BMW S62 V8 M-Tech Engines

BMW S62 engine

The S62 in all it's glory.

Chronology

The previous E34 M5 was a superb car, in it's final form the 3.8 litre S38 pushed out 341bhp and did it in fabulous style. But the S38 was by now an old engine whose roots went back to the late 1960s. For the new E39 M5 something altogether new was needed.

BMW had the M62 V8, a modern engine which at the time went up to 4.4 litres (the 4.6 and 4.8 came later). This would form the basis for the new 4941cc S62.

In 1998, some years after the rest of the E39 range, the new M5 was launched to a rapturous reception. This five litre V8 revved to 7000rpm, not normal V8 behavior at all. It sold in droves.

When the Z8 roadster was launched the following year the S62 was the only factory option (although Alpina offered an automatic with a modified 4.8 M62).

BMW stopped using the S62 in 2003 when the E60 five series replaced the E39 but it was used by Ascari in their own supercars for some time after.

Now that's some air box!

Design

Unusually the S62 didn't make major structural changes to it's M62 parent in the way that was often required. This may say a lot about how good the M62 was. These similarities meant that the S62 could be made on the normal Dingolfing production line rather than at the Motorsport plant in Garching as had always been the case before.

Undoubtedly the largest modifications were to the intake system, this had eight individual throttle bodies where were electronically activated. The driver could select normal or sport mode to map the throttle body response to the accelerator pedal. Above the throttle bodies was a snakes next of intake trumpets designed to provide just the right lengths and pressures. The massive air box was fed by twin MAFs and the exhaust was a lightweight design with high flow cats.

This was the first M-Tech engine to have hydraulic self adjusting tappets, rather a boost as there were 32 of them. To ensure good oil pressure even under high cornering forces scavenger pumps were fitted but only activated when needed.

Unlike the single VANOS M62TU the S62 used VANOS on all four of its hollow camshafts. To provide durability even at the 7000rpm rev limit the timing chains were double row.

The crank and conrods were made by forging and then balanced. An 11:1 compression ratio was used and this required a special steel head gasket. The only way to supply enough fuel was to run the fuel system at 5 bar (70psi) instead of BMW's more normal 3 bar pressure.

This was certainly an M62 that had eaten it's porridge!

BMW S62 engine

E39 M5 with an S62.

Variants

Code Size Power
bhp@rpm		 Torque
lb/ft@rpm		 BHP/
litre		 Torque/
litre		 Made Bore x
Stroke		 Timing Weight
(kg)		 VANOS Used in
S62 4.9 400 @ 6600 369 @ 3800 81.6 75.3 98 - 2003 94x89 Chain 158 Dual E39 M5, Z8

 

BMW S62 engine

S62 in a Z8.

Problems

The VANOS seals suffer a similar fate to those on S50B32 and S54 engines, they become hard and stop controlling oil flow. This leads to a loss of power and lots of noise. As there are four VANOS unit's it's not a cheap fix.

In an attempt to reduce the VANOS noise BMW fitted thicker steel to some components around 2001. This doesn't stop the seals hardening with age.

If buying one of these check the history to see if it's had new seals, if not it's a big bargaining point. Listen for a loud ticking noise from the front of the engine around 1500rpm once it's warmed up. Listen to this video https://www.youtube.com/watch?v=hUNYvwn9ivw

These cars can suffer from carbon build up in the exhaust tract, especially if used for lots of short journeys and never driven hard. The problem is the secondary air system designed to lower emissions when the engine is cold. These weren't meant to be town cars. In extreme cases you must remove the cylinder heads to clear the deposits. The secondary air system can be deleted if you prefer, but it may not be legal in some areas. Not sure if all markets even had the system, US cars certainly did.

These engines use a lot of oil, it's vital you regularly check the level and use the correct oil.

If the timing chain sounds at all rattly fit a new tensioner, it's not a hard or expensive job and could save you a fortune. To be honest this is true of most BMWs.