR valve and the cooler.
Many owners do this “delete” procedure but we would not recommend it.
Glow Plug Failures
The glow plugs on the M57 need replacing after approx. 100,000 miles or 160,000 kilometers. The glow plugs tend to fail earlier if there is an undiagnosed thermostat failure. In some cases, the glow plug controller also needs to be replaced.
Bad Vacuum Lines
As these engines age, the various vacuum lines around the engines tend to become brittle and leaky.
A vacuum leak leads to specific vacuum sounds, engine warning lights, rough idling and hesitant acceleration. Finding the leaks is the hardest part, replacing them is easy and inexpensive.
Harmonic Balancer Failures
Harmonic balancers in a car absorb and remove excessive vibration that comes with the torsional twisting of the crankshaft.
As the harmonic balancer or damper gets worn out, you will feel those excessive vibrations which means it will need replacement.
The OEM BMW harmonic balancer is believed to have a poor design which is why it fails prematurely and why many people decide to replace it with an aftermarket part that is actually better than the original.
Engine Mounts Failures
The M57 is a heavy engine and will eventually need replacement engine mounts. Bad engine mounts lead to excessive engine vibrations and other issues so ignoring the issue is not really an option. T
hey are not exactly cheap to replace (approx. 800$).
Turbo Oil Line Leaks
A number of owners are reporting oil leaks coming from the turbo oil supply line. The leak should be addressed immediately to prevent a bigger leak and potential oil starvation of the turbo.
This is one of the most common leaks on the M57 which is not exactly known to have many oil leaks.
Red Boost Hose Fails
All owners of the M57 diesel engine surely know about the infamous red boost hose.
This red boost hose comes with a bad factory upper coupling design. This leads to a boost leak that contains some amount of oily vapors that indicate the position of the leaks as those oily vapors eventually mix up with dirt and show up on the hose.
Replacing the boost hose is the only option and many owners choose one of the aftermarket options with a better design.
NOx Sensor Failures
NOx sensors measure the amount of nitrogen oxide before and after the SCR system to ensure compatibility with the emission standards.
These sensors however are prone to failure and replacing them is not cheap. This is just one more component of the complex SCR system that we mentioned before and many owners despise modern diesel because of this costly system.
Frequently Asked Questions
Is The BMW M57 Engine Reliable?
Yes, in fact, it is one of the most reliable BMW diesel engines ever. The engine alone has very few problems compared to similar engines of other manufacturers. It remains a popular choice amongst used car buyers because of its reliability.
What Is The BMW M57 Operating Temperature?
The correct operating temperature of the M57 diesel engine is between 88-91 degrees celsius. The temperature might rise slightly during a DPF filter regeneration. Anything below 88 degrees can indicate thermostat issues.
The main thing you should be worried about when buying a car with the BMW M57 diesel engine is the state of its emission control components and the intake manifold swirl flaps.
These two components represent the biggest M57 engine problems and a potential risk for expensive repair bills so make sure these two things have had at least some of the components replaced.
Other than that, it is hard to say negative things about the M57. The engine pulls like a train, runs smoothly and the 6-cylinder sound of the engine is incredible, even though it is a diesel.