The BMW M3 has been a very popular performance coupe ever since the German automaker introduced the first generation in 1986.
Now in its sixth generation of production, the M3 remains a very popular vehicle.
Several mechanical issues have arisen over the years, many of which are detailed below.
1. Bad Radiator Overheats Engines and Enrages Owners
Radiators help to cool the engine by providing some airflow that cools the circulating engine coolant.
The BMW radiators have a bad reputation for plugging up or otherwise failing to circulate the coolant properly.
When the engine does not get the intended cooling effect, they heat up and wear out much faster than designed.
Heat increases friction, which in turn creates more heat. Sooner or later, the engine fails and needs costly repairs or possibly a complete replacement.
If your BMW M3 is overheating, the radiator is the likely cause. Fortunately, even a BMW radiator is relatively inexpensive and easy to replace compared to the cost of repairing or replacing the entire motor or searching for a new vehicle.
You should pay close attention to the engine temperature gauge to see if it is running hot. If so, you should check the radiator for any problems and be prepared to replace it.
Otherwise, you should flush and fill the coolant about once per year to help ensure the radiator is working well and to keep the coolant in optimal condition.
2. Faulty Valve Timing Leaves Drivers Stranded
Engine valves let air in and exhaust out of the combustion chamber. Timing is critically important to ensure the valves work as designed.
Therein lies a critical problem with the valve timing on many B3 motors.
BMW’s VANOS unit is supposed to provide perfect timing for the valves. The VANOS unit is designed to advance and retard the valve timing based on engine RPMs. The idea is to provide drivers with the best engine performance and fuel economy.
The VANOS unit has seals that wear out quickly, which causes it to wear out quickly.
A worn-out VANOS unit will not operate the valves properly and greatly affects engine performance.
Replacing the unit is the only solution, but BMW has a bad habit of using the same defective seals when it replaces a faulty VANOS unit.
Luckily, the unit tends to wear out while the manufacturer’s warranty still is in effect.
But using the same bad seals just makes owners relive the bad experience. Because of the seals, the VANOS unit often has a service life of about 20,000 miles. Using aftermarket seals could solve the problem and extend the unit’s service life to more acceptable levels.
3. Excessive Oil Consumption Endangers Motors
All internal combustion engines need good oil to reduce friction and internal heat. When an engine consumes oil at an excessive rate, the oil cannot do its job as intended.
Driving on low oil will cause the engine to run hot, might warp the heads, and could result in costly internal damage.
If your M3 is consuming a lot of oil, a common culprit is the crankcase ventilation valve (CVV).
The valve sometimes has a bad seal that will enable oil to leak. The leaking oil often winds up on the external part of the engine, which makes it harder to detect.
Paying close attention to the oil level and topping it off whenever it is about a pint low will help to protect your engine.
Your BMW dealership or a qualified mechanic can check the CVV unit and replace it if it is letting oil leak past its seal.
The head gasket also is a potential cause of excessive oil consumption. If your M3 has developed a bad gasket, it could allow oil to seep out of the engine. A compression check can help to determine whether or not you have a bad head gasket.
If so, a replacement is needed and might be covered by the manufacturer’s warranty.
4. Transmission Shifts Into Neutral While Driving
The M3’s transmission has a very bad habit of shifting out of gear while being driven.
That is not to say that all M3s do that, but enough have to affirm that a definite problem exists.
The fortunate part is that shifting into neutral does not damage the engine or transmission like it would if it were shifting into reverse, park, or a very low gear from a high one.
It never is good to have a transmission that drops out of gear. Fortunately, you generally can shift back into gear, but the problem still is a major annoyance and might reduce the service life of your BMW’s transmission.
You should pay close attention to the transmission fluid levels to help ensure it has plenty to operate as intended.
If your M3 transmission insists on switching to neutral while you are driving, the fix often is to replace it.
That is neither affordable nor practical, but it might be the only permanent solution. If the problem persists, though, you wasted money on the new transmission.
Many owners have found it necessary to buy an entirely new car or a different model to get rid of the transmission problem – along with the M3.
5. Bushings and Mounts Wear Out and Rattle Your Cage
Engine mounts keep motors secured to the chassis while bushings help the suspension and other mechanical components to remain secure and silent.
Unfortunately, the engine mounts and bushings in the M3 tend to wear out quickly, which creates a lot of noise and unsettling rattling sounds while you are driving.
You should have a qualified mechanic closely inspect the engine mounts and various seals the make sure they are in good condition.
If any signs of cracking or premature wear and tear are found, your mechanic should replace them right away.
Immediate replacement of worn bushings or seals will help your BMW to stay in good condition throughout your ownership.
6. Interior Noises Also Annoy Passengers
Few things can be more annoying than buying a high-dollar luxury model like the M3 and having to put up with annoying sounds coming from the interior. A quiet cabin is a comfortable one.
No matter how comfortable the M3’s interior is built to be, many models have annoyed their owners with unwanted sounds that make the drive less pleasurable.
If you like to listen to loud music while driving, that could cure the rattles, squeaks, and other annoying interior sounds that many M3 owners have complained about.
A more practical solution is to keep the interior as clean as possible and use leather conditioners and similar products to keep upholstery, dash, and seats in their best condition.
7. Fuel Delivery Problems Affect Engine Performance
Several M3 owners have complained about poorly running engines due to a variety of potential fuel delivery issues.
When fuel does not reach the combustion chamber in the correct amounts, the engine could run lean, and a lean-running engine might damage the valves and create a hot-running motor.
The most serious problem could be a faulty fuel pump that could fail without much warning.
If you are driving and the motor starts to hesitate and misfire, it might be a fuel pump that is going bad.
A clogged fuel filter could create similar problems, but that is unlikely if your M3 has low miles on the odometer.
Replacing the fuel pump with a new one should correct the problem. If your M3 is under warranty from BMW, the manufacturer’s warranty should cover the cost to replace it. Hopefully, that problem will not arise again.
It also is possible for the fuel injectors to malfunction and deliver improper amounts of fuel to the combustion chamber.
Bad fuel injectors will act like a bad fuel pump and cause similar problems.
Close inspection and yearly service of the fuel injectors should help to keep them in good condition and identify any potential problems before they become too serious.
8. Rough Idle Due to Faulty Idle Control Valve
The idle control valve helps to keep the M3’s engine running smoothly while stopped. It also helps to deliver the best fuel economy by adjusting the engine’s fuel consumption during stops and starts while driving in city traffic.
A faulty idle control valve can make the M3 run roughly and possibly stall while you are stopped at a light or going through a drive-through restaurant or some other establishment.
A roughly running motor will make your fuel economy drop and raise your ownership costs until you address the problem.
The solution is to replace the faulty idle control valve.
A new one will help to restore your M3’s smooth idling and improve the fuel economy. The fix can pay for itself when compared to the cost of continuing to drive with a faulty idle control valve.
General Pros and Cons of the BMW M3
A well-maintained M3 is stylish and very fun to drive.
You can get the true sportscar-like driving pleasure that you also could use as a daily driver.
The M3 works equally well as a performance platform with a stout straight-six engine with twin turbochargers that deliver plentiful power.
You get up to 503 horsepower from the competition edition and 473 horsepower in the standard version.
The rear-wheel drive M3 makes a great rally car and works well on track days, but you have to pay more to get one with a six-speed manual transmission.
The price is high for a new model, but well-maintained used ones are more affordable and can provide you with an exceptionally comfortable and sporty ride.
What Do the Reviews Say?
The M3 delivers a smooth ride with lots of performance potential. It is quick, fast, and provides passengers with a comfortable ride thanks to a high-end interior.
The fuel economy is decent at up to 23 mpg per gallon, but that is pretty good for a sporty car that also works great as a daily commuter.
You can choose a standard model that offers a manual transmission. But the faster and more potent competition model only gives you the choice of a six- or eight-speed automatic.
An automatic will work just fine for most people, but rally racers will have to choose the less powerful standard version and modify the performance potential if they want to race.
What’s the Resale Value on the BMW M3?
Like any high-priced luxury sedan, the M3 loses a significant amount of value during its first five years of ownership. The value drops by 38 percent by the time the car is five years old.
A 10-year-old model will have depreciated by nearly two-thirds of its retail cost.
The depreciation is understandable and acceptable for those who can afford new models. After all, if you can lay out more than $70,000 for a new car, depreciation likely is the least of your concerns.
Finding an older model in good condition could deliver a fine ride with good performance at about a third of the new car’s cost.
Those who are looking for a reasonably good value in a performance sedan would do well to search out models that have been well-maintained and have relatively few miles on the odometer.
Knowing the common problems that afflict the vehicle will help you to find the best used car value.
You should find models that have excellent maintenance records and have undergone any manufacturer recalls that apply to them.
Some due diligence can help you to find a great value in a very potent BMW M3.