Technical

Like any BMW, the E30 is a complex precision machine, precision-built and designed to last. But even the simplest of machines needs maintenance occasionally, so keep your E30 running the way it should, it helps to familiarise yourself with the design, and the components. The Technical section of the E30 Zone Wiki is your one-stop source for maintenance tips, common problems, upgrades and troubleshooting.

Your E30 is broken down into separate sections, to help you understand each part in turn.

Engines

To maintain and repair your engine, you need to know what lump you have under the bonnet of your E30. Below is each engine, listed by model and year, for the E30. By clicking on the engine, you will have access to information regarding Maintenance, Cooling systems, Fuel, Intake, Exhaust and Electrical systems, as well as Common Problems and Upgrades.

Name	Volume	Engine	Valvetrain	Fuel	Output	Torque	Engine code	Years
316	1766cc	4cyl	SOHC 8V	Petrol	99hp (66kW) @4500 rpm	103ft/lb (140Nm) @4250 rpm	M10B18	1982–1990
316i	1596cc	4cyl	SOHC 8V	Petrol	102hp (75kW) @4500 rpm	105ft/lb (140Nm) @4250 rpm	M40B16	1988–1995
318	1766cc	4cyl	SOHC 8V	Petrol	104hp (77kW) @4500 rpm	103ft/lb (140Nm) @4250 rpm	M10B18	1982–1990
318i	1796cc	4cyl	SOHC 8V	Petrol	113hp (85kW) @4500 rpm	122ft/lb (165Nm) @4250 rpm	M40B18	1987–1995
318iS	1766cc	4cyl	SOHC 8V	Petrol	140hp (104kW) @4500 rpm	127ft/lb (172Nm) @4250 rpm	M42B18	1989–1991
320i	1766cc	6cyl	SOHC 12V	Petrol	123hp (92kW) @4500 rpm	0ft/lb (0Nm) @4250 rpm	M20B20	1982–1985
320i	1766cc	6cyl	SOHC 12V	Petrol	127hp (95kW) @4500 rpm	0ft/lb (0Nm) @4250 rpm	M20B20	1985–1991
320iS	1990cc	4cyl	DOHC 16V	Petrol	192hp (143kW) @6750 rpm	155ft/lb (210Nm) @4750 rpm	S14	1982–1990
323i	1766cc	6cyl	SOHC 12V	Petrol	139-150hp (104-110kW) @4500 rpm	0ft/lb (0Nm) @4250 rpm	M20B23	1982–19850
325e	1766cc	6cyl	SOHC 12V	Petrol	101hp (75kW) @4500 rpm	103ft/lb (140Nm) @4250 rpm	M20B16	1982–1990
325i	1766cc	6cyl	SOHC 12V	Petrol	101hp (75kW) @4500 rpm	103ft/lb (140Nm) @4250 rpm	M20B25	1982–1990
325iX	1766cc	6cyl	SOHC 12V	Petrol	101hp (75kW) @4500 rpm	103ft/lb (140Nm) @4250 rpm	M20B16	1982–1990
M3	2302cc	4cyl	DOHC 16V	Petrol	197hp (147kW) @6750 rpm	176ft/lb (0Nm) @4750 rpm	S14	1986–1988
M3	2302cc	4cyl	DOHC 16V	Petrol	212hp (158kW) @6750 rpm	170ft/lb (0Nm) @4600 rpm	S14	1989–1991
M3 Evolution	2302cc	4cyl	DOHC 16V	Petrol	197hp (147kW) @6750 rpm	176ft/lb (0Nm) @4750 rpm	S14	1987–1987
M3 Evolution II	2302cc	4cyl	DOHC 16V	Petrol	217hp (162kW) @6750 rpm	181ft/lb (0Nm) @4750 rpm	S14	1988–1988
M3 Sport Evolution	2467cc	4cyl	DOHC 16V	Petrol	235hp (175kW) @6750 rpm	177ft/lb (0Nm) @4750 rpm	S14	1990–1990
324d	2443cc	6cyl	SOHC 12V	Diesel	84hp (63kW) @4600 rpm	112ft/lb (152Nm) @2400 rpm	M21D24	1985–1993
324td	2443cc	6cyl	SOHC 12V	Diesel	114hp (85kW) @4800 rpm	162ft/lb (220Nm) @2400 rpm	M21D24	1985–1993

Maintenance

All engines need looking after, and while simple jobs like Oil Changes are standard to all E30s, some jobs are specific to either the 4-cylinder or 6-cylinder engines. Click on the engine model for your car to get specific information:

• M10
• M20
• M40
• M42

The following topics are standard maintenance tasks to keep all engines running smoothly

• Cleaning the Injectors

Upgrades

Engine Swaps

While every E30 is a sublime driving machine, the desire for more power leads many to look at their options. Since many E30 engines are unsympathetic to "tuning" without spending serious cash, the following engines are popular choices to replace your current donk:

M50 M52 M30

Drivetrain

Gearbox

Upgrades

A Z3_short_shifter_conversion will help you change gears quicker.

Differential

The following were fitted to each E30:

It was possible to order a Limited_Slip_Differential from the factory, with the ratio suitable for the engine in your car.

Maintenance

The differential will require an oil change every now and then. Small-case diffs take 0.9 litres, medium-case diffs require 1.7 litres.

Upgrades

Changing the differential will do one of two things. Fitting a lower differential will give better fuel economy at cruising speeds, at the cost of reduced acceleration. Fitting a higher differential will get you away from the traffic lights quicker, but will make your engine rev that much higher on the motorway, with the noise and fuel bills that go with it.

When upgrading your engine, upgrading your differential at the same time is almost mandatory.

Brakes

While moving in the E30 is an utterly delight, the need to stop moving is sometimes necessary. For that reason, the E30 was fitted with front discs on all models. The smaller-powered 316 and 318 saloons were fitted with rear drum brakes, while all six-cylinder models and Tourings had rear discs as standard.

For more information on the E30 braking system, check the Brakes.

Upgrades

If needed, E30 brakes can be improved in a number of ways. While some choose to upgrade to rear discs, others prefer to use bigger discs and callipers from newer BMWs, which necessitates an upgrade to a 5-bolt hub.

Suspension

All E30s are fitted with McPherson struts for front suspension, bolting up to a single control arm at the bottom. This is reinforced by an anti-roll bar connecting the control arm to the front subframe. The rear wheels have independent suspension of springs and shocks, and are connected to the rear subframe via trailing arms. Another anti-roll bar clamps the trailing arms to the body.

Maintenance

Over time, the rubber suspension components will dry out, harden and perish. This inevitable deterioration means that all the bushes will need replacing at some point. Renovating the bushes with original rubber components will dramatically improve the ride quality.

Upgrades

The front end of each E30 is designed to carry the weight of its engine. If you've gone through the labour of an engine swap, you'll want to increase the front struts to cope with the heavier weight of the new engine, especially if you've upgraded from four to six cylinders.

The rear end can also get tired over time, after 20 years of tail-sliding abuse. Upgrading the rear suspension can yield a much tighter driving experience for these cars.

Steering

Maintenance

The steering system is relatively simple on an E30, and as such the main requirements are to keep the rack in good condition and topped up with fluids. Changing the fluid regularly will keep the rack clean, but you must also pay attention to the track rod ends

Upgrades

While the steering of an E30 is a charm of feedback-response, neither too heavy or too light, many of the more spirited drivers find the standard rack too long, in the sense that it takes too many turns from one full lock to the other. Fitting a faster rack from a BMW Z3 is a common and simple upgrade, but for those looking for bigger increases, fitting a rack from an E36 M3 can bring dramatic improvements.

Body Styles and Fittings

The E30 was offered in a number of body styles. A 2-door and 4-door Saloon, Cabriolet and Touring

Electrical

The E30 loom is a monstrous labyrinth of wires, all colour-coded, so that you can easily trace exactly which wire does what. All wires inside the cabin are part of a one-piece loom that runs through the bulkhead on the passenger side of UK cars, where they meet the Fuse Box.

Maintenance

Ensuring that all the fuses in your Fuse Box are the correct rating is essential in preventing electrical fires. If you are experiencing blown fuses, DO NOT insert a fuse with a higher rating than that in the diagram.

Tables

Tables can be somewhat tricky. Good information can also be found on the wikipedia site: Tables Help

Tables on this site should be created like the below:

Please note the class="wikitable" attribute.

{| class="wikitable"
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|We
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|E30s
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This should look like:

Table Title

First Column Header	Second Column Header	Third Column Header
We	Love	E30s
Old	Skool	Cool