The E30 engine and car guide (did that for E34 also) Updated #blogpost
So first of all the chassis variants out there. First E30 2-door coupes were sold in 11/1982. First Cars were sold with the M10 (316 316s or 318i) or M20 (320i or 323i). Since 1983 there are the 4-door limos and Baur-Droptop cabriolets. The M20B25 engine came in 1985 and lasted until end of production, the M20B23 ended production in 1985. In 1985 first BMW Cabriolets were built with the M20B25 engine, they were produced until 1993. In 1987 the M10 engine was replaced (sadly) for the M40 engine. The M42 which was very advanced came in 1989 and lasted until end of coupe production. In 1987 the Touring got added to production and lasted until 1994, the last E30 ever build.
The Special E30, the M3 was build from 04/1986-12/1990 only 2 doors and very few cabriolets were build. S14 engine in many variants, a petrolheads dreamcar must have…..
So the engine guide
M10: The M10 made 75-105hp. This engine was sadly discontinued in 1987. On its construction the famous F1 engine with 1000hp was build, of course very very few Parts were used in that engines together, but nevertheless this engine is bulletproof. 400.000km no Problem. Add a bit of boost…..it can handle it. This engine has a timing chain and lasts longer than the most E30s will. If you are on a budget, get a pre facelifted E30 with this engine. it may consume a bit more fuel than the later M40, but repair bills will make up for that. I wanted to get me an E30 daily with this engine, but actually they are not that common anymore in Germany. You find them, but every time I look they are like a billion km away. So all in all a big thumb up for this engine on the lower end.
M20
M20: This is the only engine I really have worked on, in this list. The other ones I know from stories and reading on the Internet. This engine is pretty tough, too. But first things first, the M20B20 made 125-129hp, M20B23 150hp, M20B25 171, the M20B27 125-129 hp. I have the M20B25….it is a love-hate relationship. The engine is smooth even with a few modifications, it sounds like a maniac on drugs ready to kill anyone crossing the street. It is fun to drive, but timing belt, very easy to get a cracked head, needs often serviced, breaks a lot (maybe due to hard abuse), so engine for more qualified personal instead of your beginners working car. So enough to mine back to all the other M20s (Timing Belt Interval 60.000km, but more on the M20B27).
M20B20….basically as the M20B25, but way less power and therefor same fuel consumption….only a lower pricetag.
M20B23….The older M20B25 so already the same
M20B27…..Well this one is a bit different. It has another engine behavior. It has tons of torque low end. 230NM at 3200rpm, for an N/A engine. But it only revs, depending on the year, to 4000/4500rpm. It was build to save fuel, because the revs are low as hell on 130 km/h and so it uses “only” around 7-8l at that speed. That was pretty good back in the day. I have a weakspot for that engine, because the 325e was a special, like the E28 525e.
There was a Diesel Variant M21D24, well basically 2 variants. One with turbocharger putting down mighty 115hp and a slow one with 86 hp….well I forgot both Diesels, because Diesels are not a thing for me and E30s.
M40
M40: Came with the facelift, well about average engine with timing belt, has many problems with cams, valve-ticking, oil pump-failures and a stupidly short timing-belt change interval (40.000km). Yes this are the face lifted pretty boys you get for cheap. But they are just cheap. Of course these engines are easy to work on, but is not the best engine, the engine you do not need to work on all the time? I would stay away from this engine…. In E36 (M43 is well, though) and E30.
But then M42 ohh the Baby M3… lovely 16 Valves high rpm and 136hp from a 1.8 in 1989… ohh yes…. And this time not one of the problems from the M40…. why they just build a got sporty Version and not a good civil version of this engine from the beginning? The M42 is a tough raw engine with DOHC. It got all sporty credentials, due to the influence of the Mad M-GmbH engineers working on it. This engine is for your little bigger budget (good ones starting at 5000€) a big thumbs up. I testdrove one and fell in love with. The same day I testdrove my 325i and the price was lower and the 325i was more fitting what I had in mind. But if I would not have to choose I would have taken both.
S14
S14: The crazy race one.. Oh you have to love this high reving engine with its’ roaring 4 pot 2.3-2.5l engine.
There were M3 Evo I, M3 Evo II and only 2 months an Evo III with top of 238 hp out of a 2.5l in 1990, The 1990 5.0l Mustang had 230hp, so exact half the displacement needed. And this engine was tough. It made the E30 the Most successful Racecar ever made. Of course its easy attitude to accept modifications, easy to work on all kinds of stuff why we love the E30 was a big part of that success but That S14 engine… Ohh god it is just a hell of a car. Its`rival the Mercedes 190 2.3 Cosworth made the competition hard, and the M3 beat the Cossie Mercedes everywhere but the salesroom (The Cosworth was a better all-round car, i have even to admit as a BMW fan). Prices are exploding because everyone who is an enthusiast wants one cries!
now the general advice
The E30 is build to be fixed easy, one of the reasons why everybody loves it. But it has many rust problems like rear arches, door sills, the front window, the suspension mountings, front and rear, general rusty floor sometimes water coming into cabin from below, water coming in because drainage is not working properly and and and. The Suspension on the front needs replacement basically by rule of thumb at 200.000 km. But replacing is not that bad and you might upgrade it anyway. Just make sure to get a OEM quality wishbones and rest. If there are noises at hard acceleration that are not the tires from behind, it might be your spherical bearings. If your breaks vibrating-of course your pads, but it also can be air in your front suspension arm bearings or your rubber bearings itself are bad. E36 Parts live longer and fit in as well. If you get noises from the boot your E30s rear strut bearing (Domlager) is bad, again E36 parts are better. And then all the general stuff…. check breaking lines, check if there is water in oil, check if there is water in the cooling system, check if it burns oil like no other and and and….
So any additions or if you want to change my mind explain down in the comments. Also check out my E34 guide: https://www.carthrottle.com/post/nkld834/
Have a nice Sunday and keep save!
Comments
Actually few corrections on m20. I have a 325ix and have worked on it all the way around and can assure you the engine is pretty much bulletproof. 329tkm on clock and still has a factory gasket. You need to adjust valves every 30tkm and have a continental timing belt kit together with tensioner and water pump which has warranty of 90tkm. Few issues this engine suffers is a MAF, choke valve and viscous cooling fan. MAF has tendency to bend 2 contact button holders and therefore get them stuck at full throttle which results in engine choking. Choke valve gets moist and rusts which causes severe idle problems when engine is cold. Viscous fan fails and causes overheating engine and cracked head especially in city driving. With proper valve adjustements and regular oil changes and checking oil level every 1000km to make sure engine has enough of it (m20’s are notorious for oil consumption) the engine will run strong as a bull for over 500tkm without major problems. But I have to agree definizely not a recomended choice for someones first car.
well I said M20s are tough didnt I? i have one myself.... has minimum 200k on the clock... dont know cause speedo says 30.000 but that is not true…. Have bought it without story. It is tough and took our drift and well spirited driving punishments pretty well. I thought it was because our driving style it uses oil. My oil consumption is 1l/4000km so not that bad I guess? And it is properly serviced. BMW says every 60.000 km even with contibelts… We changed it when buying it, so I guess we are save for the next years….since only ran 10.000km in 2 years. But we faced many problems, not starting due to fuel pump, not starting due to crankshaft sensor, missfireing due to injektors and and and….
So… where is the m21? Great engine to, that everyone seems to forget about
ohh yeah forgot that one…. But I don`t think it is great….Diesel engines do not belong into BMWs…..
great post, going to stickies!
Thx, my E34 guide was more detailed ;) sadly posts like these don’t get the audience, even harder with new layout. They stick longer around, but the audience is limited to the E30 owners, sadly.
what is your average consumption with the m20b25? still looking for a e30, and got a 325iX from 89’ that might do. only have to come with good arguments to get my mother to agree to sell my actual car to get this e30 (can t do anything without her agreement sadly…)
well, my consumption is irrelevant. This E30 sees no normal daily driving. The engine is modified as far as you can and pretty much undriveable for anyone. So I guess an E30 325ix needs around 11 l Super.