Timm's The BMW M60 M62 and M62TU Engine
Working on the BMW V8 engines - it's not as scary as it first seems
Above is the M60 engine, the first of the modern BMW V8's, it was sold as a 3-Litre (M60B30) and 4-Litre (M60B40)
The M62B44 fitted to the 840ci, the long cable across the front of the engine is for cruise control
The M62TUB44 fitted to the E38 - The CC, ASC and throttle cables have been replaced with EML
History and development M60 BMW introduced the M60 engine in 1992, fitted to the E32 730i and 740i. It was sold alongside the M30 straight-six and the mighty M70 5- Litre V12 in the E32. It was a radical advancement on these engines as both the M30 and M70 were standard 2-valve per cylinder, distributor-ignition engines of traditional design - well, apart from the all electronic throttle control on the V12 and some versions of the M30B35. The M60 engines introduced 4-valves per cylinder, quad overhead cams, coil-over-plug ignition which dispensed with the distributor and HT leads, duplex timing chains, 10.5:1 compression, twin-walled exhaust manifolds and cylinder walls hardened using the Nikasil process rather than using the traditional liner. The new V8 produced more power per litre, but more importantly it was more economical and produced less pollution. The M60B30 was fitted to my first 7 Series and was a good introduction to this great engine, I'm on my 7th BMW V8 now with the N62B46.
Mention the M60 engine, even today in 2016, and the next word will be Nikasil. Nikasil was a process to harden the cylinder walls, rather than using the traditional cylinder liner, the Nikasil process allowed the machined aluminium bores to provide a bearing surface which promised longevity and better sealing between cylinder and piston. Although the Nikasil process had been used previously with no problems, the combination of the M60 and fuels with high Sulphur levels softened the cylinder walls. The resultant wear meant a loss of compression and as the engine was designed without replaceable cylinder liners the engine was effectively scrapped. Although a great many M60's were re-fitted with a new short-block by BMW, these were initially Nikasil blocks and could have failed again. BMW's solution was to replace the Nikasil process with a new cylinder-hardening process called Alusil. Around the same period, the Sulphur levels in fuels was reduced and those engines that suffered bore wear were replaced, and those that were not replaced were not affected once the Sulphur levels decreased. As Nikasil deterioration resulted in catastrophic engine problems due to bore failure there were no engines that were affected but kept running for any length of time, and this meant that the Nikasil failure period was limited. It has been many years now since Nikasil failure was a worry with the M60 engine - further details can be found here. It might have been expected that the 730i V8 (218 BHP) would have much better performance than the 730i I-6 (185 BHP), and the M30 engined E32 would be dropped - but this was not the case as BMW fitted the V8 models with a 3.23 differential whereas the I-6 730i got the much shorter 4.1. The result was that the V8 had the same 0-60 MPH performance as the I-6 and most owners of the 730i were not that interested that the V8 was 5 MPG more frugal.
M62 If the M60 had a shortcoming it was the lack of torque at low revs, especially the 3 Litre M60B30 which really only got going at 4000 RPM. The long final drive ratio certainly didn't help, especially since the part-throttle gear-changes were made well below the power-band. To address the lack of performance at low revs the M62 was introduced in 1995.
The M62 was produced as the 3.5 Litre M62B35 and the 4.4 Litre M62B44 and fitted to the E31 and E38. The published power for the 4.4 Litre M62 was 286 BHP (sometimes quoted as 282 BHP) which is the same figure as quoted for the 4 Litre M60. Again, BMW changed the differential from 3.15 to 2.93 when the M62 was introduced (except for the Sport 740i which retained the 3.15) and the acceleration figures again remained the same. The same differential ratio change was present on the 8-Series 840ci. When the M62 was introduced in the E31, the rear axle ratio changed from 2.93 (M60) to 2.81 (M62) - and still the same acceleration figures were stated. Mechanically the M62 lost a couple of useful parts, the duplex timing chains and the idler sprocket, in their place was added a single timing chain and plastic chain guides. In performance terms, the M62 produced a hefty amount of torque at lower revs and the more sophisticated DME 5.2 engine management increased fuel economy. However, the improvements didn't really make that much difference, especially with the longer final drive, and it wasn't until the M62TUB was introduced that the performance targets were realised. The DME 5.2 engine management added a lot tighter control of the engine and the diagnostic capabilities were increased drastically.
M62TUB The M62TUB44 is really the engine that the M60 aspired to be, it has heaps of low-down torque, is economical and produces much lower emissions. The main difference was the introduction of variable valve timing on the inlet camshafts (Vanos), this was the source of the flatter torque-curve and the better fuel economy.
The M62TUB also introduced fully-electronic throttle control (EML), this meant that the ASC and cruise-control actuators were not required, but more importantly, it meant that the throttle response could be altered depending on driving style. The relation between throttle pedal and throttle butterfly were not fixed as it is when a cable is used, instead the throttle butterfly could open by different amounts and at different speeds with the same pedal press depending on driving mode. This gives the 740i and 540i with the M62TUB44 better performance at all engine speeds. Perversely, the published acceleration remained the same as did the BHP, owners who have driven both versions would disagree. The added complexity also increased the problems with the V8 with the introduction of 'Vanos noise' (which wasn't terminal although annoying) and failure of the timing solenoids and seals. Engine details: More information on all three versions of the V8 can be found below: M60 M62 M62TUB Problems with the modern V8: The M60/M62/M62TUB engines have proved exceptionally reliable - there are many thousands of the Nikasil M60's still in daily use, maintaining perfect compression. After a shaky start the modern BMW V8's have proved to be an unrivalled success. However, they have a few weak spots, the most common are listed below: The cooling system overheats and explodes The crankcase ventilation system causes all sorts of problems The valve train makes some scary noises The M62TUB44 can suffer from 'Engine Failsafe' problems The M60 could easily over-fuel and fail to start for days Vacuum leaks causes strange behaviour Click on the links below for more information and repair instructions:
Timm's The BMW M60 M62 and M62TU Engine
Working on the BMW V8 engines - it's not as scary as it first seems
Above is the M60 engine, the first of the modern BMW V8's, it was sold as a 3-Litre (M60B30) and 4-Litre (M60B40)
The M62B44 fitted to the 840ci, the long cable across the front of the engine is for cruise control
The M62TUB44 fitted to the E38 - The CC, ASC and throttle cables have been replaced with EML
History and development M60 BMW introduced the M60 engine in 1992, fitted to the E32 730i and 740i. It was sold alongside the M30 straight-six and the mighty M70 5-Litre V12 in the E32. It was a radical advancement on these engines as both the M30 and M70 were standard 2-valve per cylinder, distributor-ignition engines of traditional design - well, apart from the all electronic throttle control on the V12 and some versions of the M30B35. The M60 engines introduced 4-valves per cylinder, quad overhead cams, coil-over-plug ignition which dispensed with the distributor and HT leads, duplex timing chains, 10.5:1 compression, twin-walled exhaust manifolds and cylinder walls hardened using the Nikasil process rather than using the traditional liner. The new V8 produced more power per litre, but more importantly it was more economical and produced less pollution. The M60B30 was fitted to my first 7 Series and was a good introduction to this great engine, I'm on my 7th BMW V8 now with the N62B46.
Mention the M60 engine, even today in 2016, and the next word will be Nikasil. Nikasil was a process to harden the cylinder walls, rather than using the traditional cylinder liner, the Nikasil process allowed the machined aluminium bores to provide a bearing surface which promised longevity and better sealing between cylinder and piston. Although the Nikasil process had been used previously with no problems, the combination of the M60 and fuels with high Sulphur levels softened the cylinder walls. The resultant wear meant a loss of compression and as the engine was designed without replaceable cylinder liners the engine was effectively scrapped. Although a great many M60's were re-fitted with a new short-block by BMW, these were initially Nikasil blocks and could have failed again. BMW's solution was to replace the Nikasil process with a new cylinder-hardening process called Alusil. Around the same period, the Sulphur levels in fuels was reduced and those engines that suffered bore wear were replaced, and those that were not replaced were not affected once the Sulphur levels decreased. As Nikasil deterioration resulted in catastrophic engine problems due to bore failure there were no engines that were affected but kept running for any length of time, and this meant that the Nikasil failure period was limited. It has been many years now since Nikasil failure was a worry with the M60 engine - further details can be found here. It might have been expected that the 730i V8 (218 BHP) would have much better performance than the 730i I-6 (185 BHP), and the M30 engined E32 would be dropped - but this was not the case as BMW fitted the V8 models with a 3.23 differential whereas the I-6 730i got the much shorter 4.1. The result was that the V8 had the same 0-60 MPH performance as the I-6 and most owners of the 730i were not that interested that the V8 was 5 MPG more frugal.
M62 If the M60 had a shortcoming it was the lack of torque at low revs, especially the 3 Litre M60B30 which really only got going at 4000 RPM. The long final drive ratio certainly didn't help, especially since the part-throttle gear-changes were made well below the power-band. To address the lack of performance at low revs the M62 was introduced in 1995.
The M62 was produced as the 3.5 Litre M62B35 and the 4.4 Litre M62B44 and fitted to the E31 and E38. The published power for the 4.4 Litre M62 was 286 BHP (sometimes quoted as 282 BHP) which is the same figure as quoted for the 4 Litre M60. Again, BMW changed the differential from 3.15 to 2.93 when the M62 was introduced (except for the Sport 740i which retained the 3.15) and the acceleration figures again remained the same. The same differential ratio change was present on the 8-Series 840ci. When the M62 was introduced in the E31, the rear axle ratio changed from 2.93 (M60) to 2.81 (M62) - and still the same acceleration figures were stated. Mechanically the M62 lost a couple of useful parts, the duplex timing chains and the idler sprocket, in their place was added a single timing chain and plastic chain guides. In performance terms, the M62 produced a hefty amount of torque at lower revs and the more sophisticated DME 5.2 engine management increased fuel economy. However, the improvements didn't really make that much difference, especially with the longer final drive, and it wasn't until the M62TUB was introduced that the performance targets were realised. The DME 5.2 engine management added a lot tighter control of the engine and the diagnostic capabilities were increased drastically.
M62TUB The M62TUB44 is really the engine that the M60 aspired to be, it has heaps of low-down torque, is economical and produces much lower emissions. The main difference was the introduction of variable valve timing on the inlet camshafts (Vanos), this was the source of the flatter torque-curve and the better fuel economy.
The M62TUB also introduced fully-electronic throttle control (EML), this meant that the ASC and cruise-control actuators were not required, but more importantly, it meant that the throttle response could be altered depending on driving style. The relation between throttle pedal and throttle butterfly were not fixed as it is when a cable is used, instead the throttle butterfly could open by different amounts and at different speeds with the same pedal press depending on driving mode. This gives the 740i and 540i with the M62TUB44 better performance at all engine speeds. Perversely, the published acceleration remained the same as did the BHP, owners who have driven both versions would disagree. The added complexity also increased the problems with the V8 with the introduction of 'Vanos noise' (which wasn't terminal although annoying) and failure of the timing solenoids and seals. Engine details: More information on all three versions of the V8 can be found below: M60 M62 M62TUB Problems with the modern V8: The M60/M62/M62TUB engines have proved exceptionally reliable - there are many thousands of the Nikasil M60's still in daily use, maintaining perfect compression. After a shaky start the modern BMW V8's have proved to be an unrivalled success. However, they have a few weak spots, the most common are listed below: The cooling system overheats and explodes The crankcase ventilation system causes all sorts of problems The valve train makes some scary noises The M62TUB44 can suffer from 'Engine Failsafe' problems The M60 could easily over-fuel and fail to start for days Vacuum leaks causes strange behaviour Click on the links below for more information and repair instructions: