johna's automotive blog

BMW 3-Series (E46) 1998-2004 Review

2021-03-27T12:00:00+10:00

Available as a 4-door sedan, 2-door coupe, 2-door convertible, 3-door hatchback and 5-door wagon (320i only).

Early 318i four-cylinder models with M43 (1.9-litre) engines are generally reliable.

Later four-cylinder models with N42 and N46 engines (318i) can suffer from problems with the variable valve timing system, timing chain tensioners, vacuum pumps, and may burn oil due to worn valve stem seals or piston rings.

M52 engine (323i, 328i) can consume oil due to engine wear or PCV system components. M54 engine (320i, 325i, 330i) can have issues with piston rings requiring an expensive engine overhaul.

S52 engine (M3) also suffer from variable valve timing system issues and rod bearing failure can occur, although not as common as later "M" engines.

All engines use timing chains and most models require premium unleaded.

There have been reports of the chassis cracking, particularly on early 6 cylinder models.

Some late model coupes and convertibles had an SMG transmission (a type of semi-automatic transmission). These have proved to be problematic and expensive to repair.

Image credit: OSX, Public domain, via Wikimedia Commons

BMW E46 3 series buyer's guide (Australia)

2020-05-17T12:00:00+10:00

The new 3 series models were introduced from August 1998 with the 318i and 323i arriving first, followed closely by the 328i. Only the 4-door sedan body was offered initially, and E36 hatches, coupes and convertibles were sold alongside the E46 through to 1999/2000.

All models in the 3 series range were now sourced from South Africa instead of Germany.

Eight airbags and stability and traction control were standard equipment.

The 318i was fitted with the M43TU engine, a 1.9-litre four-cylinder engine with a single cam and eight valves. This engine was carried over from the earlier E36 series but received some updates - an extra 100cc in capacity, and balance shafts to make it run smoother. It's not a particularly powerful engine and feels particularly sluggish when fitted with the optional 4-speed conventional automatic transmission rather than the 5-speed manual.

The M43TU is reliable and has a timing chain that is designed to last the life of the engine.

The other models had the M52 engine six-cylinder engine, a twin-cam 24-valve six-cylinder, which was also carried over from the E36 with some changes including extending the variable valve timing system (VANOS) to both inlet and exhaust camshafts, electronic throttle control (with cable backup), and a dual length variable intake manifold. The 323i (2.5-litre) was available with 5-speed manual or 5-speed "Steptronic" auto, but the 328i (2.8-litre) was auto only.

These M52 engines are fairly reliable but can have issues with oil consumption which are often due to PCV system which needs regular maintenance, and issues with the variable valve timing system. The M52TU engine fitted to E46 models had steel cylinder liners instead of the problematic Nikasil coating used on the E36 and other earlier models.

The following year, in 1999, the coupe and convertible models were introduced. The new bodies were six-cylinder only - 323Ci or 328Ci - and all models were available with a manual or automatic gearbox.

A recall affected early models up to June 2000. Many were fitted with Takata airbags that were found to be defective and highly dangerous and are subject to an ongoing recall that commenced in 2019. As no replacement airbags were available, BMW has been buying back cars for market value so there is much less of these early models available on the used car market. It is important to check the recall status of any car that you are interested in buying.

Late 2000 saw the first round of major changes to the 3 series. First came the 330 available in sedan, coupe and convertible with the new M54 3.0-litre six-cylinder engine. Like the 328i sedan, the 330i sedan was available with automatic transmission only, but the coupe and convertible were offered with manual transmission.

A short time later the 323 and 328 models were dropped and new models introduced -- the 320 (2.2-litre) and 325 (2.5-litre), both with the M54 engine.

The M54 engine improved on the M52 with a non-return fuel system, fully electronic throttle (no cable backup), new engine management and a revised intake manifold.

Like the M52, the M54 also had issues with oil consumption if the PCV system was not well maintained, and there are reports of excessive oil consumption due to the low friction piston rings not lasting well.

At the same time, the 318i also received a new 2.0-litre 4-cylinder engine called the N42. The new engine was far more advanced than the previous engine. It has twin camshafts, 16 valves and features BMW's variable valve timing system and variable intake valve lift system (Valvetronic).

Unfortunately, the N42 suffers from several reliability issues including a timing chain tensioner that can cause major damage to the engine, oil leaks and high oil consumption due to worn valve stem seals. Proper servicing is critical for these engines to last.

The 2000 facelift also brought some styling changes including revised front end including new headlights, grille and bumper. Inside there was a new widescreen display for the satellite navigation system.

In 2002 a hatchback body was introduced. The "Compact" model range consisted of 316ti (1.8-litre four-cylinder), 318ti (2.0-litre four-cylinder) and 325ti (2.5-litre six-cylinder). Unlike the previous E36 Compact which used the rear suspension from the old E30 3 series, the E46 Compact shared much of its chassis componentry with the other E46 models.

2002 also saw the first station wagon derivative of the 3 series ever introduced in Australia. The "Touring" was available as 320i only (2.2-litre six-cylinder) with manual or automatic transmission. There was an optional M tech package consisting of an attractive body kit, sports seats and 17" wheels. Manual models are highly sought after and attract a significant price premium.

A semi-automatic 6-speed gearbox known as SMG became available on 330 coupe and convertibles. These gearboxes were criticised for the way they drove and they also suffered reliability issues.

Coupes and convertibles received a facelift in 2003 which comprised new headlights, tail-lights, grille and bumpers.

In 2004 BMW offered Sport versions of all models which included a body kit, sports seats and brushed aluminium trim.

The four-cylinder models switched to the newer N46 engine. There were only minor changes between the old and new engine. The N46 has the same common problems as its predecessor.

The new E90 3 series was released in 2006 replacing the E46.

Common problems

Cooling systems require regular maintenance and overheating can lead to expensive engine damage. Radiators, coolant overflow tanks, water pumps, thermostats and plastic water hoses are common failure items.

Front suspension control arms and bushings, and rear shock mounts will wear out over time.

The E46 chassis has been known to suffer from tears in the metal where the rear subframe mounts to the body. This issue appears to mostly affect early six-cylinder models and is something that should be checked prior to purchase as it may not be economical to repair.

Window regulators commonly fail causing problems with opening and closing of the windows.

Options to look for

Seats: Materials available included cloth, Alcantara (like suede) and leather. Optional sports seats have better lateral support and adjustable under-thigh support. Seats can be manual or electronically controlled.

Steering wheels: many have steering wheel controls.

Sunroof.

Audio/visual: CD, CD stackers, satellite navigation with TV.

Body: M tech body kit.

Wheels: various styles and sizes from 15" to 17".

Longitude & Attitude (Car, UK, September 2000)

2020-05-14T12:00:00+10:00

Magazine article comparing the Volvo V40 T4 to Alfa Romeo 156 V6, Audi A4 1.8T, BMW 328i and Vauxhall Vectra V6 wagons. From Car (UK) magazine, September 2000.

BMW Australia E46 3 Series Range Brochure

2020-05-11T12:00:00+10:00

Australian brochure for the E46 3 series range from November 2000. Covers the 318i, 320i (6 cylinder), 320Ci, 325i, 325Ci, 330i, 330Ci, sedan, coupe and convertibles.

8-page brochure includes brief text on each model, standard and optional equipment, and colours.

BMW Australia, 11/2000, Part No. 8888 1900 420 BMW3560.

Why are people still trying to sell their recalled BMWs?

2019-12-19T12:00:00+10:00

Given that BMW has recalled a significant amount of the late 1990s/early 2000s 3-Series (E46), it surprises us that there are still many for sale.

We decided to do a random check on cars currently for sale to see if any were affected by the Takata airbag recalls.

It didn't take long to find one affected – in fact, it was the first one we checked. We went on to find a significant proportion affected by an early recall relating to passenger airbags that were replaced with temporary parts that BMW need to recheck after January 2019.

We also found some cars that hadn't had the passenger airbag recall done at all and some affected by the more recent driver-side airbag recall.

Because replacement airbags are not available, and it may be 18-months before they are, BMW are offering to buy back affected cars at market value.

It has been hard to find out what BMW is offering but we did hear of one owner who accepted a price of $3,000 for an early 318i, although that involved a little negotiation.

It surprises us that people trying to sell their cars – particularly the cheaper ones like a 2000 323i coupe that is offered for sale at $2,800 and is subject to the recall and a "stop driving immediately" warning – aren't taking advantage of BMW's offer.

Maybe they don't know about the recall, but surely BMW have been in touch with all registered car owners.

Is there money to be made buying affected cars and selling them to BMW we wonder?

BMW E46 engine reliability guide

2014-07-04T12:00:00+10:00

I've been looking at buying an E46 BMW 3 series and have been looking into which engines are reliable and which are not. I'll keep this post updated with any information I find, and welcome any feedback.

M43TU (318i, 1998 to 2001)

The M43TU engine seems to be a reliable choice. It has a timing chain.

Common problems include failure of the mass airflow sensor.

N42B20 (318i, November 2001 to 2005)

Common problems include timing chain jumping teeth usually due to a faulty timing chain tensioner. An updated part is available. This problem has also been known to be caused by a worn or broken timing chain tensioner guide (possibly caused by the faulty tensioner allowing the chain to move around a lot more than intended), which is a plastic part. Look for rattling noise on startup, although it can be difficult to determine.

You can see if the engine is fitted with an updated timing chain tensioner by the size of the tensioner's hex head. The updated design is the new, clean tensioner in the image below.

BMW N42 timing chain tensioners compared

These engines requires regular oil changes using a good quality synthetic oil. Anything less could cause sludging and contribute to the timing chain problem mentioned above.

Other problem areas include ignition coils, crankcase ventilation valve, oil leaks, excessive oil and fuel consumption, and problems with the Valvetronic system.

An Internet search for problems on these engines reveals many discussions and a lot of people have had problems which despite being looked at by various BMW dealers and specialists were difficult and expensive to rectify.

It seems this engine was not one of BMW's most reliable.

M52 (323i and 328i)

Fitted with timing chain and variable valve timing on both inlet and exhaust valves. Aluminium block which means that it doesn't like overheating and head gasket replacement can result in stripped threads. Some oil consumption problems due to either Nikasil cylinder linings, bore glazing or oil separator valve. Many engine blocks were replaced under warranty.

Like most of BMW's VANOS equipped engines, the M52 can suffer problems with this system.

M54 (320i, 325i and 330i)

Has some improvements over its M52 predecessor, but one major issue.

BMW switched to a different type of oil scraper piston ring which may not last long. When these wear out the engine will use a lot of oil. The fix is new rings - either aftermarket or use M52 oil scraper rings.

The other cause of excessive oil consumption is the oil separator, like the M52.

There can also be problems with the VANOS system.

More about flywheel options for BMW M40, M42 and M44 engines

2014-05-21T12:00:00+10:00

As I need to replace the clutch in my supercharged 1998 318is I have been looking into what options there are for a stronger and preferably lighter clutch.

M42/M44 dual mass flywheel and clutch

I presume my car has the original dual mass flywheel and clutch so I could go with just a new clutch kit. However, I have concerns that the flywheel may not be in good condition and it is not advised to have dual-mass flywheels machined so there is a risk to just changing the clutch.

I would also prefer to replace the clutch with one that could handle the extra power from the supercharger better. There are a few choices in stage 1, 2 or 3 clutch kits for M42/M44 powered BMWs on eBay USA which is another option, but again I would prefer to replace the flywheel as well.

M40 solid flywheel and clutch

I looked at the M40 flywheel and clutch kit option, which is a bolt-in replacement and requires only the M40 flywheel and shorter bolts, and an M40 clutch kit. This is a little lighter (1.72 kg) but the clutch is the same diameter (215mm) as the original so is not going to handle the supercharger any better than the original.

I did the M40 flywheel swap on one of my previous 318is's and I can't say I noticed much or possibly any difference in performance or driveability. I did notice a small increase in the amount of vibration and harshness, but really only when at low engine speeds under load, for example when taking off from rest uphill.

Valeo solid flywheel conversion and clutch

Valeo make a solid flywheel conversion kit for the M42/M44 but it is designed as an OE replacement and the flywheel is comparable in weight to the dual mass unit. I can't find any specifications but I presume it is the same size as the original, although one Australian retailer implies it is 235mm (they could not confirm to me if this was true). Assuming it is the same weight and the same size then this seems like an expensive alternative to the M40 flywheel swap. The Valeo part number for the M42/M44 is 52161203.

Update 7 May 2020: I haven't found any official weight but I've read that the Valeo kit is about 5 lbs (2.26kg) lighter than the stock DMF kit.

Clem, who fitted the Valeo kit to his M44, says that the kit includes everything needed including flywheel bolts and is a direct fit. He prefers the more direct and precise feel but says there is some chatter when the air conditioning engages and disengages.

Clem also says, "But the clutch feel IMO is exactly where I like it. Direct and slightly harsher if you don't throttle it correctly. Very precise feel so if you get the throttle wrong for the speed you want to take off it can really mess it up. Clutch chatter is definitely obvious as per the reviews and daily start/stop traffic can really start to annoy if the clutch disengagement vs throttle is not synchronised to the speed of take off."

M20 solid flywheel and clutch

The solid flywheel from the M20 engine, usually the later model E30 325i, seems to be the most popular upgrade. Not only is it lighter (and can be lightened further) but it is also larger (228mm). My issue with this is that it is a more complex swap - you need an M20 flywheel, shorter bolts and an M20 clutch kit. But as the starter/ring gear is different you then either need to swap the ring gear, use an M20 starter (not all fit) or swap some of the M20 starter parts with the M4x starter. Then there's confusion about which throw out bearing to use - the majority say get one from an E21 323i but some say the one that comes with the M20 clutch kit works fine. Lastly you either need to remove some material from the flywheel or remove and fit the spacer from the M4x flywheel (riveted on and needs one hole drilled larger to fit) to stop the M20 flywheel from jamming against some bolts on the back of the engine.

M50/M52/M54/S50 flywheel and clutch

I have read about another option. Apparently, the M50/M52/S50 flywheels and clutches fit too. I have heard that they will only fit E36 models, as the pressure plate is too deep for the E30 gearbox.

There isn't many people talking about this but the ones that are use an aftermarket solid flywheel from an E36 M3 3.0 with the clutch kit from the same model. The advantage is that the clutch diameter is 240mm and obviously designed for the M3 so should be up to extra power of a supercharger. The ring gear is the same so the starter does not need to be changed. One person mentioned they needed to fit the slave cylinder from the M3 too as the original didn't handle the extra pressure. The negatives of this are that the cost of M3 parts is generally much higher (clutch kit is around twice the price).

Apparently all M50/M52/M54 flywheels will bolt straight on without any modifications. All use either a 228 or 240mm diameter clutch plate. Most of the M50/M52/M54 flywheel and clutch combinations weigh around the same as the M42/M44 parts, and some are a little lighter. There is also apparently a conventional flywheel available for the early M50 (E34 525i and E36 320i) without air conditioning although I doubt any of these made it out of Europe and the weight is similar to the dual mass flywheel/clutch combination.

Update: I don't know if the flywheel/clutches from models with the ZF gearbox (eg. 328i) do fit or not. The 228mm flywheel/clutches from the M50 320i/325i and M52 323i, which use a similar Getrag gearbox to the 318is, seem like a safer choice.

Update 1 April 2015: I ended up buying a second-hand flywheel and clutch from an early M50 engine. I paid A$150 and as the clutch plate was in very good condition I decided to use that rather than buying a new clutch kit. I did have to get a new throwout bearing though. You can read more in my post but the M50 parts were a direct replacement and no further changes were needed.

Update 7 May 2020: Salvatore fitted a dual mass flywheel from a M52B28 to his M43TU powered Z3 that has been fitted with a supercharged from a Mercedes SLK230. He said the M52 parts are about 4mm longer but this didn't prove to be a problem. The only issue he mentioned was that the hole for the pin to lock the engine when replacing the timing chain does not line up. The M43 flywheel is 228mm and weighs 19.6kg in total and the M52 is 240mm and is actually lighter at 17.4kg, and Salvatore says it goes a bit better than before.

M43TU dual mass flywheel and clutch

Recently I discovered that the M43TU engine fitted to the E46 318i (and maybe some E36 Compacts) uses a 228mm clutch plate. The earlier M43 engines can use the same clutch and flywheel options as the M40/M42/M44 so there is a good chance the M43TU flywheel will fit the M40/M42/M44 too. The downside is that the flywheel is a dual-mass type so there wouldn't be any weight saving with this swap. I am yet to confirm that it is even possible and there certainly doesn't seem to be any discussion about this online.

RHD Engineering Flywheel (Updated 20 May 2016)

I found a company in Sydney (Australia) that sells a lightweight flywheel for the M42, M44 and M50 engines for a very reasonable price. They say it uses the original M42/M44/M50 starter motor. You use a clutch is for the M20 engines (228mm), including any aftermarket options with a higher clamping force if needed. Weight is 3.2kg (7lb). See RHD Engineering. Shame I didn't know about this before I fitted an M50 flywheel and clutch.

Here is the weights of the various options:

	Flywheel	Clutch Kit	Total	Total (my scales*)
M42/M44 DMF	(P/N 21211223550) 12.25kg	(P/N 21211223571) 5.04kg	17.29kg	16.5 - 17.0kg
M40 SMF	(P/N 11221739315) 9.99kg	(P/N 21211223569) 5.58kg	15.57kg	14.8 - 15.2kg
M43TU DMF	(P/N 21207508409) 12.87kg	(P/N 21217523618) 5.24kg	18.11kg	19.6kg**
M20 SMF	(P/N 11221706573) 8.5kg	(P/N 21211223102) 6.98kg	15.48kg
M50B25 DMF	(P/N 21211223593) 11.134kg	(P/N 21211223546) 5.920kg	17.054kg	18.0kg
M52B28 DMF	(P/N 21211223599) 11.488kg	(P/N 21211223602) 5.600kg	17.088kg	17.4kg**
RHD SMF	(P/N 21211223599) 3.2kg	(P/N 21211223102) 6.98kg***	10.18kg

*My scales is my own measurement using simple bathroom scales.
**Weights provided by Salvatore Pepe
***There are various M20 clutch kits available that vary in weight

I am still investigating the options so will keep this page updated.