BMW B58 Common problems
Since 2015, the BMW B58 engine has been one of the most revered tuning platforms in new cars. As the successor to the mighty N55, the B58 retains much of what made the N54 and N55 engines so great, while being updated with higher feed pressure, greater displacement and increased compression ratio.
First seen in the 2016 340i, the B58 earned a reputation as an engine brimming with tuning potential and solid reliability.
The B58 has seen its fair share of use in models such as the 340i, 440i, M340i, X4 M40i and even the new generation Toyota Supra, among many others. The consensus is that the B58 holds its own in terms of reliability, even compared to its Japanese and American counterparts.
Differences in the B58
Not all B58s are created equal. The biggest change came in 2019 with the release of the B58TU1. The TU1 update introduced changes such as a revised timing chain, fuel system, cylinder heads and other minor updates.
The TU1 sees a slight power bump over the original. BMW introduced the update with emissions in mind, so many of the changes are aimed at improving fuel economy due to the EU’s emissions crackdown.
Being such a new platform, the TU1 doesn’t yet have much of a history in terms of reliability, but one would assume that BMW’s changes could only mean better reliability compared to previous models as they had the opportunity to iron out some known problems .
That said, some of these common issues could also apply to the TU1, so owners and potential buyers should still be on the lookout for them.
Common B58 problems
VANOS solenoid
VANOS is BMW’s proprietary system for dynamic valve timing, similar to the well-known Honda VTEC or Toyota’s VVT-i. With VANOS specifically, the timing is controlled by changes in oil pressure, which are caused by a tightly wound coil called a solenoid. Reoccurring in many BMW engines, the VANOS solenoid also affects B58 owners.
The most common cause of VANOS problems on the B58 (and many other BMW engines) is a failed solenoid o-ring. Over time, the rubber O-ring degrades due to wear and high temperatures. This failure allows the oil to leak and alter the ability to actuate the VANOS solenoid.
In other cases, the solenoid can become clogged with oil contaminants. Dirt, metal shavings and old oil can prevent the solenoid from working properly.
Both problems usually cause similar symptoms. Loss of power, sluggish throttle response, decreased efficiency, limp mode, and a rough idle are just some of the problems that can arise as a result of VANOS problems.
Since you cannot see VANOS failure, the only true way to prevent it is through proactive maintenance. BMW recommends replacing the VANOS seals every 50,000 miles and even a complete system replacement at 70,000 miles.
Valve cover gasket
Another mainstay in BMW’s “common problems” category is the valve cover gasket (VCG). This is not exclusive to BMWs per se, as any modern car will come with a rubber VCG that degrades with use.
However, BMW VCGs seem to have a knack for failing. Between 60,000 and 100,000 miles, owners should be on the lookout for leaks around this area, as oil loss can cause major headaches if left untreated.
Be on the lookout for symptoms such as a burnt oil smell, soaked spark plugs, low oil light and visible gasket leaks.
However, it’s not as if BMW turned a blind eye after its previous models. One of the main causes of rubber gasket wear is the extreme heat cycles the engine experiences. The transition from cold to hot, and vice versa, repeatedly is the main source of engine wear in general.
The B58 is BMW’s attempt to solve the problem. The B58’s heat retention system is said to maintain engine temperature for up to 36 hours, allowing for a more gradual heat cycling process and less temperature shock for sensitive parts like the VCG.
Disintegration of the oil filter
“Disintegration” is not a word you want to hear in most situations when talking about a car.
However, it is simply the best way to describe this problem. The B58 (and other BMW engines, for that matter) have a strange habit of tearing their oil filters to pieces from normal use.
As the oil passes through, the filter eventually begins to pull away from the housing and eventually breaks into several pieces.
Oil filters, even those made by BMW, are not expensive. That’s not necessarily the issue here, though. The oil filter can’t do its job if it’s not intact, so this allows foreign particles and contaminants to get into places they shouldn’t.
These metal particles, dirt, etc., can cause rapid corrosion in the engine and eventually costly problems.
The problem is best avoided with proper oil and filter change intervals. Not exceeding the recommended range is important anyway, but it also gives less opportunity for wear and tear to break the filter.
Excessive coolant consumption
In a perfect world, engines are designed and assembled with such precision that fluid loss is essentially eliminated. In the real world, however, engines have flaws. Coolant can leak or burn in certain areas of the engine, but usually at a slow rate that doesn’t cause much of a problem.
Then there is the B58. Although a specific cause has not been identified, many B58 owners report a faster than usual loss of coolant, even on lower mileage engines. Some have attributed this to faulty coolant reservoir caps or seals around the cooling system.
In the end, a slight loss of coolant is nothing to worry about. Whenever and wherever you need it, you don’t have to do much. It’s something that all B58 owners should be aware of, especially those who don’t move under the hood too much, as it can be easy to miss when they’re not looking.
However, if you don’t top off the coolant, the car may start to overheat. In severe cases, this can cause catastrophic engine damage.
Since it appears to be a minor factory defect or just an expected loss of coolant, there isn’t much you can do to prevent it. However, it is always recommended to check the seals and coolant cap, as any visible leaks can mean much worse for your vehicle than the gradual loss of coolant.
Is the B58 a reliable engine?
No engine is perfect. Despite the improved reliability over its older siblings, the B58 still has some common issues that you should be aware of if you own or want to buy a B58-powered car.
However, if you want to compare it apples-to-apples with other engines, the B58 remains a solid platform that will run for a long time with proper maintenance. As far as Euro cars go, there’s perhaps no platform as tuner-ready yet daily-driveable as the B58.
The B58s are also worth it
If you’re looking for a rig ripe for some screws and a tune, while still managing to maintain composure with more boost and a hard ride, the B58 might be a good choice.
Any engine, German or not, can and will have faults. The B58 has some problems that have been present in BMW engines for several generations, so the causes, symptoms and solutions are well documented and readily available.
Most of these problems can be prevented with a little forethought and a small investment in preventative maintenance. While apparently expensive (it’s still a Bimmer), being proactive can save you thousands down the road.
Service B58 at Alex’s Autohaus
If you own a car with a B58 engine, trust your maintenance to Alex’s Autohaus in Midvale, Utah. Our European engine specialists have seen it all and know how to service engines as special as the B58 to the highest quality.
Call or schedule an appointment online today to secure your spot with the premier Euros service center in the Salt Lake Valley!
