Top 10 Parts to Fail on your E46

Top 10 E46 Failures

These 10 parts will certainly fail on you

The BMW E46 3-Series produced from 2000 to 2006 is one of the more reliable BMWs you can buy.  You may have read my widely distributed and viewed post on the BMW E46 Cooling System detailing the common failures and the catastrophic results a single failure can result in, or you may have read my other posts on E46Fanatics.com which recommend full system replacements rather than picking, choosing, and replacing each individual part as they fail. I highly recommend you check out those threads including the links in my signature.

Check out Mango's E-Store =) http://astore.amazon.com/e46acc-20

However I realize not everyone can afford to replace $3,000 worth of parts to restore their BMW E46 3-Series back to reliable and well handling condition.  So I've created a top 10 list of must-replace items for your BMW E46 3-Series.  These parts are the 10 failures of the E46 platform and are certain to leave you stranded, frustrated, or leave your car with dangerous sloppy handling.

Number One - Expansion Tank

While I still recommend full replacement of the E46 cooling system, the expansion tank is an absolute must.  It is not optional and it should 100% absolutely be replaced upon your purchase of an E46.  Do NOT skimp on this.  The common failure is for the tank to develop a hairline crack down the side of the tank resulting in a low coolant light and shortly (seconds) after that, an engine overheat which will destroy your soft aluminum engine in mere seconds.  Many have been in big trouble because they've neglected to replace this $60 part.  You can also buy the E46 Expansion Tank here on Amazon.  The links are to OEM expansion tanks.  Do not buy this part aftermarket.

Number Two - A/C Blower Final Stage Resistor

This part fails on ALL BMW E46s.  And E36s for that matter.  The BMW E46 Final Stage Resistor is responsible for your A/C Blower Fan speed.  The failure is erratic fan speed behavior or the fan completely failing to turn on.  This is torture on a hot summer day.  This failed part has also been known to cause car fires.  Very dangerous.  

Number Three - Fuel Pump

Experiencing long cranks? Hard starts?  Does your engine just crank and crank but doesn't turn over? If you haven't experienced any of these symptoms, you will.  This failure will happen. Replace the fuel pump on your BMW E46 every 60k miles or 5 years for maximum protection from being stranded.  Some go longer, others aren't so fortunate. Luckily it's extremely easy and cheap to replace. Pull up rear seat and voila.  Right there.  Don't forget the seal.  Buy the pump here on Amazon.

Number Four - Throttle Body Intake Boots

Very common failure.  The boots that connect your air filter box to your throttle body dry out and crack over the years.  Will cause vacuum leaks.  The symptom is poor fuel mileage and/or stumbling, idling problems and stalling.  Replace your upper and lower intake boots.  Cheap stuff. Don't skimp.  Make sure you align the tab on the lower boot with the space on the throttle body.  Very easy install.
325i/323i/328i lower boot: http://amzn.to/2d4fv8s  and the upper boot: http://amzn.to/2dukMEr
and 330i lower boot: http://amzn.to/2dlUTKj and upper boot: http://amzn.to/2dmSP0y

Don't forget the throttle body sealing ring:

323/325/328 models: http://amzn.to/2dlVBas
330 models: http://amzn.to/2d1aK1S

Double check your model's part #s before ordering.

I read that the M56 powered BMW 3-Series uses the 330 boots. Check to make sure. 

Number Five - Crankcase Vent System

The BMW E46 Crankcase Ventiliation Kit will certainly fall causing a vacuum leak.  Poor idling, stumbling, poor fuel mileage.  Rubber and plastic cracks and fails over time.  Replace it once and never touch it again.  I recommend Genuine BMW but the above linked kit is available at a fraction of the price.

Bonus: Don't forget to replace the vacuum tubing that connects to the F connector to semi-hard line that goes to the fuel filter.  

Info credit to HodgkinsC330i: Hose diameter: 5/32", available from O'Reilly part# P3340: $3.49 - Product Description: Thermoid Windshield Washer & Vacuum Tubing 5/32" x 6'

Post here showing diagrams of the system (see post #6): http://www.bimmerfest.com/forums/sho...d.php?t=574814

Number Six - Control Arm Bushings

The rubber in your front control arm bushings rot over time and will cause sloppy and loose steering/handling.  If totally failed, your suspension will clunk as you brake and your entire front wheel will move forward 1 to 2 inches -- very dangerous at highway speeds.  If you can't brake, you may crash.  Easy install, two bolts hold it on.  Get a 3-jaw puller and pull the old one off.  Spray windex or soapy water on the new bushing and tap it on with a rubber mallet.  Torque it down and enjoy your new handling. Buy them here on Amazon.

Number Seven - Rear Trailing Arm Bushings (RTABs)

Same as above.  These rot out and cause sloppy rear handling.  Replace every 50,000 miles or 35,000 miles if you are really picky.  These are responsible for rear wheel toe control.  Give your car gas and if the rear end wags under acceleration, your bushings are toast.  Very dangerous if they fail. Buy here at Amazon.  

Bonus: I recommend M3 rear trailing arm bushings as an upgrade for more solid handling.  Direct fit. Plug and play. This kit comes with the famous shims for even greater control.

If you want to do these yourself, I recommend an RTAB tool.  You can also search Google for an "MIS RTAB tool."

Number Eight - Alternator or Voltage Regulator

Battery light flickering? Constant dead batteries?  Even if you don't experience those symptoms, you will.  It's usually the voltage regulator that fails, but many just replace the alternator which will include a new voltage regulator (it's bolted to it.)  Many figure "why not?"  You can also just replace the voltage regulator here for $40 -- this is surely to leave you stranded one day as the brushes on the regulator wear down! It bolts on the back of the alternator using a screw driver.  Make sure you look at yours closely and see what plug it uses. The one I linked is the square plug. Usually the one installed on most E46s.  

MAKE SURE YOU GO LOOK AT YOUR CAR TO SEE WHAT CONNECTOR YOU HAVE. SQUARE OR ROUND?  Also install the same or higher amperage as what your car came with.  

More common square plug alternator for 325 and 330: https://www.fcpeuro.com/products/bmw-alternator-90-amp-e46-x5-z3-al9405x

Less common round plug alternator for 325 and 330: https://www.fcpeuro.com/products/bmw-alternator-z4-al0816x

323/328 square 3-pin alternator: https://www.fcpeuro.com/products/bmw-alternator-323i-328ci-328i-528i-z3-al0738x

Number Nine - Pulleys and Belts

These pulleys carry your belt system and will dry out and rot over time.  Do your pulleys sound like skateboard wheels when spun?  Does your engine make a squeaky noise as it runs?  Your pulleys are ready to fail. When they do, it will throw the belts off and take your engine down with it. Instant overheat. Instant engine rebuild.  Don't risk it.  Don't forget to get new belts. You may as well.

See my thread here for what parts you need and where to buy them: http://www.e46fanatics.com/forum/showthread.php?t=974746

Number Ten - Battery - Autozone H8 DLG

Very simple.  Replace with a battery from your local parts store. Personally I went with Autozone brand -- paid $200 for my battery.  You may be able to find it for $150.

BONUS - STARTER

Prevent yourself from being stranded when you need to go to work -- or worse yet when in gang territory. This part is known to suddenly and unexpectedly stop working.  Get it here

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Appreciate the support using my links. I earn a small portion when you use them. 

Inquiries: e46mango@gmail.com

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.

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!