BMW E30 Buyer’s Guide

The BMW E30 is one of those cars that has an indescribably magical aura surrounding it. By the time the E30 chassis reached US shores in 1984, it had already been praised around Europe as THE premier German saloon car to have. In the subsequent decades, BMW would continue to produce the 3-Series with a unique philosophy in mind: making daily driving fun. That philosophy originated with the E30.

The 1990s, 2000s, and 2010s have now passed us by and left us with cars that would be unrecognizable to folks in the 20th century. Modern cars are heavy, complicated, and artificial. A connected driving experience in a modern car is a pipe dream for those who know what performance cars felt like in the 80s and 90s. For that reason, many people looking for a pure and analog driving experience are looking back to a time when a 12.5” touchscreen wasn’t a standard feature. Or a feature at all.

The BMW E30 epitomizes the driver’s car mentality. Nothing stands in the way between your right foot and the road in an E30. That is why they are fetching never-before-seen premiums on auction sites and Craigslist nowadays. As prices continue to climb, it’s only a matter of time before they enter the grail market; Side by side with other unattainable classics like the Mazda RX-7 or the Porsche 964.

If you have ever dreamed of owning an E30, it truly might be a case of now or never, unless you happen to be a leading heart surgeon or the Prince of Brunei. This article is meant for those looking to pull the trigger. In this E30 buyers guide, we’ll cover the basics of purchasing a BMW E30 and what to look out for when doing so.

Early vs Late Models

Beyond the availability of those three models, it is also important to consider the production year of your prospective E30. E30s from model year 1984 to model year 1988 are considered “early model” cars or “pre-facelift” cars in the BMW community. Along a similar vein, E30s from model year 1988 to 1993 are called “late model” or “post-facelift” cars. While the differences between early and late model E30s are primarily cosmetic, it is important to know what you want in this respect.

Early vs Late Model E30 Aesthetic Differences

Early model E30s feature large metal bumpers to meet early 80s US safety standards. The E30 community often calls them “diving board” bumpers as they stick out far beyond the body. Modifications can be made to early model cars to “tuck” the bumpers inward so that they protrude far less. Early model E30s also had a different set of front and rear valances than late model cars. Personal preference plays a huge part here, as some like the look of the early model valances better while others prefer the late model look. 

Late-model E30s feature more streamlined plastic bumpers that stick out far less than the metal bumpers on early models. 1988-1993 models also have a different array of front and rear valances that are a bit more intricate and detailed than those on early models. Late models also have larger rear lights than early model cars that appear slightly more rounded. Lastly, in terms of aesthetics, late model E30s feature ellipsoid headlights as opposed to sealed beam headlights found on early models.

Early vs Late Model E30 Performance Differences

While aesthetic differences are important to note, it is the performance differences between early and late model E30s that matter the most. Both early and late model E30s have enormous potential as far as aftermarket support is concerned. However, the differences between early and late model engines and suspension components make modifying late models easier.

Starting with suspension differences, early model E30s feature 84mm front strut housings, while late models feature 85mm front strut housings. While it might not seem like a big deal, the smaller strut housings on early model E30s limit the amount of aftermarket suspension options. E30 coilover and strut/shock setups are much easier to find for late model E30s, so remember that if you are looking to build a track-spec E30. 

As far as engines are concerned, there are some significant differences, primarily concerning 325i/is cars. The only engine that bridged the early/late model facelift was the M20B25 found in the 325i/is. Late-model M20B25s have a few key differences over early model M20B25s. M20B25s in late model E30s have a different wiring harness and O2 sensor setup. They also feature an overhauled cooling system, as BMW quickly realized that the early model system is weak and prone to issues.

There was also a major difference between the early and late model 325e/es M20B27 engines as well. We’ll cover the 325e/es in greater detail below, but the primary difference between early and late model M20B27 powered cars is the design of the cylinder head. 1988 325e/es E30s featured the higher-flowing cylinder head from the M20B25 and therefore revved higher and produced more power than early model 325e/es E30s. Late-model 325e/es E30s were only available in 1988, as their production ended that year.

Model Differences

Beyond the differences between early and late model E30s, there is a multitude of E30 variants to choose from. Compared to the rest of the world, the US was stiffed on E30 variants. While the rest of the world saw quite a few E30 variants with a wide array of engine choices, the US only received a few. When it comes to US-spec E30s, you have four main models to choose from. Those include the 318i/is, 325e/es, 325i/is, and 325ix. The E30 M3 was also available for purchase in the US, however, the ludicrous price tag and high demand have relegated it into a league of its own. For now, we’ll just discuss the non-M variants.

Before we tackle the different E30 variants individually, let’s first discuss the meaning of the letters that hang off of the end of their number designations. There are four letters that you need to keep in mind when dealing with model suffixes. Those are i, e, s, and x. If an E30 model has an “i” in its model designation, that means that it is fuel-injected. The “e” designation stands for economy. A trailing “s” denoted “sport,” while an “x” revealed the presence of all-wheel drive.

The only designation that might need a bit more clarification is the “s,” or sport designation. While the others are pretty self-explanatory, the “s” designation- exemplified by 318is, 325es, and 325is models- has a bit more to it. All “s” designated E30s were only available in 2-door or coupe form. “S” models also came with some additional aesthetic and performance upgrades. These included a front spoiler with integrated fog lights, a rear decklid spoiler, 14” BBS basketweave rims, bolstered sport seats, thicker sway bars, stiffer shocks, and front springs, and a three-spoke M-Tech steering wheel.

318i/is

The 318i is the most common E30 variant found in the US, and a beloved model by many enthusiasts. Early 318i models utilize the 1.8L 4-cylinder M10B18 engine that was also found in the previous generation E21 3-Series. The 318i produces a meager 105 horsepower and 107 lb-ft of torque, which is significantly less than the other 6-cylinder powered E30 variants. Due to the M10s 4-cylinder layout, it weighed significantly less than the M20 engine found in other E30s. 

Late-model 318i/is saw a different engine. The M42 engine replaced the M10B18 in the 318i/is, but still retained a 4-cylinder layout. After the E30 facelift in 1988, 318 E30s were only available in 318is spec. Late-model 318is’ saw a serious increase in horsepower and torque to 134 horsepower and 127 lb-ft of torque. After the 1988 swap to the M42, the 318is was given the nickname “mini-M3,” as the high-revving and spritely M42 engine was the most similar to the 4-cylinder S14 engine found in the E30 M3. While there is obviously quite a big difference between the cars, enthusiasts still seek out late-model 318is as one of the most in-demand E30 models.

325e/es

The 325e/es E30 variant is another common variant found in the US.  During the fuel crisis of the mid-1980s, BMW wanted to create an E30 variant that sacrificed a bit of performance for better fuel economy. The result was the 325e/es. Unlike the 4-cylinder powered 318i, the 325e/es is powered by a straight-6 M20B27 engine. As mentioned earlier, the “e” in the 325e’s designation stands for efficiency, which was the primary target for the model. The M20B27 is often called the “eta” engine in the E30 community, which is the Greek name for the letter e.  

The M20B27 engine is an interesting engine in the E30 lineup as it has a larger displacement than the other M20B25 engine used in the more powerful 325i/is, while also having less power. 325e/es models have the second least amount of horsepower in the non-M E30 lineup with between 122 and 127 horsepower. However, the 325e/es has the most torque of any E30 variant with 177lb-ft at its disposal. To preserve fuel economy, the M20B27 is highly restricted in terms of its rev range. While the M20B25 can rev to 6,700 rpm, the eta can only manage a 4,800 rpm redline. The M20B27 aimed to keep revs low and torque high and preserve fuel economy. 

The M20B27’s characteristics were changed dramatically following the E30 facelift in 1988. During the 1987 production year and into 1988, the Eta engine saw a dramatic refresh which livened it up dramatically. The late-model engine design used the “885” higher flowing cylinder head from the 325i model. It also featured new pistons, a newer engine management system, and a larger intake manifold. The rev-limiter was increased to 5,300 rpm, and the exhaust is routed through two pipes instead of one.

Due to the increased performance, E30 enthusiasts have nicknamed 1988 325e/es with the 885 head the “Super Eta,” which is another highly sought-after E30 model.

325i/is

The 325i/is E30 variant is the second most common model in the US and unquestionably the most sought after. The 325i/is’ main selling point is the M20B25 engine. The M20B25 engine is the most powerful engine offered in the E30 platform, producing 167 horsepower and 164 lb-ft of torque. Considering that the 325i/is weighs a bit over 2,600lbs, the power-to-weight ratio is quite good. The 325i/is also features a much shorter 3.73 rear end when compared to the 2.93 rear end found in the 325e/es. In 325is models, a limited slip differential was included, making it feel much livelier around corners.

Of all of the E30 variants, the 325i/is the model designed with performance in mind. While the other models in the range can be modified to reflect the performance seen from the 325i/is, the M20B25 powered 325i/is is the most powerful, best equipped, and most modifiable E30 model. The M20B25’s 9.7:1 compression ratio makes it ripe for forced induction and, as the M20 is an extremely reliable engine, turbo kits can be thrown on with relative ease and with few long-term issues.

Pricing

This section is meant to overview what you should expect to pay for an E30 based on model and condition. With that being said, E30 prices are climbing consistently at this point and are expected to only climb higher. Generally speaking, 6-cylinder models are the most in-demand and fetch prices much higher than 4-cylinder models. The 325is is the most sought-after due to its M20B25 engine and is typically the most expensive model available. Late-model cars also go for higher prices, as people tend to prefer their aesthetics over early model cars.

E30 Buyers Guide – 318i / is – A driver condition 318i in the US typically goes for around $4-5,000 in today’s market with prices reaching closer to $6,000 for a clean, unmolested example. Late-model 318is’ go for even more than that, with prices for a good example closer to $7,000-$8,000.

E30 Buyers Guide – 325e/es – Due to the fact that the eta models have the less desirable M20B27 engine, prices for a driver’s example fall closer to $3,500-$4,000. Well taken care of 325es can go for upwards of $6,000, with the highly in-demand 1988 ‘Super Eta’ cars going for $7,000-$8,000 in good condition.

E30 Buyers Guide – 325i/is – As the most sought-after model in the E30 lineup, 325i/is are skyrocketing in price in recent years. Even fixer examples are frequently seen going for $4,000-$5,000. A running and driving 325i typically goes for around $6,000-$7,000 in the current market. It isn’t uncommon for well taken care of 325is to sell for 5 digits. Expect to pay $10,000-$15,000 for a well-sorted 325i.

What to Look Out For

Now that we have covered the E30 basics, let’s move on to talking about what to look out for when purchasing one. One of the primary reasons that people are interested in E30s in the first place is their superior engineering. Buy and large, E30s are dependable, comfortable, and easy to maintain. 

However, with any car more than three decades old, age takes its toll. In some ways, BMW’s over-engineering of the E30 leads to additional problems as they age. E30s were built with sophisticated onboard diagnostic capabilities and complicated electric components for the time, some of which are prone to failure. With that being said, E30s don’t encounter any late-life issues that are uncommon for other cars the same age. Here are some problem areas that you should look out for when purchasing an E30:

Rust Issues

As we stated above, rust issues on 30+-year-old cars aren’t a problem specific to E30s. While rust might not be an issue that only affects E30s, it is a highly pervasive issue among quite a few examples. If you are considering purchasing an E30 from the Northern US or East Coast, looking for rust is even more imperative. There is a huge difference between surface rust and serious rot to integral areas. Here are the main places that are prone to rust on E30s:

• Jack point pinch welds on either side of the car
• License plate light bezel
• Floor pan
• Rocker panels
• Battery tray (can be found in the trunk on the passenger side and in the engine bay)
• Sunroof
• Rear subframe
• Rear shock tower
• Tail light bezels (also check under the trunk carpet around the tail light area)
• Rear fender arches
• Base of the windshield

Checking these common spots for rust will give you a pretty good indication of whether the E30 you are looking at might have some more serious rust issues. 

Other problematic areas include the underside of driver and passenger side doors and the front end of the hood where debris has eroded away the paint. Rust on aesthetic panels isn’t a huge deal though, as most of them can be replaced cheaply with still available factory parts or parts from donor cars. 

Truly difficult areas of rust to manage are the floor pan, battery tray, and rocker panels. These areas are extremely difficult to repair for even experienced metalworkers, so pay special attention to these areas to prevent costly repairs in the future. Generally speaking, if the E30 that you are considering has rust in any of these areas, look for a different car.

Engine Inspection

Nearly every engine provided in the E30 lineup is known for strength and reliability. This is especially the case for M10 and M20-powered E30s. With that being said, the life expectancy for all E30 engines is completely dependent on consistent maintenance and care. Ideally, the previous owner would be able to provide detailed service records for the car, detailing previous maintenance. If they aren’t able to provide records, it is a good idea to refresh integral engine components that are known to be weak or fail.

BMW M10 Inspection and Issues

We’ll start with the M10, which powered early model 318i models. Overall, the M10 is known to be a reliable engine due to its simplicity. The M10 was developed in the 60s and retained its overall construction well into the 1980s. 

The three most common issues on M10 engines are cam rocker slippage, a failure-prone thermostat, and carburetor issues on very early model 318i. Cam rocker issues are common if the M10 has been run hard during its lifetime. Extended high revs can cause the tip of the rocker arm to slip between the valve stem, causing the retainer to crack in half. This is a costly issue to resolve, as it requires the cylinder head to be opened and repaired. 

M10 thermostats were brittle and prone to failure from the factory, let alone 30 years on. If the 318i that you are looking at is still running, chances are that it had its thermostat replaced at some point. An improperly functioning or stuck thermostat can cause serious cooling issues that can do terminal long-term damage to the engine. If there are no records of a thermostat replacement having been done, it is a good idea to replace it soon after your purchase. 

Lastly, and this only pertains to 1983-84 318i’s, carburetor problems plagued the M10 from the factory. The stock Pierburg 2BE carburetor is known to be insufficient and problematic. Carburetor issues can be easily diagnosed on early M10 E30s, as a bad carb will cause the engine to run extremely rough or not start altogether. Gas mileage is also terrible on cars with faulty carbs.

M42 Inspection and Issues

Late-model 318is are powered by the highly praised M42 4-cylinder which also has its problems, primarily due to age. The primary areas of concern for the M42 are the cam chain roller gear retaining bolt and the rubber gasket at the front of the cylinder head. 

On high-mileage M42-powered cars, the retaining bolt that holds the cam chain roller gear in place has been known to snap if unmaintained. Once again, if the E30 is still running, chances are that this issue has been resolved in the past. However, if there is no evidence that it has been fixed, it is a good place to start. 

High mileage M42s also have issues with rubber gaskets and components wearing significantly from years of service. The most problematic is the rubber profile gasket at the front of the cylinder head. If it is cracked or worn, the gasket will allow coolant to get into the engine oil. A common fix for this issue is upgrading engine components with later-developed E36 parts.

M20 Inspection and Issues

Finally, let’s talk about the M20 engine found in 325e/es, 325i/is, 325ic, and 325ix E30s. The M20 is perhaps the most reliable and durable engine of the entire E30 range. It does, however, have its own unique quirks and areas of special attention.

The most important maintenance item on M20 engines is the timing belt. The M20 motor is notorious for needing frequent timing belt maintenance. The M20 is an interference engine, meaning that if the timing belt snaps, you’ll be lucky if the only thing that you need to replace is the top end. For that reason, it is extremely important to change an M20’s timing belt every 50,000-6,000 miles, or every 5 years. If the previous owner isn’t able to provide timing belt service history, it is a good idea to do so soon after purchase.

M20s are also known to have issues with cylinder head hairline cracks. Cracks tend to happen under the front cam journals, which allows coolant to leak into the engine. The best solution to this is purchasing a quality used cylinder head. While it is possible to repair cracks in the cylinder head, replacing it with an undamaged head is the better option.

Cooling System Issues

E30s are known for having underperforming cooling systems. Late-model cars saw an improved cooling system, but even late models often have cooling issues. When purchasing an E30, it is a good idea to let the engine run for a few minutes and monitor the temperature gauge. If the needle moves past the center mark, there may be an issue with the cooling system.

The most common issues include a weak fan clutch, broken auxiliary fan, clogged radiator, failing head gasket, or stuck thermostat. If the car is overheating while stationary, the fan clutch is most likely the issue. While all of these issues vary in terms of expense and ease of repair, it is a good idea to refresh as many elements of the cooling system as you can. This is doubly true for an E30 without service history.

Common Sources of Leaks

At this age especially, it is extremely common for an E30 to be leaking fluid from a number of areas. The most common leak sources include the valve cover gasket, oil pan gasket, rear main seal, and oil filter. All of these leaks have varying levels of severity and should be addressed if you notice a significant amount of oil on the ground or accumulating in spots around the engine. Adding to that, it is extremely important to check your oil level frequently due to these leaks.

Interior Inspection

In the 80s, BMW was beginning to include some more sophisticated electrical systems in their cars. Some of the most notable electrical inclusions included an onboard systems check panel, powered sunroof, and service indicator lights. While some of the systems were designed for longevity from the factory, others are known to fail with age. 

When stepping into an E30, the first thing that you should do is make sure that all of the electric systems are working properly. This generally includes cycling through the power windows and sunroof (if the car is equipped with them), and making sure that the roof-mounted check panel is in working order.

The onboard check panel – located above the rearview mirror – is an extremely useful feature found on all 6-cylinder E30 models. It allows for quick diagnostics of all of the main systems in the car. If lights are illuminated on the panel, it means that there is an issue with the corresponding system. The check panel is typically extremely accurate unless a sensor is disconnected or damaged. A quick glance at the panel will give you a good indication of any problem with the car, which is good from a buyer’s perspective. 

It is also extremely uncommon to find an E30 without any interior blemishes, especially on cars with cloth interiors. Almost every E30 example that has survived until 2022 will have a cracked dashboard. BMW no longer manufactures E30 dashes, so finding one without cracks is almost unheard of. Common solutions are dash covers to hide the cracks, or flocking the dash and performing repairs during the process.

Faulty interior gauges are also extremely common on E30s. Non-functional fuel, rev, and temperature gauges are the most common to have issues. Fortunately, they aren’t very costly to repair and can be fixed with relative ease. The most difficult part is removing the gauge cluster from the car without doing additional damage to the dash.

What To Look For On A Test Drive

If you arrive at a point where the E30 that you are considering buying has passed the inspections listed above, it is important to see what the car feels like on the road. A well-sorted E30 should feel planted, stable, and above all else, safe while on the road.

Transmission Inspection

One of the first things that you should pay attention to on an E30 test drive is the state of the transmission. Before setting off, it is a good idea to first row through the gears, paying close attention to how smooth each gear engages. It should feel smooth and tight. If shifts are difficult or rough, the car might need new shift bushings or carrier bushings. The clutch should feel firm and even when being depressed and coming back up.

Other Considerations

Once you are on the road, there are a few telltale signs that you should be looking for. While at low speeds, listen for any wheel-bearing noise in the form of squeaks or whistles. Also, listen for any chatter from the power steering pump during sharp turns.

At normal speeds, feel for any bumps or clunking, especially from the rear end. If they are present, it is a pretty good sign that the drivetrain mounts and driveshaft guibo will need to be replaced imminently. 

At higher highway speeds it is important to feel for any violent vibrations or excess bounciness from the suspension. Violent shaking can be caused by a number of things from worn tie rods, failing ball joints, a sticking brake caliper, or an imbalanced wheel. The suspension should feel comfortable too. Factory E30 suspension is actually quite good, so a harsh, or conversely bouncy, ride is emblematic of a suspension setup that needs a refresh. 

Lastly, it is important to check the brakes. It is a good idea to do a 30-40mph to stop test to check the status of the pads and rotors. If the brake pedal immediately goes to the floor under braking, it is a sign that the hydraulic system needs to be inspected. If the E30 pulls to one direction under braking it could mean a stuck caliper or worn suspension components need to be addressed.

E30 Buyers Guide – Summary and Final Notes

For anyone looking for a classic car with unquestionable pedigree and style, the BMW E30 is the answer. Few cars old, or new, can match the feel of an E30 on the road. That fact is what makes it so desirable today, and the reason that E30 prices are climbing on a daily basis. It’s only a matter of time before they become unattainable for the average enthusiast. Now really is the time to buy one. 

It is extremely important to remember that every E30 on the road today is over 30 years old. With any car that age, there are going to be unforeseen issues. If you do end up purchasing one, it is almost necessary to perform some preventative/restorative maintenance before driving it hard. Some common first steps would be to replace the timing belt, thermostat, water pump, cooling hoses, spark plugs, spark plug wires, intake and exhaust gaskets, valve cover gasket, brake pads, and rotors, and change the oil. 

Regardless of what the previous owner says, it is always better to do it yourself so that you have peace of mind knowing that you have a sorted car. The beauty of the E30 chassis is that it was developed right before the automotive tech revolution. They are simple cars and easy to work on and understand. That makes them great cars to learn on and hone your mechanic skills.

Once the initial maintenance and service have been done to ensure that your E30 is solid and sorted, it’ll unquestionably be one of, if not the, best cars that you’ve ever owned.

Hopefully, this E30 buyers guide helped you in finding the right E30 for you. If you liked this article and are interested in content like this, check out our Ultimate M3 Buyers Guide, or our Ultimate E90 Buyers Guide.