E34 buyers advice and engine guide....Ohh this is a long one UPDATED #blogpost
First let us look at the engines available, because this is much likely a thing which is most difficult to change. I will sort them by engine Code and not size of the engine, so do not be disturbed.
M20: Available with 2.0l (M20B20) with 129hp and 2.5l (M20B25) with 171hp. These engines were used from 12/1987-09/1989. A smooth inline six engine with great smoothness, like no other engine at that time. This engine has also its appearance in the E30 (for example mine has it…slightly tuned). Sadly the engine has its weak-spots. It has only 12 valves (every cylinder just one intake and exhaust valve), the cylinder-head breaks if it is not driven warm carefully mostly between cylinder 5 and 6, which is expensive, so becareful. The next thing is the timing belt. It is required to be changed every 60.000 km and that interval needs to be followed exactly. There is no way around it. Expensive and a mechanic will make you poor for doing that, it is not an easy Job (it took me 6 hours… I am not a mechanic, but not bad at doing stuff like that either). So allover not the best choice in your E34. There were Diesel variants of that engine (M20D24) out there….not worth mentioning, just do not buy an E34 Diesel.
M30: Ohhh boy that engine is a beast…… I had an 535i (sadly automatic) and this thing just pulled… It is like the M20 an inline six but this time with 3.0l (M30B30) with 188 hp (in production until 1990, got replaced by M50B25) or 3.5l (M30B35) with 211 hp (in production until 1992, got replaced by M60B30). Alpina build the most powerful E34 on basis to this engine the Alpina B10 Biturbo…. 360hp and tons of torque (nowadays prices around 30.000€ and rising). But the series model was not bad either. Often featured LSD, always got the Bordcomputer with check control and tons of cool equipment. Often sport suspension and yeahh I could go on. But on paper that engine is not that impressive. It has as the M20 only 12 valves, but this engine is tough as a MF. My ex car has now 312.000 km on the clock and still pulls 242 km/h on the Autobahn….Needed a rebuild though at 267.000 km which was partly my fault (I lend my buddy the car…he did not notice it was overheating… well he paid half of the rebuild so we are still cool). The 3.0l model I know from my Dads E32. same bulletproof but less low end torque. This engine has an almost perfect soundtrack for our kind of people, but it has an unhealthy attitude to empty your pockets at the gas station =)
M40:(07/1989-06/1994 Long story short, do not buy this car with that engine. Why? It did never deserve such a crappy engine. The M40B18 (1800cc, 113 hp) has tons of issues. The ones with most annoyance: Its camshaft runs in and engine looses power, timing belt snaps (Intervall 40.000km wtf.), and most important this engine does never pull a 1.5t vehicle anywhere. But if you are on a budget there is a solution:
M43: Why I use an extra line for this? Because this thing is total different to the M40. Well not really but it features a timing chain (no more intervals for changing belt), it has a better camshaft, which does not run in easy, and it has a tricky intake system which gives the engine a lot more low end torque and let it keep up at least a bit better. My brother drives an E34 518 with that engine and he is completely good with it. Fuel economy is great (8.0l/100km). My record is 6.7l/100km only Autobahn 1290 km to Nova Rock and back with 4 other people + baggage in it. So if you are on a budget get a decent E34 with M43B18 engine and you may have not that fun in terms of power, but it definitely rocks solid in terms of cruising.
There was a CNG Version called 518g only available as a Touring. It was one of the first cars working with CNG, so the gastank is a technical difference to modern cars. It has to be replaced after 10 years, which is sadly expensive and will kill the car in most cases. Only like 500 were build (exact Number is somewhere on the internet, could not find it).
So now to the most common engine the M50
M50: The M50 was build for the E34 from 09/1989 until end of production. it received a technical update in 1992 (TÜ= Technisch Überarbeitet) in which it received BMWs first VANOS unit. This engine came in the 2.0l (150 hp) (M50B20) or 2.5l (M50B25) (192 hp). It features 4 valves per cylinder and is very technical advanced for its age. But unlike many times this time it did not make it unreliable, quite the opposite is the case. My daily clocked today 268.000 km and not a sign of weakness. Those engine live long as long as you give them proper care like oil and V-belt changing. They have a timing chain so no worries here, the only thing is the weak water-pump, which should be replaced if it is the original one. In fuel consumption, well i have the M50B20 Touring with tons of equipment and lpg, but it uses around 10.9l/100km on petrol. The 2.5l version basically manages the same so if you are looking for power to consumption the 2.5l E34 is the best option out there. It is one of the best choices. I took the 2.0l because of buying price availability and because I have my M5 to have fun. Also existed an Diesel engine (M51D25) with two version, one with intercooler (143 hp) and one without (116 hp) both engines are pretty decent pieces, but actually I would never recommend to buy an E34 Diesel. Unless you want a drift missle…. M51D25 with intercooler gets easy to 175 hp and the torque makes skids easy. And if you crash even I would say… okay at least it was the Diesel.
The 525ix was the only AWD version of an E34 available.
Now the V8
M60: It came with a 3.0l (M60B30) 218hp and 4.0l (M60B40) 286 hp and not to forget the impressive 400NM (296ftlb) of torque. The engines were produced from 09/1992-end of production of the E34. Me as a German never heard of that cylinder wearing out thing which happend in the US, because we get better fuel. But that was really an issue in the US, and if you live there, this engine is not the best choice. The 3.0l engine never won my heart, maybe because it replaced the M30B35, which is one of the loveliest engines out there or because a 3.0l V8 just does not make any sense to me…. I still believe that there was a marketing guy walking into the engineers office with his Weißbier in his right hand and saying: “The US wants a V8, we need a V8!” and that thing was born. That 3.0l engine got ditched soon after last E34 went out of production, so they realized that thing was not the best idea. For the 4.0l engine… oh yes that thing is a beauty in terms of sound V8 POWEEEER. But sadly prices go near the M5 mark, which has also better suspension and a nice high revving inline six, which is the best of an BMW. Latest Models got the rare six speed manual….I would kill people only to get that transmission….psssst……
common Problems are the oil pump which loosen itself… not a good thing while driving around! Needs to be checked when buying an E34. And the US have had Problems with the block which you can read for yourself, I do not know about that thematic much, because I never had an M60 and I am German This is the only engine I never had on this list. I had even the m40 engine in an 318i E36 winterbeater.
now to the Best engines, which make you poor, but your face smiling and your heart rate goes 200 bpm-
S38:3.6l (3535ccm) 315 hp or 3.8l (3795ccm) 340 hp engines. High revving (redline 7200 rpm) race engines with an additional oil pump outside of the engine. They really just put the race engine into an E34. That was just crazy. The 0-60 time is not that impressive around 6.0 seconds. But that is just due to the fact, that they really did not care and gave it a long first gear, so that the driving gears change into each other very nice. You can drive this car like a maniac (gio tevzadze knew it). The car even received a factory LSD, M-tech sport suspension and seats. So the price tag was just 100.000 DM when it was new. A well suited 535i costed around 60.000 DM. But that sedan is just crazy. I love every second and the 24 Valves sound like a turbine going on and push you back into the seats. I could go forever, but here are the facts. The 3.6l is tougher than the 3.8. The Piston Speed is a little bit to high I think for that issue and so these engines mostly never hit 200.000 km without major repairs, while the 3.6l is basically bulletproof. Just good oil and regular service required, which is not as easy as with all the other E34, because engineers put in the race engines there is really strange design features… that waterpump really gives me nightmares and V-Belt change not that easy job you might expect (takes around 1 hour instead of like 15-20min on a regular E34). But beside that E34M5 is a dream. Handles well (leveled suspension best thing, working condition required), accelerates from 80-160 as fast as a Golf VI R32 if you really rev it, because highest power is at 6950 rpm and it holds that until redline, it enjoys every last breath…. Oh god i just want to go out and have a ride again..
So and now to the general advice for E34. They went to water-based paint in 1993 which results in rust. My E34 520i is sadly one of the worst examples of that paint. I got rid of all rust last summer, and this winter rust is back just as it was before. Doors are also a weakpoint, they rust from down to center, this is not only the case if the owner did not care, this always happens if the car is driven in winter. So if there is just rust on the doors, that does not mean the car is not worth it. It just needs work to be put on there. On the Touring, the boot-lid is a big problem for rust and for cables as well, so check if all the lights are working properly. Suspension…well depends on your budget. Levelled suspension is great and all, but if it breaks it makes you poor in like no time. So if you are looking for a nice project car go ahead E34 is always worth work on it and it will always make you smile.
So this was it for today…. I am sad, because I can not attend the #CTmeet because of work… I hate myself for that. I hope you will have a nice day there and that this article helps you to choose which E34 is best for you. If I forgot sth. comment me. When I start making videos (somewhere in May I hope) I will definitely make a Video how to inspect an E34.
This content was originally posted by a Car Throttle user on our Community platform and was not commissioned or created by the CT editorial team.