BMW E46 Common Problems: Do you really need a buyer’s guide for a car that is at least 16 years old? We think you do. The E46 3-Series is now an old car by all standards, but it just goes to show how good these cars really were. The E46 is still a valid competitor in terms of looks, road handling and features. Not to mention the amazing inline 6 cylinder petrol engines that are just a dream. In this day and age, they are hard to find these E46, while there are plenty of them out there, those that are worth buying are expensive, and rightfully so. Here are the things you need to look out for and the things that should already be fixed at this age of the car.
BMW E46 common problems after 15+ years
- Before we get into bigger problems, such as the rear subframe issue, let’s talk about some prevention. The E46 3-Series is known for weak rear strut mounts that reveal results in abnormal noises, uneven tire wear, an excessive amount of vibration and even increased wear of shock absorbers. Due to this being a known issue, you can get a rear shock mount reinforcement part that should be fitted when dealing with rear shock mount issues.
- Continuing with one of the biggest E46 faults is the rear subframe mounts. These rear subframe mounting points are a problem on all E46s that have commonly seen snow, salt, and moisture. Cracked or torn subframe mounts can make the car shift while on the move, making it completely unpredictable and unsafe. This should be taken care of in order to prevent further damage to the chassis. This is definitely something you want to be looking at when buying an E46 or an E46 M3. Repairs are not easy and cheap.
- The M54 and M52 6 cylinder engines suffer from the PCV (Positive Crankcase Ventilation) failure and clogging. A clogged crankcase vent valve is recognized by leaky, oil weeping seals of the timing cover, oil pan and the PCV valve cover. This is a result of unreleased pressure and it can lead to serious engine issues. Make sure to check for all and any oil leaks on the 6 cylinder inline petrol engines.
- The double Vanos engines (320i, 325i, 330i) are known for their Vanos issues. The problem lies within the Vanos seals and it results in considerably less torque and uneven power delivery in the lower RPM range (below 3000). This problem can also reveal itself with an unsmooth idle and slightly higher fuel consumption. Replacing these seals is not easy and in doing so, the valve cover needs to come off as well. This is the perfect opportunity to replace that valve cover gasket as well.
- The E46 M3 was also available with a transmission called the SMG or Sequential Manual Gearbox. While these are great to drive, they can be a pain to maintain. One of the problems they had was the failing pump that actuates the gear changes. This is commonly diagnosed with delayed gear changes when using the manual shift paddles on the steering wheel. This repair is pricey which explains why the manual gearbox on the E46 M3 is so sought after.
- When reaching those high mileage numbers (130,000 miles and more), owners report fuel pump failures as one of the things to expect. If your car “runs out of fuel” when there is still clearly fuel in the tank, this can only mean one thing, a faulty fuel pump. Replacing it is not difficult but it can leave you standing by the side of the road.
- Soft engine gaskets are a sure failure point on all vehicles, not just the E46. The E46 however is known for its engine oil filter housing gasket failure. This happens gradually and over time as the gasket hardens. Ignoring this issue can result in big, engine-threatening oil leaks.
- The E46 M3 is an iconic sports car, but it does suffer multiple issues. One of them is the M3 camshaft gear bolt failure. The cam gear bolts are known to break which is why it is recommended to replace the bolt at a 30,000-mile interval. If the bolt breaks while driving, you can expect severe engine damage.
- If you are looking at an AWD E46 model, dubbed the Xi or Xd (for diesel), there is a plethora of drivetrain issues you should be prepared for. The most expensive one is a complete front axle failure. The more common issue however is the torn front axle boots. Both are a pain to replace so do not ignore torn axle boots. Torn boots accumulate dirt and soot which leads to a complete axle failure.
- Another thing you can expect with higher mileage is the worn-out driveshaft flex disc and the center support bearing. You can easily diagnose this if you feel an unpleasant vibration emanating from the driveshaft throughout the car. You can also feel this when releasing the clutch and feeling a clunk of a sort, or sometimes even a delay when suddenly stepping on the gas pedal.
- Many 6-cylinder petrol engines also suffer from faulty hydraulic bucket tappets (HVA) found in the M42, M44, M50, M52, M54, M60, M62, S50, S52 and S62 engines. This causes rattling noises in the valve train area. It might be caused because of unfit oil viscosity, oil level, oil temperature in relation to the outdoor temperature. Resolving these can be tricky which is why most owners do not even bother as the engine can live on for years even if this tapping noise appears once in a while. If you are interested to learn more, read this guide from EngineBuilder.
BMW E46 common problems – Diesel engines
If you are interested in an E46 diesel, here is what you need to be aware of. Generally speaking, the diesel options in the E46 are considered to be reliable when they were kept up and taken care of. Not to mention that the 330d was an exciting option performance-wise.
- The biggest problem of the 330d and the 320d are the plastic swirl flaps of the intake manifold. With years and manifold congestion, these plastic swirl flaps can detach and get sucked into the engine causing havoc on their way. A popular solution is to remove the flaps entirely. Removing them causes very little change in terms of performance but it keeps you free of worries.
- All diesel variants are also known to have problems with clogged EGR valves which can result in a turbocharger failure or even engine failure. Replace this before there is damage.
- 2.0d and 3.0d engines all suffer from common Mass Air Flow sensor failures (MAF).
- Diesel variants of the E46 are also known to have more common rear axle problems. There were reports of them cracking and even braking due to the amount of torque these engines produce.
BMW E46 common problems – Minor faults
- The E46 is known to have plenty of plastic cooling system pieces and reservoirs that are prone to crack as they age. This means you will never be bored when it comes to coolant leaks and failures. Check the car you intend to buy for any coolant leaks! Replacing most of the cooling system parts (water pump, thermostat, expansion tank…) is much cheaper than buying a new aluminum cylinder head which is prone to damage when overheated. Save your engine and don’t save $ on cheap parts.
- Many owners on BMW forums report that it is not uncommon to have power steering fluid loss as these cars reach 150-200k miles. A mechanic should be able to identify the source of the leak and replace the power steering hoses.
- The 6 cylinder inline petrol engines are known to experience occasional ECU (engine Electronic Control Unit) issues. A faulty ECU reveals itself with rough idling, uneven power delivery and “flat spotting”. You can get a used ECU for cheap these days.
- Due to worn-out control arm bushings and control arms themselves, many owners experience a weird jolt feeling on the steering wheel. As we have mentioned before, bushings all across the suspension should be replaced if you are buying a 15+-year-old vehicle. These pieces are made from plastic and rubber so it is only normal for them to deteriorate and wear out.
- Valve cover gaskets and valve covers are one of the most common issues on all E46 models. You identify this problem by seeing oil dripping from the valve cover and smelling burning oil. Replace them as soon as you notice the first signs of trouble!
- Another issue with older vehicles, in general, are the worn bushings. The E46 is known for sub-frame bushing failure. This causes a lot of clunking and banging. Healthy bushings are a big factor for overall suspension health and road handling. Have these replaced when overhauling the suspension, the cost is far lower than the benefits.
- Almost all E46 at this age will need rear springs replaced. Due to salt and moisture, the bottom of the rear spring eventually rusts through and breaks.
- A really simple to fix but a common issue is the failing oil level sensor. A warning light on the dashboard will notify you when the oil level is not sufficient, but in many cases, there is more than enough oil in the engine (according to the dipstick) and the issue lies within a faulty oil level sensor.
Body and interior problems
- As these E46s reach the 10-15-year-old mark, many owners report noise from the top of the front or the rear doors. The noise is caused by worn-out door seals and regardless of all the DIY solutions that the owners come up with, it is best to replace those seals with a new set of OEM BMW door seals.
- Besides some sunroof problems, the interior of the E46 is rock solid, it really stood up to the test of time so there should be no worries here.
- It is important to always clear the airways that allow airflow to the cabin. These are located beneath the windshield. Blocked airways can lead to flooding of the transmission control module.
- E46s BMWs also suffer from common rear light failures which is a thing you will commonly see illuminating the dashboard. The cause for this is either a burned-out rear light bulb or a faulty taillight housing assembly. The replacement circuit board is not expensive and you can easily replace this by yourself.
- If you notice uneven heater fan speeds, regardless of the setting, the common problem is a faulty blower resistor. It is also common that the fan will not turn off when you turn off the ignition or on the other hand, the fan will not start at all.
- While not an expensive problem, it is still a common and annoying one. Failed window regulators are a lengthy repair but they can be done at home with some basic tools as is shown in this forum thread here.
- Some owners also report failing infotainment screens.
- A lot of owners also report common airbag warning lights engaging due to bad connectors.
Frequently asked questions
Is the BMW E46 3 Series a reliable car?
We would definitely say it is. Its biggest problem is age. That is why it is highly important to always seek out vehicles with a clear service history. Most of the common issues with these cars should already be taken care of.
Are BMW E46 going up in value?
Yes. We are seeing this trend in real-time. Just like we saw it happen with his older brother the E36 a couple of years ago. A well-maintained E46, and especially the E46 M3 is definitely going up in value.
BMW E46 common problems: Are BMW E46 parts expensive?
There is no clear answer to this. But generally, we would say no. Especially with all the improved after-market parts and used parts that are available on eBay or scrapyards. Some parts, like the SMG transmission pump, however, remain incredibly expensive.
Are E46 BMWs expensive to maintain?
They are not if you buy a well-kept car. If you buy a car with no service history and no maintenance, then yes, an E46 can be a nightmare.
When was the BMW E46 facelift?
The facelift for the sedan and touring was in 2001 for the 2002 model year, the facelift for the coupe and cabriolet was in 2003 for the 2004 model year. The E46 M3 never received a facelift.
Which BMW E46 engine is best?
All the engines in the E46 chassis are good and comparable. We have covered the issues of all engines here.
Conclusion and recommendation
When it comes to the E46 BMW, one thing is crucial: DO NOT BUY A CAR THAT WAS NOT PROPERLY MAINTAINED. These cars are great, even today if they had their issues sorted. They are so good that many BMW lovers would gladly choose a 6 cylinder E46 over the newer turbo BMW 3 series. If you are in the market for an E46, this might be your last chance. They are going up in value and good examples are harder to find as time goes on. Do it! There are quite a lot of BMW E46 common problems, but regardless, most of these problems are easily fixed if you are caring about your car.
Check out our other buyers’ guides here!