The BMW 3-Series E21 was produced from ’75 to ’83, although all but the entry-level variety stopped production in ’82. In that time, BMW built 1,370,000 of them.
The first 3 Series, or E21, was a two-door. Styling was by Paul Bracq, fresh from the first 5 Series, and the two cars had a strong resemblance. From 1977 to 1982, there were targa-top ‘Hardtop-Cabriolets’ by Stuttgart-based coachbuilder Baur, who built many BMW convertibles, but only about 3000 were sold.
The first engines were four-cylinders, with an injected 2-litre in the top-model 320i. Two years later came a 2-litre six-cylinder to make a new top-model 320 and, in 1978, a 2.3-litre six which created the highly desirable 323i. From ’80, the 316 went from 1.6 to 1.8 litres, and gained in the torque department. The UK otherwise didn’t get the 1.8-litre engine, nor the detuned 1.6-litre, run-out 315 model.
Suspension was by MacPherson struts at the front and semi-trailing arms at the rear, along with unassisted ZF rack and pinion steering. You got ventilated front discs with rear drums and a servo, but there were rear discs on the quickest 323i.
The first thing strikes you when you get behind the wheel is how the centre console is angled towards you. It gives the car a tight-fitting feel, like a pair of gloves – but the feeling isn’t one of being cramped.
There’s a certain sporting rasp about the four-cylinder engines which doesn’t translate into as much urge as you’d expect. Even so, the later 1.8-litre 316 accelerates pretty well. The sixes are a totally different experience: smooth and keen to get on with the job, they are really great engines of their time.
The Achilles’ heel of these small BMWs was always what Motor magazine called "snap oversteer". It’s nothing to worry about, but the semi-trailing arm rear suspension is subject to sudden camber changes on the limit – if you discover this on a wet road, you could lose the car. It’s not helped by a wooden feel to the steering at high speeds. Otherwise, the handling is little short of admirable for a mid-1970s saloon.
Early cars mostly have four-speed ’boxes. From ’79, there was a five-speed with overdrive top, and a close-ratio five-speed that was rarely specified. There were autos too, but these were disappointing.
WHAT TO LOOK OUT FOR
1 One reason why this best-seller is pretty uncommon these days is corrosion. The cars were not undersealed at the factory, and only fastidious owners paid extra to have the job done when the cars were new. They rust – and how! – so your first check should be for the more obvious signs. Look at the rear wheelarches, front wings, door bottoms and sills, and the rear valance under the bumper. Rust gets hold at the front corner under the side windows, and under the rear windows, too.
2 Having checked all the usual rot spots, now turn your attention to the less obvious places. Carefully check the seams of the bonnet and boot, the corners of the main floor, the boot floor, around the jacking points and around the rear suspension towers. Springs have been known to punch through. No rust? You’ve found a good one.
3 On the gearbox front, don’t worry about some whining from the lower gears. That’s normal. However, the clutch hydraulics are prone to leaks, so it’s wise to check for fluid on the carpet and on the foot pedals. If the car’s an automatic, make sure the changes are smooth. Surges and lurches suggest worn friction components in the clutches, so if other things are urging you to buy the car, budget for a replacement gearbox.
4 The original Solex carbs often gave trouble, and many owners replaced them with Webers. The problem was particularly acute on six-cylinder cars with the 4A1 carburettor – although that might be because owners expected more from their engines than the four-cylinder models. The fuel injection is a Bosch K-Jetronic, which is a mechanical system and not too hard to diagnose and fix if it plays up.
5 On four-cylinder engines, listen for top-end noise. Water pumps usually last for 70,000 miles, and you’ll hear one that’s on the way out. Cam chains wear, too, and you’ll hear that warning ringing sound. Poor performance could be caused by worn cam lobes, which is a common fault on high-mileage engines.
6 Six-cylinder engines, especially in the 323i, were often thrashed. The 323i in particular has a reputation for cracking its cylinderhead, so make the usual checks for water in the oil or otherwise unexplained water loss. Sixes also had a belt-driven overhead camshaft. This isn’t particularly troublesome, but check when it was last changed.
7 If there are odd noises from the front suspension, suspect the anti-roll bar buses – they tend to shear after hard use. If the steering feels notchy, then you’d better look at the steering rack.
8 The braking system doesn’t give a lot of trouble, but it’s worth checking the remote linkage to the servo. The servo was always on the left, even on RHD cars, and the linkage can corrode. The 323i models had rear discs (all the others had drums), and on a car which hasn’t been used for a long time you’ll probably find that these have rusted very badly.
9 With the Baur Hardtop-Cabriolets, check that all the roof components are present. There should be a removable section over the front seats and a collapsible fabric section at the rear. Check the integrity of the rear window, and double-check the seals and clamps. If the vinyl pillar trim has been damaged, so budget for professional replacement.
10 Options you can add from scrappers are Mahle multi-spoke alloys, a limited-slip diff, sports suspension and Recaro seats.
An E21 3 Series may not be the most glamorous of 1970s saloons, but it makes a great starter classic. It’s affordable both to buy and run, and will cope easily with modern traffic. However, it’s very important to buy the very best, because current prices don’t justify expensive repairs. A full-scale restoration would have to be a labour of love.
The four-cylinder 316 was the best-seller, followed by the six-cylinder 320, so these are the models that will be most readily available. It’s certainly worth going for the post-September 1979 316 if you can find one, because the 1.8-litre engine gives more torque and is correspondingly more flexible, although power and top speed are the same as with the older 1.6-litre engine.
As a 323i isn’t quick by modern standards, we’d go for a six-cylinder 320 which hasn’t been treated as a boy-racer’s delight.