Common Problems with the E39 BMW 5-series (525i, 528i, 530i, 540i)

In terms of parts sales, a huge chunk of our BMW surprisingly (or not so much) ends up on an E39 BMW 5-series.  Built between 1995 and 2004 in the wonderfully pronounceable Dingolfing, Germany, this generation was a worthy successor to the very good E34, and was available in Sedan and Wagon with a variety of trims and engines.  This will be a generalized post, so if you come up with something that YOU’VE come across, don’t hesitate to leave a comment below to help anyone that stumbles upon this post while potentially shopping for a car, or diagnosing one they already have.  I am going to focus on the most common 6 cylinder M52 and M54 engines.  Here are some of the top problems that we’ve seen for the BMW E39 5-series cars.

E39 BMW 5-series Cooling System Parts

As with most BMW’s (for reasons we don’t particularly understand), the cooling system is one of the biggest weak points of the E39 BMW 5-Series.  Radiators crack, expansion tanks leak, thermostat housings deform, water pumps and cooling fans explode, fan clutches seize.  It’s a mess, but luckily with a little money and a weekend day you can postpone any cooling system problems before they happen.  Here are the parts you would need to bulletproof your E39 and avoid being stuck on the side of the road like so many sad drivers before you.

Before starting below, be sure to check out our ultimate cooling kit that replaces all common failure points in the E39 525, 528, and 530 cooling system, including hardware.

Radiator – The OEM factory radiators are Behr, while Nissens (an OES for other carmakers) is the same quality for a little less money.  All Aluminum options are nil, but rest easy as the OE aluminum units usually last around 80-100k miles before failure. [see parts]

Water Pump – The E39 BMW 5-Series came with a composite impeller water pump, many customers go with an upgraded metal impeller pump to reduce the likelihood of failure. Pair with an aluminum pulley as the pump does not come with a pulley and the stock plastic pulley tends to age poorly. [see pump] [see aluminum pulley]

Thermostat housing – on this car the thermostat housing also comes with a new thermostat and sensor, an important thing to always change when doing cooling system work. The Behr part is the same as Genuine BMW

Coolant level sensor – a common area for leaks, being at the BOTTOM of the expansion tank, this level sensor should always be replaced alongside the expansion tank.

Expansion tank – Made completely out of plastic, and with several moving parts inside, it is recommended to replace this common weak point before it’s too late.  The Behr part is the same as Genuine BMW

Radiator Fan Sensor – Like the thermostat, whenever doing cooling system service it’s not a bad idea to change the coolant temp sensor.  It’s easy to do, inexpensive, and a bad one can cause severe issues with the way your car runs.  There are two, one that controls the radiator fan and the other that sends signals to the ECU and temperature gauge.  The electronic ECU sensor is far more difficult to change as it is located in the cylinder head instead of on the hose. [see part]

Radiator Hoses – When replacing things like the radiator, thermostat, water pump etc, new hoses are always a good idea.  Old ones become spongy and can rupture, emptying all your coolant in seconds.  We have upper and lower hoses, of course.

Radiator fan and fan clutch – The fan clutch goes through a lot of stress throughout its life and will go bad when the car reaches its midlife crisis (that’s when you get BMW M wheels), when bulletproofing your cooling system the fan clutch should be replaced, along with the fan itself.  The fan is a plastic unit that gets brittle with age and head cycling.  If the fan clutch is wearing out and getting jerky, it can cause the fan to explode in spectacular fashion, inevitably puncturing the radiator and potentially destroying the fan shroud as well.

Coolant – We proudly carry ROWE, which is made in Germany and fits all the exact same specs at a lower price than Genuine.  We also carry Genuine BMW coolant for a great price.

E39 BMW 5-series Thrust Arm Bushings

The front suspension on E39’s is designed to be the best in the business.  Part of this design has a special type of upper control arm called a thrust arm.  Also called a tension arm, this control arm effectively reinforces the geometry of the front wheels, specifically under braking.  Imagine it like the cross stay on a truss going towards the front of the car.  Liquid filled from the factory, the bushings in the thrust arm are notorious for going bad.  You do not want this, specifically because when the wheel has an inch and a half of forward and backward play, the geometry gets really sketchy under braking.  I’m talking about “toe steer”, and it can cause the car to dart from side to side when you want it to be the most stable.  We have several replacement options, including a Powerflex bushing set that carries a lifetime warranty, guaranteeing trouble free braking for the life of the car. [see parts]

E39 BMW 5-series Rear Ball Joints

Kind of like the thrust arm bushings, the rear ball joints take a ton of abuse, even with just normal driving.  This is because the geometry on the rear of the car (unlike many other vehicles in the same class) is designed in a way to eliminate changes in alignment, specifically toe, under load.  To achieve this required a ball joint rather than a bushing, and most cars nearing 100k miles will need these replaced.  When this ball joint is bad, you can hear clunks, feel the rear of the car wander, and occasionally squeaks as well.

E39 BMW 5-series VANOS Seals

The VANOS system on the M50, M52 (single VANOS) and M52TU, M54 (double VANOS) is a variable cam system that is driven by oil pressure. You can read more about how it works here.  It is reported that the seals in the sliding pistons within the VANOS unit go bad from being manufactured with the wrong material.  When the seal goes bad, the hydraulics cease to function and you have a broken VANOS, which will make your BMW E39 5-series run terrible.  It’s important to think about these seals and these units when you are encountering a poorly running engine and check engine lights in reference to a VANOS jam, P1519 among others.  We are working on getting an inexpensive solution to replace these seals.

E39 BMW 5-series V8 Valley Pan

This specifically applies to the V8 guys out there, and not just the 5-series.  The M60 and M62 V8 engine went in a few different chassis but they all have an issue with a seal between the cylinder heads.  Commonly referred to as the valley, there’s a pan that covers a fairly large coolant passage that travels from the back of the block to the front.  This cover came from the factory with a rather ineffective gasket, and when it starts to age coolant will seep past the seal and pool up on top of the valley pan cover.  If you notice a good sized antifreeze coolant leak coming from this area (it will smell like sweet syrup), you’re in for a big job.  The manifold needs to come off, but luckily we carry a replacement cover that has a molded rubber gasket set in it.  This redesign keeps the valley pan sealed and leak free for the rest of the life of the car. [see part]

Front Struts

For whatever reason, most likely due to the strange geometry of the front suspension mentioned above, when the front struts go bad things go haywire.  Manifesting as an occasional violent shutter under braking, the front wheels get caught in a vertical oscillation resulting in significant loss in braking power in some situations. Many E39 drivers have encountered this, and it’s not something to take lightly.  We offer a variety of choices for customers looking to replace their E39 suspension, including OE Sachs (what came on the car from the factory), KYB, Koni, Bilstein, and Genuine BMW.  In addition, eEuroparts builds struts.  That means if you are a DIY’er, but you don’t want to go through the process of utilizing the dangerous spring compressors needed to assemble a strut, we can do it for you!  We have a few struts for the E39, but if you need a set of front struts that we don’t have listed on the website contact customer service.  We can get a strut assembly built for you in just a few short days so you can get it, install it, and enjoy it quickly.

E39 BMW 5-series DISA Valve/blend motor

Described in more detail in this blog article, the Intake Manifold Adjusting Unit, also known as the DISA valve, came on many E39 cars with M52 and M54 6cyl engines.  Basically this is a plastic valve in your intake manifold that diverts air around separate passageways to improve power throughout the rev range and flattening out the torque curve.  When they go bad, they will rattle and cause sluggish acceleration, bad idle, and hesitation.  When they go REALLY bad, the flap can completely break apart and send chunks into your engine.  We’d call that a catastrophic and this happens from time to time.  If you have a high mileage car and have never changed this, it is time.  Preemptively changing the DISA valve will rule out the possibility of breaking down in the future.

E39 BMW 5-series Window Regulator

It’s quite common to get into your E39 on a nice day, go to crack the window, and get a few different results.  The first is the best, everything works fine and the window goes down.  Sometimes it doesn’t play out like that.  The window can get stuck, come off the track, or fall down into the door.  That’s a failed window regulator, which you should replace asap to avoid letting moisture into the car among other things.  The stock E39 BMW 5-Series window regulator is a little flimsy and has a few failure points.  eEuroparts caries a URO Premium unit that carries a lifetime warranty, and that’s because they build their window regulators with ball bearing pulleys, instead of the stock ones which are just plastic sleeves.  Important note, be sure to thoroughly reseal the vapor barrier (the thin foam sheet that you have to remove to get in the door), or else you risk letting water in that will cause major problems for you years down the road. [see parts]

E39 BMW 5-series Headlight Adjustment Mechanism

If you have halogen headlights and feel like they are pointed way too low, you are not alone.  E39 BMW 5-series cars equipped with halogen headlights feature a pair of adjustment screws located on each assembly that control the horizontal and vertical aiming.  Made of kind of squishy plastic, these adjustment screws twist off or break, letting your low beam dip straight to the ground.  There are kits to allow you to replace the screw, but they all require you to take the headlight apart by baking it, melting the glue, taking the mechanism out, finding an aftermarket solution, and then gluing it all back together with an airtight seal.  This is not a project for the faint of heart, and although you will save some money expect to spend a weekend day on a project like this.  Alternatively, you can replace the headlights with brand new ones at eEuroparts.com and enjoy perfect headlights on your car once again. [see parts]

E39 BMW 5-series Ignition Switch

There are few things scarier than an aging BMW that is starting to have strange electrical problems.  Warning lights coming on and off, seats or steering wheel moving like they are haunted, radio malfunctions, climate control funniness.  You don’t have to take your car in for an excorism (yet), many other e39 owners have encountered similar problems and fixed them with a new ignition switch.  We sell a ton of these, so this happens quite a bit.  The switch itself is not too expensive or difficult to remove, so if your E39 BMW 5-Series is acting like it’s haunted, chances are a new switch will cure it.  eEuroparts.com carries the E39 ignition switch in a few different brands, we recommend the Made In Germany Febi unit or the Genuine BMW part.  To replace, you have to remove the black plastic clamshell around the steering wheel, the switch is held in underneath with a few screws.

Bonus Round

Even with the common stuff out of the way, like any car you will have to replace other parts as time goes on.  Luckily we have nearly everything you could ever need or want for your E39 BMW 5-series, from brake kits to oil changes, side mirror covers to alternators, head gaskets to air filters.  Hit the jump below to put your specific E39 BMW 5-series into the vehicle selector and start shopping for things to get your fine German executive car up to full speed in the luxury you deserve.

[Shop E39 BMW 5-series parts]