Nearly a decade and a half ago, BMW introduced the N63 — their first twin-turbo V8 engine ever, and it powered some of the larger models in the BMW portfolio. Anything from the 5-Series to the X7 featured this iconic engine.
A little more than three years after the N63 debuted, BMW would reveal a high-performance iteration of the engine called the S63. The S63 is the epitome of BMW’s performance engines and, perhaps, one of the most capable units in its segment.
The S63 has been around for over a decade now, and BMW has made some significant updates to ensure that the ones we get to experience today are a lot more reliable than they once were.
Here’s all you need to know about the BMW S63, from the technology it features to the cars it powers and the problems you might potentially face as an owner.
Technology Behind The BMW S63 Engine
The BMW S63 has a lot in common with the standard N63 engine it’s based on. The latter debuted the revolutionary “hot-vee” layout on a production V8 engine. For the uninitiated, this is an engine design where the turbocharger is placed in between the valley created by the cylinders. Doing so puts the exhaust manifolds between the cylinder banks and the intake manifolds on the outside — unlike on a conventional V-engine where it’s the other way around.
A hot-vee layout allows for a more tightly packed engine bay layout and takes up significantly less space than a typical turbocharger setup. It also reduces the distance that air has to travel from the exhaust to the turbochargers, improving spool time and cooling. Speaking of, the S63 features two twin-scroll turbochargers. It also came with a pulse-tuned, cross-engine exhaust manifold. This enabled a constant exhaust airflow to the turbos with every 180-degree rotation.
When the S63 debuted, it didn’t come with BMW’s Valvetronic or variable valve lift technology for the first few years. It was introduced shortly after with the first ‘Technical Update’ along with other notable mechanical changes.
BMW S63: Available Versions
Courtesy of the mechanical masterminds at the M Division, the S63 is the most potent engine ever fitted onto a production BMW. Its most recent avatar produces a staggering 635 hp and 553 lb-ft of torque at the heart of the new BMW M5 CS — the most powerful production BMW ever.
However, when the S63 debuted in 2011, it produced nearly 100hp less in the X5 M (E70) and X6 M (E71). The German manufacturer has made some major strides in its development, with four engine versions being produced over the last decade.
S63B44O0
The S63B44O0 is the original S63 engine. When it was introduced in 2011, it produced 547 hp at 6,000 rpm and 502 lb-ft of torque at 1,500-5,650 rpm.
BMW stopped manufacturing the engine in 2013.
S63B44T0
A year after the S63B44O0 debuted, BMW released the S63B44T0, or the engine’s first ‘Technical Update’. This was one of the more significant updates in the history of the S63 engine as it introduced the Valvetronic tech and a higher compression ratio (up from 9.3:1 to 10:1). The update also saw the rev limit rise from 6,800 rpm to 7,200 rpm — a redline still part of today’s S63 engines.
Despite the notable mechanical updates, peak output figures, on paper, are pretty close to the pre-update engine with 553 hp at 6,000-7,000 rpm and 502 lb-ft of torque at 1,500-5,750 rpm.
The S63B44T0 was in production until 2018.
S63B44T2
The S63B44T2 was produced from 2015 to 2018, with peak figures of 567 hp at 6,000-6,500 rpm and 553 lb-ft of torque at 2,200-5,000 rpm.
S63B44T4
The S63B44T4 is the most recent form of the S63 engine and is still in production today. The engine is available in multiple tunes depending on the car it’s being used on.
Peak power ranges from 591 hp at 5,600-6,700 rpm to 635 hp at 6,000 rpm, while peak torque remains a neck-snapping 553 lb-ft on all iterations.
Which BMW Cars Have The BMW S63 Engine?
The S63, considering its prowess, has only made its way onto the upper range of the M models in BMW’s extensive lineup. This includes the X5 M, X6 M, M5, M6, and the M8.
S63B44O0
The only BMW cars that the S63B44O0 powered were the X5 M (E70) from 2010 to 2013 and the X6 M (E71) from 2010 to 2013. The engine was also used in the Wiesman GT MF5 from 2011 to 2014.
S63B44T0
The S63B44T0 made its debut on the F10 5-series M5 and would then power M6 models at the time.
- 2011–2017 BMW M5 (F10)
- 2012–2018 BMW M6 (F12/13)
- 2013–2018 BMW M6 Gran Coupé (F06)
S63B44T2
The S63B44T2 was the successor to the S63B44O0 and powered only the X5 M (F85) and the X6 M (F86) from 2015 to 2019.
S63B44T4
The S63B44T4 is the most extensively used version of the S63 engine. The list of BMW cars it powers includes:
- 2018–present M5 (F90)
- 2018–present M5 Competition (F90)
- 2019–present M8 (F91/92/93)
- 2019–present M8 Competition (F91/92/93)
- 2020–present X5 M (F95)
- 2020–present X5 M Competition (F95)
- 2020–present X6 M (F96)
- 2020–present X6 M Competition (F96)
How Much HP Can the S63 Handle?
With relatively straightforward updates like an ECU tune and a performance exhaust, the S63 can produce upwards of 750hp. The 4.4L V8, even in stock form, makes a mind-boggling 635 hp and 553 lb-ft of torque.
The stock turbochargers can handle about 25-26psi of boost, beyond which you’ll have to splurge on some aftermarket, high-performance units.
More complex changes like performance crank and pistons, aggressive cam profiles, and high flow injectors can take power figures upwards of 800 hp, but such tunes can be highly demanding of the engine. There are multiple reports that heavily modded S63 engines have failed because the rod bearings could not handle the power.
Is the BMW S63 Engine Reliable?
The S63 has been around for just over a decade now, and BMW has made some significant updates to it during that time. While earlier iterations of the S63 were somewhat unreliable, BMW has ironed out most of its faults with the versions that followed. Nevertheless, since this is a high-performance engine with a history of mechanical faults, it’s better to be wary of some of the problems you might encounter with an S63:
Rod Bearing Problems
One of the issues that tend to make most potential owners cautious about investing in an S63 are the rod bearings. You’ll find multiple posts on forums asking if this is something to be worried about and even a few reporting the issue.
The BMW S range of engines — S54, S65, and S85 — have all had reports of faulty rod bearings. However, this issue is nowhere near as common as you might think. On a well-maintained engine, the rod bearings shouldn’t wear out prematurely. On the flip side, if an engine suffered oil starvation at some point, you could expect issues.
It’s worth noting that even owners who’ve maintained their engine immaculately have faced bearing failures. However, this is extremely rare.
Unfortunately, a rod-bearing failure can have catastrophic consequences and will most likely result in a knocking engine. As the bearings start to wear out, they will damage the crankshaft and affect the movement of the pistons. The resulting phenomenon is called rod knock since it’s a deep tapping sound from within the engine.
Failing rod bearings can result in pretty easy-to-spot symptoms, like copper shavings in engine oil and the knocking sound we mentioned above. Fixing a rod bearing issue will easily set you back a few thousand dollars, so we hope it’s something you never have to deal with.
Excess Oil Consumption
Earlier versions of the standard N63 consumed abnormal amounts of oil, and this is something you should be wary of if you’re buying an older BMW S63 engine. A turbocharged engine usually consumes more oil than a comparable naturally-aspirated unit because the oil needs to lubricate and cool the turbos. However, the oil levels that the original N63 consumed were far from ordinary.
There were several reasons why the engine used up so much motor oil. The more notable ones include failure of the piston rings, turbocharger oil seals, crankcase vent hose leaks, or a cracked valve stem seal. BMW acknowledged this was a problem on the standard N63 and introduced redesigned valve guides with tighter clearances, and replaced the affected part for free.
As we mentioned, this was a problem with the standard N63, and BMW did resolve it shortly after it was detected. It’s unlikely that you’ll face similar issues with the S63, but if oil consumption seems unnatural, you should get the engine checked.
VANOS Solenoids Problem
VANOS is BMW’s denomination for variable valve timing technology. The S63 features double VANOS or adjustment of the timing on the intake and exhaust valves. While this is a technology that has been around for a while, the system on the BMW involves some parts that have shown a history of premature failure. The most susceptible of these parts is the VANOS solenoids.
The solenoids actuate the position of the cams, and they are constantly at work while the engine is running. Understandably, they will show signs of wear over time. The problem is when they start to fail sooner than expected. The solenoids should easily last over 100,000 miles on a well-maintained and run engine.
The solenoids are not very expensive, but the BMW S63 features four of them, so the cost can add up to a bit if multiple are affected. A faulty solenoid should translate to rough idling, stuttering, and a drop in performance. It might also send your engine into limp mode in more severe cases.
Ignition Coil Failure
Like the VANOS solenoids, the ignition coils are another component that is more likely to fail due to poor maintenance rather than a manufacturing defect. You’ll have to ensure the coils are in good condition a lot more often than you would have to on most other vehicles — high-performance, turbocharged engines can be pretty tough on the ignition system.
If one ignition coil fails, the rest of them are bound to follow suit shortly after. Ignition coil failures will result in symptoms similar to what you’d experience with a VANOS solenoid failure — engine misfiring and stuttering, shaky idling, and sudden drops in power.
Maintaining a BMW S63 Engine
A high-performance engine will always require more care than a regular one. While mechanical problems are not inevitable, properly maintaining your engine will help keep them at bay for as long as possible. Servicing the engine on time and using quality parts is fundamental if you want to experience the performance an S63 was engineered to deliver.
At Bimmers.com, we offer a wide range of genuine BMW, OEM, and quality aftermarket parts for any BMW. To find the best part for your car, head over to our shop section, select your vehicle from the drop-down menu, and search for the part you need.
