TIMM'S 8-SERIES REPAIRS
 AND INFORMATION

I've always wanted an 8-Series, it is just the shape of the car that is so attractive, especially seen from the rear-quarter with the quad exhaust steaming away. Having owned a V8 730i E32, a 735i E38 and two 740i E38's I thought it was time I went for the ultimate model, the E31 8-Series. Being a long-term V8 lover I chose the 840ci. I'm now on my second E31 after a very happy introduction with a '97 Orient Blue Sport.

The E31 had a short life with the first model being the 850i, which utilised the 5.0 Litre M70 V12 engine from the 750i. As with the 750i, the engine was mated with the 4-speed electronically-controlled automatic gearbox. The problem was that although the car was fast, it wasn't any faster than the 750i which was better equipped and had rear seats that could actually be used. However, there was no argument that the 850i certainly went around corners a lot faster.

The E31 saw the introduction of BMW's 'Z-axle' which was further developed on the E38 7-Series. This rear axle helped the rear-end stability, something that the E32 couldn't boast. Once the 7-Series rear-end lets go, it lets go in a big way whereas the 8-Series has a controlled feel that gives great confidence at the limit of adhesion. As far as performance goes, this is where the 8-Series excels over the 7-Series. There is little to choose in a straight-line but once on the twisty stuff the 8-Series will disappear in the distance.

My personal preference is for the V8 models, the first of which was introduced in 1992 in the 840i. These were not cast-iron 'American' V8's though, the BMW M60 was a lightweight all-alloy V8 which sported 32 valves, 4 overhead camshafts, 8 individual ignition coils and sequential fuel-injection. The 740i developed 286 BHP and 400 NM of torque which was coupled to an adaptive 5-speed automatic gearbox.

A 1999 E31 840ci - The 840ci has the later M62 4.4Litre V8 which is married to the Steptronic gearbox

The early 4-Litre 840i sported the M60 V8, these models are unpopular in the market due to the Nikasil process which was used to provide bearing surfaces on the machined-aluminium bores. However, the Nikasil issue has been highly exaggerated and the M60 V8's (in 2013) are just as likely to provide a long service life as the later M62 engine.

The 840ci Sport models sported the rear-splitter, front splitter and re-shaped wing-mirrors from the 850csi. The alloys on this car are the classic throwing-stars, the 'throwing star' is not structural and the spare sports plain black ribs.

Although production carried on until May 1999, the M62TUB engine was never introduced. In pure performance terms this is a shame. The technically-updated (TU) version of the M62 included the Vanos variable valve timing. The Vanos smoothed the idle (which was always a bit lumpy), flattened and increased the torque. This would have made the 840ci a real beast just as the late 740i's are. It would also have introduced the fly-by-wire throttle system and simplified the ASC/DSC/ABS system, a real benefit to the late 740i's. Sadly, this was not to be and the last 840ci's were produced with the M62B engine which requires much higher revs to achieve power. Still, this is hardly a slow car with a 0-62MPH time of around 7 seconds (quoted as 6.7s with the M62B in some publications).

 

The pop-up headlight units contain projector dipped-beams and fog lights with a plain main-beam. As the headlight units are lowered when not in use and would not respond quickly if required to flash, a pair of oblong units are provided below for this purpose. With the lights on main-beam and the front fogs switched on, the 8-Series provides eight 55W lights to illuminate the road!

The Steptronic gearbox as fitted to post-1996 cars provides both manual and automatic control. The switches to the left and right of the shifter are for the heated seats. Above and to the right of the shifter is the ASC+T (Automatic Stability Control plus Traction) switch and to the left is the alarm LED.

Classic-lines of a my 1999 840ci. When the windows are dropped and the sunroof opened it becomes a convertible with a steel roll-cage (in effect), the best of both worlds

This site is for anyone that owns an E31 BMW 8-Series and wants to repair the car themselves. The information on this site is either from my own repairs (BLUE buttons) or from information I have found whilst investigating problems (GREEN buttons). The SILVER buttons are for information on the cars systems, owner's manuals and circuit diagrams. I am the current owner of a 1999 840ci Sport Individual and an ex-owner of a 2000 740i E38 Individual a 1997 840ci Sport, a '93 E32 730i V8, a '98 E38 735i V8 and a '99 E38 740i. 

I am an Administrator (Timm) on The 7 Series Register which (in my opinion) is the best Forum for 7-Series cars, we have now started an E31 section as the 8-Series shares many parts with the 7-Series E32 and E38. All these fixes and information can be found on the Forum plus a great deal more by experts in all versions of this great series. My initial help came from this Forum and this gave me enough confidence to perform other repairs.

The 7 Series Register is free to join, there is no need to register but please do and you will find a world of friendly 7-Series owners ready to help you! Some of the repairs are pretty straightforward, some are pretty awkward but none of them are that difficult. Just like most of The 7 Series Register members I am not a mechanic and consider myself a rank amateur. However I am lucky to have the experience of our members and my own experience of my four 7-Series and two 840ci's, the greatest asset we all share is knowledge of what normally goes wrong and how to fix the problems!

It is worth mentioning that the cars worked on are UK (right-hand drive) models. There are a few differences between RHD and LHD variants. Sources of information are the circuit diagrams for the E31 (available from this site), the TIS (Technical Information System) and the ETK (electronics part catalogue). All three are usually available from Ebay for a few quid. Be aware though, that the TIS has little information on the E31, it is better to select the E38 for information on the M60, M62, M70 and M73 engines. The brilliant RealOem website is excellent for finding the correct part numbers and for exploded diagrams.

I am also a musician, so click on the 'Chase' tab and download some music while you peruse the information!