The Definitive BMW E46 3-Series (1999-2006) Suspension Refresh Guide! (Cheapest prices) 1/2015

This guide will provide essential information and part numbers to refresh your non-M E46 suspension.

I realize a lot of people are on budgets so I'll divide this list into three stages in order of most important (failure prone) to least important (more durable).

Stage 1:

Front control arm bushings w/ bracket, part number 31126783376 x 2

Genuine BMW Front Control Arm Bushing Set (With brackets for easy install)


Associated FCAB hardware:

Bracket bolts (four per car), part number 33306760652 x4 (Meyle HD units come w/ new bolts. If Genuine BMW does too, then no need to order new bolts for the brackets)  BMW bushings are great and they maintain the supple yet firm steering feel BMWs are known for.  You can take it a step further in both feedback/feel and durability and get a solid rubber design like Meyle HD.

At 50,000+ miles, these bushings are well on their way out, if not completely expired. Symptoms can and will include play in steering at any speed, click/clunk as you sharply apply the brake, or steering wheel vibration under braking or general looseness in the steering.

Install tips: 

If you're replacing just the bushings, you'll need a gear puller to separate the bushing and bracket from the end of the control arm.  To reinstall, lube up the control arm and bushing with 1 part soap to 20 parts water and firmly tap onto the arm with a rubber mallet.  The end of the control arm should be flush with the end of the bushing. Don't tap on too far and don't tap on too little.  When you reinstall the reinforcement plate, make sure you purchase 8 new bolts. These are designed to be changed every time you reinstall the plate. They shear in the event of a crash. You don't want to compromise these very crucial items.

Reinforcement plate bolts, link to buy:
http://amzn.to/1P7iZQ6


Struts and Shocks

Struts are in front, shocks are in back. If you have 50,000 or more miles on your E46, your Original Equipment (OE) Sachs-Boge Struts and Shocks are severely degraded, if not totally blown out. You won't notice this because your BMW is stiffly sprung and sway-barred.  It will still ride firm, turn sharply, etc.  The struts/shocks are crucial in wheel control. Your directional stability is severely compromised when your struts and shocks are failed.  This will also cause excess and uneven tire wear. The parts listed below are OE Sport Suspension units. (I'll probably edit this list to include ZHP as well)  Keep in mind these part numbers are for OE/OEM units.  Many people, including myself, go aftermarket.  Personally I went with Bilstein.

BMW performance ZHP, Strut left, part number 31312282459
BMW performance ZHP, Strut right, part number  31312282460

Sport suspension 9/01+ Strut left, part number 31316750791
Sport suspension 9/01+ right, part number 31316750792

Associated strut/shock hardware (highly recommended)

Strut mount (2 per car), link to buy: http://amzn.to/1xNV0jV
Bump stop (2 per car), link to buy: http://amzn.to/1y1CF1x

Strut tower reinforcement plates (VITAL--must install! Or you risk bending/distorting the chassis! Especially with stiffer shocks/struts) two per car, link to buy: http://amzn.to/1xNV8Qk

Shocks

Shocks BMW performance ZHP, (2 per car) part number 33522282461 , link to buy: http://amzn.to/1BR2pOF
Shocks sport package, (2 per car) part number 33521096366, link to buy: http://amzn.to/1I5BbYB
Shock mount (2 per car), link to buy: http://amzn.to/14CVkGw


Associated hardware

Bump stop (2 per car), link to buy: http://amzn.to/1xZPGvC
Paper gasket (2 per car), link to buy: http://amzn.to/1y1Dc3B
Shock tower reinforcement plates (2 per car), part number 51718413359 (VITAL--must install!)

If your bump stops are in good condition, you may reuse. If soft, deteriorated, or chunks missing just replace it.  If you go aftermarket Bilstein, they feature internal bump stops. No need for external bump stops.

Install tips:

Perform this work at your own risk. Do not engage in any work that is beyond your comfort and/or skill level.  Always secure car on level ground using quality jackstands.  Use quality jacks to lift car only, not support.

You will need a quality set of spring compressors, a variety of heavy-duty tools such as a breaker bar, heavy duty ratchet, large socket set and an allen key set (I believe you'll need a 6mm allen key to prevent the strut piston from turning as you undo the top nut.)  You'll need a 21 or 22mm socket to undo the top nut. Make sure the socket has a hexed-head on it so you can turn it using a 21 or 22mm open end wrench as you hold the piston stationary using a 6mm allen key. This is self-explanatory as you begin to do the work.  A nice electric or air-powered impact gun can also do the job quite nicely.

For installation and torque specifics, consult TIS or a Bentley owners' manual.

Always reuse all washers in correct orientation.

Always replace suspension components in pairs.

Always replace any hardware that is severely corroded or otherwise compromised or damaged.

Always install quality name-brand parts.

Front swaybar endlinks

Chances are your front swaybar endlinks are torn where the rubber boots hold the grease at the balljoints.  Replace.  Link to buy: http://amzn.to/14CVIoC

Rear swaybar endlinks

Link to buy: http://amzn.to/1DI8ZIA

Install tips:

Both front wheels have to be unloaded before you begin to remove/install these. Use one 16mm socket and ratchet and a 16mm open-ended wrench on the other side to counter hold the bolt as you loosen the nut.  No special tools are needed. These need to be installed TIGHTLY or you WILL hear a clunk or pop while driving over bumps.  I can't stress this enough.

Front swaybar bushings

These definitely need replacing. Worn bushings will compromise the response and stability of side-to-side maneuvering.  Two per car:

23.5mm for 4/01+ vehicles with sport package, part number 33556751269

23mm (non-sport?) part number 31351097179.

Note: I ordered 23.5mm bushings but received 23mm bushings. I installed them without any problems. Slightly tighter fit.

Rear swaybar bushings

Rear: 18mm all sedans 4/01+, non-sport sedans up to 4/01, part number: 33551138104

19mm all sedans with sport suspension up to 4/01, part number: 33551094551

20mm for convertibles, people who have upgraded, and I believe XIs, part number 33551096669

Bonus: 20mm rear swaybar part number 33556751267

Stage 2

Control arms

Theres an inner and outer balljoint.  Typically the outer balljoint fails first and is encased in nylon (less durable) on non-M and non-ZHP models.  It is recommended to replace with ///M ZHP arms or Meyle HD arms.

OEM Lemforder Control Arm Kit (BOTH SIDES) LEFT/RIGHT 

(Don't forget Meyle Control Arm Bushings if yours are worn out)  I've never seen or experienced a failed set. Mine are rock solid after 60,000 miles.

Install tips:

Front of car on jackstands, medium and large pickle forks, plenty of extensions, wobbles, step-down adapters.  Access drivers side control arm inner nut from top and passenger side from down below.

Always buy brand new genuine BMW nuts for the control arms (two per arm) part number, 31106774714 x2, and 32216769539 x2.  Do not skimp on these. Do not use the ones supplied by Meyle.

Tierods (complete assembly)

Self-explanatory.  Any signs of play, damage or leaking of rubber balljoint casing, replace.

Tierod left part number 32211096897
Tierod right part number 32211096898

Tierood boot kit
Two per vehicle, part number 32131096910

Rear trailing arm bushing:

Replace these at 60,000+ miles.  Worn bushings will degrade rear-end stability and basically cause your rear wheels to excessively and unexpectedly to steer.  You'll notice this especially when accelerating from a stop.

Part number 33326770817 (two per vehicle)

Install tips:

Use MIS RTAB tool. Nothing else. Don't even think about it or attempt it.  Use large hose clamp in center of bushing to completely compress the split joint as you begin to press it into the trailing arm. Once in, remove clamp.

Be sure to unclip/unscrew main brake line and associated lines clipped onto the trailing arm.  Have heavy duty breaker bar and torque wrench ready with two 18mm sockets.  Pre-load bushing carrier by aligning the same way it came out. For me the carrier was lined up PERFECTLY with a line naturally casted into the trailing arm. You'll see what I mean when you eyeball it.  Worked like magic.

Get an alignment immediately after. Your toe will be WAY out of spec no matter how much you try to get it lined up perfectly.

Steering Coupler/Flex-Disc/Universal Joint

Part number 32301094703. Apply blue loc-tite when reinstalling the bolts. Make sure threads are cleaned on all bolts and the two splined shafts which the coupler installs on.

Install tips: 

Do this part at the same time as the control arm bushings. The reinforcement plate will have to come off.

Stage 3

**REQUIRED TOOLS**

These require tons of labor and special tools. These are for the pickiest of picky.  You'll need an E36/E46 rear axle service kit which can be found here: http://amzn.to/2dQEm1G

An even CHEAPER axle service kit: http://amzn.to/2dWxqfF

Or unrelated: Fan clutch tool: http://amzn.to/2dWyHTU

Rear end subframe and rear upper/lower, inner/outer control arms bushings and balljoints.

Rear control arms/trailing arm (except main RTAB because it's listed under stage 2)

33326775551 x2
33326771828 x2
33321092247 x2
33326770824 x2

Subframe:

33316770783 x1
33316770784 x1
33316770781 x2


Differential:

33176770788 x2
33176751808 x1

Differential Bushing Bolts:

33176760337 x2 (Two small diff bolts)
33176760336 x1 (One large diff bolt)
33306760349 x1 (Self-locking nut for large diff bolt)

The Definitive BMW E46 3-Series (1999-2006) Maintenance Guide complete with best prices! 1/2015

How does Mango care for his E46?

You just bought your non-M E46 (323/328, 325/330) and you are probably wondering: What do I do now?

Lets start with the basics on how to make sure your E46 is BULLETPROOF for years to come. These are very common failure areas for the E46 and they WILL leave you stranded.  Fortunately, it doesn't cost that much to bring your E46 to roadworthy condition!

Battery - $100-$200

Right off the bat, the first thing I did when I bought my E46 was throw away whatever battery is in the trunk. Unless you have receipts proving the battery is newer than 5 years old, replace it.  A weak battery is known to cause many problems with the electrical systems in the form of cluster lighting up with warning lights to the car randomly doing other electrical-related things.  The most obvious one is your car not starting.  The E46 relies heavily on proper voltage or the electronics tend to be unreliable.  This is one of the few parts you should get at Autozone or Walmart.  Group size 94 or size H8.

E46 Voltage regulator

The voltage regulator is located on the back of the alternator. It regulates voltage to ensure proper operation of the electrical system. Basically by around 6-10 years, they start to fail. This will kill a new battery.  Replace it.This one is a bit tricky because you'll have to pull your alternator out to know which kind you need.  There's a rounded D-shaped connector and squared off rectangle connector. Pray you have the squared off rectangle connector because it's cheaper.  The D-shape connector is found by searching under the BMW Z4.   If you want to buy a rebuilt alternator, check out alternatorpros.com.

E46 Final Stage Resistor $45

This must be replaced. It can drain your battery (killing it permanently no matter how new or old it is) and cause your blower to blow inconsistently or not at all.  Replace it.  Don't be stuck in the summer time with your AC refusing to blow cold air or worse yet a completely dead battery all because you wanted to skimp on $45!

Genuine BMW 5W-30 Engine oil

Mobil 1 0W-40 Engine oil - Approved by Mercedes Benz, Lexus, Porsche, etc. German Specification.

Change your engine oil and filter anywhere between 7,500 and 12,000 miles.  You can likely go up to 15,000 miles without any problems as our cars hold 7 quarts, however for peace of mind, follow the 7,500-12,000 guideline.

Per the BMW owner's manual, you should check the oil level 5 minutes after a hot engine has been shut down. The dipstick is calibrated to read accurately after 5 minutes has passed.

Note: If you track your car, love to drive in a spirited matter, and/or experience lifter tick noise, it is common practice to overfill by one quart for a total of eight quarts.

You should be using oil with a specification ACEA B3/B4 (extended drain/high performance criteria) and/or LL-01.  The following oils are the most readily available proper oil for your car:

Genuine BMW 5W-30
Castrol European Formula 0W-30
Mobil 1 European Formula 0W-40
Pennzoil Ultra 5W-40 European Formula

Genuine BMW-Mann E46 Oil Filters  $5

E46 Oil Filter Housing Gasket  $4

You can use any OE-spec parts store filter in a pinch, but I recommend using Mahle or Mann OE-quality/OEM filters.  Don't skimp here. This is the lifeline of your engine.

Mahle supplies filters to BMWs for their ///M cars.  Mann supplies for non-M.  Both are fine but I prefer Mahle--the quality seems more robust/high-end. Part number:

Spark plugs

Replace every 60,000 miles (BMW says 100,000) NGK BKR6EQUP (6)

Fuel filter, link to buy  $50

OEM Mahle.  If your upper intake boot has an "F" connector with a vacuum line attached, your car has the integrated fuel pressure regulator.  Most E46s come with this. I believe the M56 SULEV  325 cars use the plain in/out filter. Do this every 50,000 miles.

Differential oil, link to buy: http://amzn.to/1wEZi9j

Synthetic 75W-90 gear oil such as Mobil 1 75W-90.  Your non-LSD diff holds approximately 1 quart.  Do this every 50,000 miles

Transmission oil, link to buy (automatic--be sure to check your specific model requirements at your local BMW dealership) http://amzn.to/14CQPvJ or manual: http://amzn.to/1xZNKn1

Automatic Transmission

You should change your automatic transmission fluid and filter with OE or OE-spec'd high-quality fluid every 50-75k miles.  The type and amount of fluid will depend on your year/make/model.  I will list the various types of automatic transmissions and their corresponding fluid:

323i/iS/iC 7/98-3/00, 328i/iS 6/98+ - GM 5L40 (A5S 360R) Texaco ETL 7045E, supercedes ETL 7045, BMW part number: 83220026922

323i/Ci 3/00-8/00, 325i/Ci/Cic 8/00+, 325iT 3/01+, 330i/Ci/Cic 6/00+ - ZF 5HP19 (A5S 325Z), Esso ATF LT 71141, BMW part number: 83229407807

325xi/xiT 8/00+, 325iT 8/00+, 330xi 8/00+ - GM GM5 (A5S 390R), Texaco ETL 8072B, BMW part number: 83220024359

Manual Transmission

BMW MTF-LT-2, or equivalent http://amzn.to/1xZNKn1

Air filters, link to buy: http://amzn.to/1xZNPXK

These should be replaced at roughly every 15,000 miles.  Use Genuine/OEM Mann.  http://amzn.to/1xZNPXK

Cabin air filter, link to buy: http://amzn.to/1I5vhqg

These should be replaced at roughly every 15,000 miles.

Idle Control Valve, link to buy: http://amzn.to/1wF0k5d

Clean every 50,000 miles or replace.  I use SeaFoam Deep Creep: http://amzn.to/1x6rd0D

You might want to replace the rubber grommet which seals it to the intake manifold.  Link to buy: http://amzn.to/1y1A7QV

Clean throttle body

Couldn't find a DIY, but personally I recommend cleaning it.  From the outside (front) mine appeared to be spotless.

The backside was a VERY different story.  Use throttle body cleaner. Requires removal of the airbox, upper and lower intake boots, and electrcial wire junction box.  Four bolts hold it on.  Replace the rubber throttle body gasket.

Throttle body gasket for 323/325/328:  http://amzn.to/14CS1iA

Throttle body gasket for the 330: http://amzn.to/1DI6sOL

DISA Valve

This part can also cause vacuum leaks. It works by altering the volume of the intake manifold depending on engine operation/speed for optimum power and torque under all driving conditions. This system is part of the heart and soul of the BMW M54 powerplant.  Don't skimp here. Remove and inspect yours to ensure the flap is not loose.

You should feel resistance as you manually operate the flap. There should be no excessive noises or rattling.

325/2.5L engines currently use this part: http://amzn.to/14CSmSq

330/3.0L engines currently use this part: http://amzn.to/14cWgAU

323/328 - 2.3L & 2.8L engines appear to currently use this part: http://amzn.to/1BXNkLx


Brake fluid, link to buy: http://amzn.to/1BR04Dj

You should completely replace and bleed your brake system every two years or 25,000 miles or more frequently if you see track use or have overheated your brakes/fluid.  I recommend ATE Super Blue (or amber if you had blue last) :

Some also use Motul for more serious heavy-duty driving.


Valve cover gasket, link to buy: http://amzn.to/1BR09a1

Major source of leaks.  If the front or passenger side (right side) of your engine is covered in oil, then your valve cover gasket is leaking. By 60,000 miles, these are hard, dry, and brittle.  Use Permatex Ultra Black at half moon areas and vanos seams.  LESS IS MORE. Use very little sealant. Don't forget the 15 rubber grommets: part number: [B]11121437395[/B].  Up to 9/02, part number [B]11129070990 [/B]and 9/02+: [B]11120030496[/B].  If you experience repeated leaking, your valve cover could be damaged or warped.

Oil filter housing gasket, link to buy: http://amzn.to/1x6se90

Major source of MAJOR leaks. The left side of the block will be wet and you'll have puddles in your driveway. Replace when leaking.

Vanos line, link to buy: http://amzn.to/1xZODvH

Do this when you replace the oil filter housing gasket.  Link to buy: http://amzn.to/1xZODvH

Also replace four 14x20 copper sealing gaskets, link to buy 4x gaskets: http://amzn.to/1I5xWjW

Power steering

Use ATF Dexron III only.  Replace reservoir as it has integrated filter.  Link to buy reservoir: http://amzn.to/1wF2h1u

Also trim and re-clamp (using new universal clamps) the power steering lines to the bottom of the reservoir and to the return line at the pump. The BMW clamps get loose over time and oil leaks/seeps out.

Exterior/interior

Of course, clean the exterior/interior and engine compartment.  There's nothing worse than a dirty car with an engine compartment full of leaves, debris, oil, spiders, and dead rats. Cleaning also can help reveal problem areas or parts that are leaking.  A clean engine is also more satisfying to work on.

I use the Wagner 915 steamer for my interior, engine compartment, and certain exterior items as well. I can't even begin to tell you how well this works! Great for home too. No need for chemicals (Saves $$!!)

Cooling System Guide (Complete)

http://e46cooling.blogspot.com/2014/10/parts-sources-urlhttpwww.html

These are the absolute bare essentials to have a nice running and decently reliable car.   It doesn't stop here though.

Links or products subject to change.  Research your particular vehicle, part numbers, and/or needs for your application.

Gadget review: Portable 3,300 mAh iPhone or Android, Etc. USB Charger/LED Flashlight Combo -- 17 bucks!

Here's my review of this cool USB charger I found on Amazon.  It's a 3,300 mAh battery inside of a flashlight that can fully charge a cell phone (and have PLENTY of power leftover) as well as act as a VERY bright LED flashlight.  It has two brightness levels and a strobe feature. Completely cool and fits in your pocket, purse, backpack, or glovebox. Perfect for travel! No need to sit at a Starbucks or Airport terminal tethered to a wall.

Here's where to buy: Amazon.com - RavPower Portable Charger/LED Flashlight

The RavPower LED/Portable Phone Charger itself:

Charging the flashlight/charger unit while plugged into a wall with the supplied USB cable (any micro USB cable will work).  You can also charge using a laptop or any USB power source.

Plugged directly into my iPhone 6!

Think you're a pimp? Think again. The appeal of the $5,000 second-hand BMW.

Luxury.  Status.  Quality.  

Many want it, but few are prepared or even willing to really pay for it.

The appeal of the $5,000 second or third-hand BMW has a far and wide reach.  The relative complexity and maintenance costs of these cars is a factor that drives down the entry cost for such cars many years after they've left the factory.  What was once a $35,000+ car in its day, a used BMW E46 can be had a decade later for as little as $5,000.   This puts this timeless and beautiful car--often regarded as one of the best BMWs ever made--dead center in the crosshairs of people who want the status, but who can't, or who aren't willing or able to fork the $45,000 of a brand new BMW 3-Series.

As an owner of one of these fine machines, I definitely understand the appeal of getting more for less.  Why shell out up to $800 a month for a new BMW that has most of the features mine has all while weighing more and having relatively slower reflexes for performance-oriented driving?  This no-brainer value is one of the reasons I bought mine.

These cars are so great that they have a large enthusiast following on internet message boards and car forums.  These are communities chock full of E46 enthusiasts that discuss everything from maintenance, performance modifications, or even their beloved pet beagles.  Among these daily discussions, however, are a steady stream of new and confused owners seeking for help on why their used german automobile is blowing steam or doesn't start, or a myriad of other potential problems.  A common posting is, "HELP! I JUST BOUGHT A USED E46 AND IT WONT START. THIS CAR IS JUNK!"  These new owners often expect their 100,000+ mile, 10-year old BMW to start and drive as reliably and nicely as a brand new one.  They are almost always disappointed when they find out that this isn't the case.

The thing that these new owners sometimes fail to understand is that there will always be a cost to properly drive and operate a new or used german luxury car such as a BMW.  For a BMW bought on the used car market, this cost goes beyond the price of admission.  I've put together a rough list of parts that should be replaced upon purchase of a used BMW E46 3-Series.  That link can be seen here.  This list covers the basics that often fail leaving people stranded causing them to destroy their engines causing permanent damage or become stranded to cost them even more money on towing fees, etc., not to mention the danger of leaving a wife and children stranded.

A $5,000 car doesn't mean $5,000 maintenance.  You cannot expect to drive a 10-year old,  100,000+ mile, once-$40,000 BMW off the lot and expect to look fancy and show up to parties with your newfound status symbol.  These cars require real maintenance real fast!  These are absolutely great cars if they are maintained and they will last you several lifetimes!

So if you bought a used E46 and you just got done reading this blog post, you wonder how much does it cost then?

About $3,000.  This $3,000 in addition to the cost of your car will address the cooling, electrical, fuel, and vacuum systems as well as the basic components of the suspension.  If your budget for a used E46 is $5,000, make sure you've saved $8,000 or close to it.  If you spend $5,000 on your used E46 and just want to drive it and put gas in it, you will have problems rather quickly.  At around 100,000 miles and 10 years is about when things are just about ready to die.  From the plastic parts in the cooling system, to the pulleys and belts, to the fuel delivery systems, and the electrical systems.  Luckily these parts can be had at fractions of the cost online versus your local BMW dealer.

Refresh these cars  with $3,000 in parts every 80,000-100,000 miles or so and you'll never experience a problem in your lifetime.  

Spend a little now, save a lot in the long run.  A properly and decently refreshed used  BMW 3-Series will cost anywhere between $8,000 and $13,000.  Considering a reliable and well-handling BMW E46 is one third to one half the price of a brand new Toyota Corolla, that's a bargain of the century. And you won't be accused of being a poser!

The Definitive Mango BMW E46 Cooling System Blog with Complete Parts list and tips!

PROTECT YOUR E46

This blog post is for you if you just purchased your E46 3-Series and/or have more than 75,000 miles on your current cooling system on your E46 3-Series BMW.

The BMW E46 3-Series is among certain BMW models that are known to to suffer from cooling-related failures, often times catastrophic due to warping the engine block.

The 6-cylinder in your E46 is a straight six design featuring an aluminum head and block.  This design has inherent benefits for which BMW engines are known for.  However this design also has inherent drawbacks.  When overheated even for seconds, the long aluminum head on a BMW straight six is particularly vulnerable to warping.  The fix is a risky and costly top end engine rebuild or a complete engine replacement.  The cost is $3,500 and up.

When a BMW  3-Series overheats, the result is usually a blown headgasket causing coolant consumption, coolant/oil mixing, or an overpressure situation in the cooling system.  Either way, the car will not run long during any of these three conditions.  This happens to so many people on a daily basis but can easily be prevented with $500-750 worth of parts every 75,000 miles.

As such, it is absolutely imperative that you maintain your BMW E36/E46 3-Series cooling system.

If your temperature gauge does go into the red zone, shut off the car immediately and have it towed.

BMW E46 Complete Cooling System List 9-26-16

Mangos Engine including Rebuilt Cooling System

Appreciate your support over the years and using my links--I earn a small amount when you use them and it doesn't affect you at all.  Much love! 

The List.  11-16-17

1) Radiator

(Manual transmission) link to buy

(Automatic transmission) link to buy

2) Expansion Tank

link to buy

3) Expansion Tank Cap

link to buy

4) Water Pump

 link to buy

5) Radiator Hose Lower

link to buy

6) Radiator Hose Upper

link to buy

7) Expansion Tank to Pipe Lower Hose (VERY important)
link to buy

8) Thermostat

link to buy

9) Radiator Fan Switch

link to buy

10) Water Pump Pulley

URO Aluminum link to buy

11) Coolant drain crush washer at engine-block

link to buy

12) Water pump pulley bolts (You can reuse these if you are careful)

link to buy

13) Belt Tensioner Pulley (Main central pulley)

link to buy

14) Alternator Deflector Pulley

link to buy

15) Coolant
link to buy

A/C PULLEYS

See this thread before ordering to make sure which A/C pulley you need. http://www.e46fanatics.com/forum/showthread.php?t=974746 

16) A/C Tensioner Pulley - Mechanical

Dayco 89133 link to buy

Alternative:**Thanks To Terra, you can also buy BMW X5 part for your hydraulic tensioner.  #11287549557  it comes with a backing plate you won't be using. Discard it. Just reuse your bolt**

16) A/C Tensioner Pulley - Hydraulic
link to buy

17) Alternator/accessory belt (Main large drive belt--The same across all model year cars)

link to buy

18) A/C belt (Differs dependent on your build date--see below)

link to buy (5-rib production date up to 9/2002) 

or;

link to buy (4-rib production date from 9/02)

Expansion Tank Mounting Plate Manual Transmission (Optional--You may reuse--For manuals only) link to buy

ATTENTION!!

If your E46 has an automatic transmission, you'll need to add at least some of the following parts to the above list:

Automatic Transmission Expansion Tank Mounting Plate (Again, optional--you may reuse)

Genuine BMW link to buy

Automatic Transmission Thermostat (often crumbles apart upon removal of original--DO NOT GET CAUGHT WITH YOUR PANTS DOWN ON THIS--REQUIRED FOR AUTOMATICS)

Genuine BMW link to buy

Automatic Transmission Fan blade (Optional yet recommended)

Genuine BMW link to buy

Automatic Transmission Fan Clutch (Optional yet recommended)

HELLA link to buy

Automatic Transmission Cooler O-Rings. (Highly recommended as the old ones tend to not seal the same) Order two of these for the transmission cooler.
OEM link to buy

Prices, information, and brands/prices/links subject to change. These are current as of 9-25-16

The total cost for manual cars is around $500. For automatic cars, around $750 which includes the fan blade/clutch.

The failures:

How, why, and when do the failures typically occur?

Expansion Tank

The number one cause of cooling failure for the E46 3-Series is the expansion tank.  This tank has a 100% failure rate and fails on every single E46, usually around or before 90,000 miles.  This can be installed in your driveway in 45 minutes or less using simple hand tools.  If you can change a light bulb, you can change your expansion tank.

Some fail sooner than that while some last longer.  These tanks fail because of heat cycling of the plastic material they are made of.   Typically the failure will make itself known when you see a yellow low coolant light on your gauge cluster.  You will open the hood and the tank will look fine but what you don't see is the hairline crack that formed down the side of it, usually invisible to the naked eye.  This crack expands under pressure and water spews out either while driving or when the car is parked.  Come back to your E46 and there's a puddle under it? Yep that's your expansion take 9/10 times.   If the water/coolant level becomes low enough, there will not be enough coolant for the water pump to circulate.  No circulation means no flow through the engine/radiator. No flow through the radiator/engine means overheating and a $5,000 engine replacement and lost down time, towing fees, rental car fees, headaches, etc. Again, buy here.  DO NOT BUY THIS AFTERMARKET IF OU CAN AVOID IT.  GENUINE BMW ONLY.  Genuine BMW is maybe $20 more but it's worth it.  If you do not buy Genuine BMW, you may buy OEM which as of time of writing, is the brand CoolXpert.

If you just need the expansion tank cap, buy here. It's good to keep a spare cap or replace at 25,000 mile intervals because the seals on the cap are known to harden and lose their ability to seal, even between tank replacements.  They're around $12 -- good investment.

Pulleys and belt(s) systems 

Our M5X and S54 engines have three belt-driven tensioner pulleys. The role of the tensioner is either to provide belt-spacing/traction and to quell crankshaft vibrations due to irregular accelerations from the crankshaft. This is done to prolong the life of belt-driven accessories and likely to quiet engine operation.

When should you replace your pulleys?

If your pulleys are original: replace them.

If you don't know how old they are: replace them.

If they are noisy or have excess play: replace them.

If they have 60,000 or more miles: replace them.

This is a crude diagram of the front of an M5X engine: 

The main belt drives the water pump, alternator, and power steering pump.  This belt is guided by pulleys.  These pulleys contain ball bearings and grease.  After around 60k miles, this grease dries up and the pulleys are vulnerable to failure.  The belts are then thrown off once this pulley fails and you now have no cooling system, no power steering, and no charging system.Your dashboard will light up like a christmas tree and your temp needle will fly into the red zone.

Belts.  Obviously the belts themselves can fail causing an otherwise brand new cooling system to not operate. Replace every 35k miles. You can find it here.

This belt system is no joke.  E46s are prone to pulley failure.  I've seen it time and time again.  Is your E46 squealing and whistling?  Replace your pulleys. They're cheap and very easy to replace.

See my thread here for more info and discussion: http://www.e46fanatics.com/forum/showthread.php?t=974746

Water Pump

The water pump is another potential failure point but admittedly not as common.   It can fail in at least three ways. 1) The impellar itself will break and cannot continue to push water.  2) The seal may leak and, 3) The bearings will fail causing the shaft to wobble and break which will in turn throw the belts off effectively rendering your cooling system useless.

You might hear nightmares of water pumps with plastic impellars, but don't pay attention to this.  Replace your water pump due to age and/or mileage, not because what its made out of.  The latest BMW water pump design (at least 10-15 years old) features a plastic composite impellar.  BMW did once try metal impellars but quickly phased those out due to premature balancing and bearing failures.  Design is more important than physical materials.  Some people insist on installing the Stewart water pump.  Some recent reports suggest that these are low-volume production items and may fail prematurely. Others report success.  It's up to you.  If you insist on the Stewart water pump, it can be found here.

You'll need to remove the fan on your automatic E46 to access the water pump. I recommend this fan clutch tool here: http://amzn.to/2dWyHTU

Thermostat

Generally fails in the open position leading to a "cold" temperature needle on your gauge not allowing the car to warm up, this item can leak as well or worse yet, fail closed or partially closed.  It's a good idea to replace it.  Thermostat can be found here.

Radiator 

The E46 radiator is typically robust, but the end tank seals are rubber and harden over time. You'll notice staining or slight weeping.  The radiator has thin passages which can become clogged with sediments as well and may cause water to flow slowly to where it needs to go. This may cause problems in traffic or while stopped.  The plastic end tanks may also fail but this isn't that common of a failure mode for this part.  They are cheap enough to replace anyway and is one of the most vital cooling parts--arguably the most important one.  Don't skimp on this.   Manual Trans unit here and Auto Trans unit here.

Fan blade and clutch

(for automatic transmission equipped vehicles).

Another failure point.  If the blade chips or deteriorates, there goes its balance and will explode in your engine bay.  There goes your belts, hoses, hood and whatever else it feels like taking out.  The fan clutch is typically robust, but is good practice to replace it anyway.  It controls the speed of the fan. You don't want it spinning too slowly or too quickly. A fan that cannot blow sufficient air over the radiator will fail to cool the water/coolant and thus the car will overheat. This typically happens when the car is stopped in traffic, say at a red light.

BONUS - WHY IS YOUR E46 OVERHEATING?

Written specifically by Mango

In order for your car to not overheat, these basic requirements have to be met:

1) Cooling system must be filled to capacity. That is to say the system must have no leaks and no air bubbles or pockets in it. Car must have correct amount of coolant/water.

2) Water must be able to be driven without any unnatural hindrance. That is to say the water pump must be able to push water throughout the system without added blockages or weakened drive force due to a damaged water pump or slipping/missing belt. The thermostat should also be opening and closing as designed.

3) Air must pass over the radiator in sufficient quantity at the correct moment. That is to say your mechanical and/or electrical-driven fans must be operating correctly when triggered by properly working sensors.

If your car is overheating, at least one of the above is not being met or you have bigger problems with the headgasket (unlikely if you've never overheated before)

If your car is overheating at idle (say in traffic) and you are sure that 1) you have adequate water in the system and 2) said water is air pocket/bubble free, then air is failing to blow over the radiator. You need to investigate why. Either the fan(s) aren't operating properly (not blowing air or enough air) or your fan switch isn't telling the fan to turn on. (or both) Or you have debris between your radiator and condenser. Time to break out the a toothbrush and garden hose.  Remember you must have proper coolant/water flow and proper air flow!! You need both.

COOLING SYSTEM INSTALL TIPS:

Bleeding the system: (VERY IMPORTANT-DANGER DO NOT SKIP!!)

This step is extremely important. No amount of brand new cooling parts in the world will work if you do not bleed the system properly.  The point of bleeding is to remove air bubbles/pockets.  The cooling system is most efficient when it is circulating only fluid. Heat cannot radiate away from the surface of the radiator if there's air pockets.  You are essentially reducing the size of your radiator significantly if you have air pockets running through it.

Here is the official procedure per BMW TIS:

Here is a quick cheat sheet on how to bleed the BMW E46 Cooling System:

Raise front of car on ramps (Not necessary, but recommended)

CAUTION: ONLY DO THIS WHEN CAR IS COOL AND ENGINE IS OFF. At no point should the engine be turned on.

1) Remove expansion tank cap and bleed screw and set aside

2) Turn ignition to ON (dash lights on but do NOT start the car)

3) Set heat to MAXIMUM (90) and fan speed to low (this opens heater valve)

4) Begin to fill your expansion tank with ideally a 50/50 mix of Genuine BMW coolant and distilled water (do not use anything else--no reason to.  The proper stuff is cheap)  The system might take a while to swallow the water.  Massage the hoses if you think it will help.  Keep pouring.  Water will begin to pour out of the bleed screw hole with air bubbles.  The point is to keep filling and filling until the bubbles are gone.  This may take a while--be patient.

5) Once you are satisfied that a continual stream of bubble-free water is emerging from the bleed hole and that your cooling system is adequately filled, go ahead and replace the bleed screw (do not overtighten).  The expansion tank will be full to the top at this point so you'll need to siphon off any excess so that the appropriate tank level can be achieved.

Congratulations! Your E46 is now ready for another 75k miles of trouble-free driving.  Never will you have to worry about being stranded with your wife, girlfriend, pets or kids in the car.  Never will you have to worry about posting a thread asking why your car is overheating or why your engine is stained with coolant. Never again will you have to worry. (at least for another 75k miles) :thumbsup:  The mileage is just a guide. Your results may vary.

Happy motoring
-Mango

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