Friday, January 9, 2015

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

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:

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) or manual:

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

Air filters, link to buy:

These should be replaced at roughly every 15,000 miles.  Use Genuine/OEM Mann.

Cabin air filter, link to buy:

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

Idle Control Valve, link to buy:

Clean every 50,000 miles or replace.  I use SeaFoam Deep Creep:

You might want to replace the rubber grommet which seals it to the intake manifold.  Link to buy:

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:

Throttle body gasket for the 330:

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:

330/3.0L engines currently use this part:

323/328 - 2.3L & 2.8L engines appear to currently use this part:

Brake fluid, link to buy:

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:

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:

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:

Do this when you replace the oil filter housing gasket.  Link to buy:

Also replace four 14x20 copper sealing gaskets, link to buy 4x gaskets:

Power steering

Use ATF Dexron III only.  Replace reservoir as it has integrated filter.  Link to buy reservoir:

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.


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)

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.

1 comment:

  1. Thanks for the awesome articles! I just bought a used 2002 330xi for $3100 and it has 154,000 miles. The previous owner looked to have maintained it relatively well but I am taking your recommendations and, without documentation in hand, replacing many of the components you talk about.

    So far I have replaced all the filters, oil changed, oil pressure sensor, oil level sensor, O2 sensors cleaned (might replace them later), the valve cover gasket (found oil on the block passenger side) and the windshield cowling which was falling apart. My next challenge is replacing the clutch/flywheel, main rear seal, transmission seals (manual), and the shifter detent pins including the shifter bearings.
    The cooling system seems fine but I will definitely replace the expansion tank and thermostat ASAP and possibly the radiator although I might wait until next spring for that.
    One of the control arms are and so both are ordered and finally the front struts are overdue for replacement. She still drives great and I am confident that through the summer as I replace small things she should be ready for the next 150,000 miles!

    Thanks for the great articles. Are there any items unique to the xi series that might need consideration like the transfer case? What are your thoughts?




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