BMW B58: Everything You Need To Know

BMW’s N55 engine was no doubt one of the best engines ever to hit the automotive market. This under-the-hood legend is an undeniably outstanding craft. Its impact on engine production and design heavily influenced the direction of performance engines.

In their heyday, N55s were casually collecting accolades, winning consecutive awards for their exemplary engine performance. However, just like the old saying goes, good things must come to an end; N55’s retirement became an avenue for BMW to introduce its more refined, more powerful, the N55’s successor, the B58 engine. 

 BMW continues to traverse the streets with their chin held up high as they continue to gather engine awards; winning Wards’ Auto 44 times proves their dominance over the years, which is not easy to accomplish.

In addition to that, B58’s high-output version won Wards’ best engine and propulsion system category in 2020, with its increase of 47 horsepower and 39 lb-ft of torque installed in the M340i. 

What are BMW B58s? 

The award-winning B58 engine is a 3.0-Liter, 328 horsepower, 369 lb-ft, straight-six petrol engine with 82mm bore and 94.6mm stroke; inside, and it is comprised of closed-deck aluminum block, aluminum head, DOHC Valvetronic, and Double Vanos.

BMW began B58’s production in 2015 and was launched in the 2016 340i as a replacement for the N55. B58s also appear in Z4 M40i, X5, M240i, M340i, and Toyota Supras.

Compared to its predecessor, N55, B58s feature a 20% increase in boost pressure due to its closed-deck engine block design; this innovation made a slight addition in displacement from 2979 to 2998 cc.

In colder places, B58s also has a new intercooler design integrated into the intake plenum that is engine-mounted, with a heat encapsulation system that allows the engine to retain some heat up to 36 hours to reduce wear and harmful emissions during start-up.

Engine heat retention is helpful, especially for those who live in colder climates

B58s are part of BMW’s new modular engine family. its new crankcase design imitated the diesel version of B57 that is engineered for gasoline and diesel; these closed-decks are equipped with a completely new structure that can be identified by a complex array of ribs on the exhaust and intake side and an additional reinforcement frame on the oil pump side.

Each engine uses a displacement of 500 cc (30.5 cu in) per cylinder, following the B38 and B48 engine.

Potential Problems for B58 Engines

Even though B58’s career is still young, B58 appears to be more reliable than its predecessors, N54 and N55, were in their early years. Issues such as HPFP and fuel-injector failures were no problems yet for B58s but let us assess some common ones:

Coolant Loss

May it be natural or not, this issue must be tackled and draw some emphasis as the engine grows old after years of usage. Though it is less common, some B58 owners reported that their coolant in the main tank and its secondary tank – for the intercooler, is at a low level.

Without noticeable leaks on the engine, you might want to check your engine for any leaks, or maybe coolant mixed with oil. 

Valve Cover Gasket

As we already know, turbo BMW engine valve cover gaskets are made of rubber. And eventually, these gaskets have been under extreme conditions such as constant heating and cooling cycles that may lead to oil leakage.

These leaks, however, are not premature as they show signs at around 80,000- 110,000 miles. Valves that are made of plastic are more susceptible to leaking and cracking than rubbers. If you notice some burning oil smell, smoke from the valve cover, or light indicators for low engine oil, it may be a leak problem.

Oil Filter Issues

The B58 oil filter does not have much resistance to shear stress. When subjected to shear, its bottom part leaves a portion of the oil filter and remains in the housing. This issue can be solved with your simple hand tools such as pliers, though.

If you are still under warranty, you might want to replace it with a new one. 

VANOS Solenoids

Since it arrived in 1992, BMW’s VANOS system has been the regular maintenance component so far. Though cases are isolated, problems on VAMOS happens heavily on solenoids.

Though they are relatively cheap, replacing solenoids might be a pain for some because of B58’s timing chain location being on the rear of the engine, hard to reach area. That requires some tools.

That might be a challenge, but you don’t have to lift the engine; find the right tools for that.

Modifications and Key Features

The latest version of the B58 has a lot of difference from its debut until the previous release- fuel-efficient, reduced weight, better cooling system, decreased internal friction, and harmful emissions.

It is a progressive engine; after all, its innovations are way more powerful, exciting, and aggressive than its predecessor.

Before, the exhaust manifold and turbo were two separate components. For B58s, those were things of the past already. It features a new single Twin-scroll turbocharger integrated into a compact steel exhaust manifold and impellers for faster response and power.

They weigh less than previous models at approximately around 25%, resulting in significant weight reduction and rapid boost pressure. Fuel is supplied by the new High Precision Injection technology, allowing injection pressures up to 5,076 psi.

The current version of M TwinPower Turbo technology also features VALVETRONIC fully variable valve control and Double VANOS variable camshaft control. It also has a lower compression ratio to offer a tremendous turbo boost. 

The new engine has an improved cooling system; BMW also has done great work to address temperature management in B58s. The B58 engine uses a liquid-to-gas intercooler incorporated into the intake plenum, reducing the volume of air between the turbocharger and the cylinders.

Summary

With the departure of N55, which some will surely miss, B58 is here to stay. Whether it is as good or better than the N55, the new engine deserves a lot of praise. The inexhaustible list of great engines that BMW has is a long one for sure.

And we can’t deny how smooth, effortlessly powerful, and innovative this engine is. Whether you put it on different cars, it does not matter as it will make that car shout. So, put them B58s, spin the wheels, and experience it yourself.