1999-2006 BMW 3-series common problems and fixes

This guide covers common problems that are well-known about the E46 chasis BMW 3-series. Easily regarded as one of BMW’s best models, it has its fair share of problems. These common problems can range from a minor annoyance to catastrophically overheating the engine. This guide will start with the most critical things and trickle down into basic stuff that will make your ride more enjoyable.

First and foremost: Pick yourself up a Bentley Manual!
If you are going to do any work on this car, then you need this. This is the most comprehensive repair guide you can get. It is also available in PDF form on their website.

http://www.amazon.com/BMW-Series-E46-Service-Manual/dp/0837616573

My personal favorite places to buy parts:

1. ECS Tuning. *The* best catalog and customer service, hands-down. Shipping can be expensive, OH customers pay taxes.
http://www.ecstuning.com

2. OEM Bimmer Parts. You can trust every last part here. Excellent customer service.
http://www.oembimmerparts.com

3. Pelican Parts.
http://www.pelicanparts.com

4. BMA Parts.
http://www.bmaparts.com

5. RM European
http://www.rmeuropean.com

6. Autohaus AZ
http://www.autohausaz.com

Coolant Expansion Tank

Problem: Expansion tank can catastrophically rupture, creating an immediate overheat condition and loss of all coolant. This tends to happen on cars > 60,000 miles

Solution: Replace expansion tank with updated one.
P/N: 17117573781

Trusted brands: Genuine BMW, Behr

Symptoms: None, replace ASAP if it has not been

Cost: $45-$100

Additional notes:
Automatic Transmission users will need to also purchase a new transmission thermostat, as it fits into the bottom of the expansion tank and tends to break when being removed.
P/N: 17111437362

Water Pump

Problem: Water pump impeller shatters, or bearings leak due to age

Solution: Replace water pump. P/N 11517527910

Symptoms: Wobbling impeller, impeller noise, weep hole leaks

Trusted brands: Genuine BMW, Saleri, Graf, EMP Stewart

Cost: $45-$200

Additional notes:
Many people use this as an opportunity to replace the plastic water pump pulley with a metal one. Due to its large hollow nature, it has been known to crack. Prevent it with this $25 metal one.

http://www.autohausaz.com/search/product.aspx?partnumber=11511730554&utm_source=google&utm_medium=nonpaid&utm_campaign=frooglePN&utm_term=11511730554&gclid=CJul_evS9L0CFe5aMgodFzQAjg

Fuel Pump

Problem: Fuel pump can fail

Solution: Replace fuel pump (very easy, located under back seat).
P/N: 16146766942

Symptoms: Longer starts, no start, car cuts out on freeway, fuel pump does not turn on when key is in 2nd position

Cost: $150-$300

Trusted brands: Genuine BMW, VDO, German Auto Solutions

DISA Valve Flap

Problem: DISA valve flap will break over time, seal will flatten and cause vacuum leaks

Symptoms: P0171, P0174, misfires, poor low-end performance,

Solutions:

1. Replace DISA valve.

Earlier models: ????
325: P/N: 11617544806
330 P/N: 11617544805

Trusted brands: Genuine BMW, Vaico, Dorman

2. Permanently repair DISA valve with a metal valve. Note: does not solve any internal problems with your DISA, if they exist. Test its spring action first before purchasing this kit. Personally I would say just get a new Dorman DISA, it’s about the same price and it’s brand-new.

http://germanautosolutions.com/bmw_solutions/disa_products/m54_m52tu/m54_disa_repair_kit/product_m54_disa_repair_kit.php

3. If only a leak, replace O-Ring.

Note 330 owners: Must scrape off old seal

http://germanautosolutions.com/bmw_solutions/disa_products/m54_m52tu/m54_disa_o_rings/product_m54_disa_o_rings.php

Cost: $10-$300, depending upon the problem

********************************* MORE PENDING *********************************

Gotta go back to work! Will continue later

Edit: Why are all the bolded things in bright orange?