If you’re a new E46 M3 owner, welcome to the community. If you already have one, keep it! The E46 M3 is honestly not that hard to take care of. There are a few major things you should always keep an eye on and those are outlined in the Mandatory section at the bottom of this article, but otherwise it’s easy. Not too expensive either. This is a 20+ year old car now and parts are available or cheap. So check out this article to know all you need to know about the E46 M3 when it comes to maintenance.

On-Board Computer

The OBC mileage is displayed when you first start your car (or alternate your OBC display via steering toggle) and it’ll say “Inspection” or “Oil Service” followed by a number. Yes, this number can go negative and that means you’re overdue. The highest value it’ll display is 15,500 and it’ll count down as you drive. This is how you gauge when your service is due and BMW technicians will go off this number and your overall odometer reading to determine which service you need whether it’s oil service, safety service, Inspection I, and Inspection II.

However, this schedule allows for a oil change interval every 7,750 miles, which is not what I like to follow. I and most enthusiasts like to do more frequent oil changes at every 5,000 miles, especially if you drive your car hard or track it. Therefore, my personal scheduled maintenance is a little different from BMW’s recommended. Don’t worry. For the 90% of drivers out there, a 7,750 mile oil change interval should be fine as tested by BMW engineers, but for the rest, we’re especially picky.

Since I’m setting my own intervals for oil change, I’m using the OBC purely as estimation for Inspection I and II services. I say “estimation” because depending on how hard you drive your car, the OBC will calculate mileage. OBC is variable as odometer is a fixed mileage reading.

How to Reset OBC

1. Turn off ignition.
2. Hold Trip Reset while turning ignition key to on position.
3. Hold button until one of the following words appear in the display: OIL SERVICE/INSPECTION and RESET.
4. The service due is shown with RESET if the minimum consumption limit has been reached.
5. Press and hold the RESET button again until the word RESET begins to flash.
6. While the display is flashing, press the left button briefly to reset the service interval.
7. You should now see END SIA. Bimmerzone for the maintenance I and II information.

E46 M3 Maintenance: Basic

Oil change is done every 5,000 miles. The first BMW Inspection I Service comes in at 30,000 miles and every 60,000 miles after that. BMW Inspection II Service starts at 60,000 miles and every 60,000 miles after that. Here is my maintenance schedule laid out for the first 120,000 (odometer) miles of ownership.

Inspection I

There are two main Inspection routines that you should follow for preventative E46 M3 maintenance. The BMW Inspection I Service is the smaller of the two inspection services recommended by BMW and it includes changing oil, fluids, etc. I prefer to use Liqui Moly products for all my fluids not only because price is cheaper, but they work amazing. Countless Blackstone Labs tested oil sample reports observed and no “grinding” differential that people experience. I am not endorsed by Liqui Moly. Just love what they make.

Visual Inspections

Undercarriage

• Check transmission for leaks.
• Check rear axle for leaks. Visually check fuel tank, lines, and connections for leaks.
• Check condition, position, and mounting of exhaust system. Examine for leaks.
• Check power steering system for leaks.
• Check overall thickness of front and rear disc brake pads. Examine brake disc surfaces.
• Clean brake pad contact points in calipers.
• Grease wheel center hubs.
• Check steering for absence of play, condition of suspension track rods, front axle joints, steering linkage, and joint disc.
• Check front control arm bushing for wear.
• Check brake and clutch system connectors and lines for leaks, damage, and incorrect positioning.
• Check for free movement of the parking brake cables.
• Adjust parking brake if necessary.
• Check all tire pressures (including spare). Correct if necessary.
• Check condition of tires (outer surfaces), tread wear and pattern; In case of uneven tread wear readjust wheel alignment if required.

Engine

• Read out diagnostic system with BMW scanners.
• Check engine cooling system/heater hose connections for leaks.
• Check coolant level and antifreeze protection level; add coolant if necessary.
• Check level of brake and clutch fluid in reservoir; add fluid if required.
• Check windshield washer fluid level and antifreeze protection. Fill up and/or correct if necessary.
• Check air conditioner for operation.
• Reset Service Indicator.

Body and Electrical

• Check battery electrolyte level and add distilled water if required.
• Perform battery load test.
• Check lighting system, i.e. headlights, foglights, parking, backup, license plate, interior (including map reading lights), glove box, flashlight, illuminated makeup mirrors, luggage compartment lights.
• Check instrument panel and dashboard illumination.
• Check all warning/indicator lights, check control.
• Check turn signals, hazard warning flashers, brake lights, horns, headlight dimmer/flasher switch.
• Check wiper and washer system(s); wiper blades, washer jet positions.
• Check condition and function of safety belts.
• Oil hood, trunk/tailgate, and door hinges.
• Grease hood, trunk/tailgate and door latches. Check operation of all latches.
• Check central locking/double lock.
• Check heater/air conditioner blower, rear window defogger.
• Check rear view mirrors.
• Visually examine the SRS airbag units for torn cover, obvious damage or attachment of decals, decorations, or accessories.

Inspection II

The BMW Inspection II Service is the bigger of the two inspection services recommended by BMW and it includes replacing spark plugs, bushings, flushing coolant, etc.

Visual Inspections

Undercarriage

• Check transmission and differential for leaks.
• Check rear axle for leaks. Visually check fuel tank, lines, and connections for leaks.
• Check condition, position, and mounting of exhaust system. Examine for leaks.
• Check power steering system for leaks.
• Check overall thickness of front and rear disc brake pads. Examine brake disc surfaces.
• Clean brake pad contact points in calipers.
• Grease wheel center hubs.
• Check steering for absence of play, condition of suspension track rods, front axle joints, steering linkage, and joint disc.
• Check front control arm bushing for wear.
• Check brake and clutch system connectors and lines for leaks, damage, and incorrect positioning.
• Check all tire pressures (including spare). Correct if necessary.
• Check for free movement of the parking brake cables. Adjust parking brake if necessary.
• Check condition of tires (outer surfaces), tread wear and pattern; In case of uneven tread wear readjust wheel alignment if required.
• Check thickness of parking brake linings.
• Half-shafts; check for leaks at flexible boots.
• Inspect entire body according to terms of rust prevention limited warranty.

Engine

• Read out diagnostic system with BMW scanners.
• Check engine cooling system/heater hose connections for leaks.
• Check level of brake and clutch fluid in reservoir; add fluid if required.
• Check windshield washer fluid level and antifreeze protection. Fill up and/or correct if necessary.
• Check air conditioner for operation.
• Reset Service Indicator.

Body and Electrical

• Check battery electrolyte level and add distilled water if required.
• Perform batter load test.
• Check lighting system, i.e. headlights, foglights, parking, backup, license plate, interior (including map reading lights), glove box, flashlight, illuminated makeup mirrors, luggage compartment lights.
• Check instrument panel and dashboard illumination.
• Check all warning/indicator lights, check control.
• Check turn signals, hazard warning flashers, brake lights, horns, headlight dimmer/flasher switch.
• Check wiper and washer system(s); wiper blades, washer jet positions.
• Check condition and function of safety belts.
• Oil hood, trunk/tailgate, and door hinges.
• Grease hood, trunk/tailgate and door latches. Check operation of all latches.
• Check central locking/double lock.
• Replace microfilter or Cabin Filter.
• Check heater/air conditioner blower, rear window defogger.
• Check rear view mirrors .
• Visually examine the SRS airbag units for torn cover, obvious damage or attachment of decals, decorations, or accessories.

Refresh: E46 M3 Maintenance

Once you start reaching the 100,000 mile mark, you might want look into changing or replacing all your suspension bushings and take care of your engine cooling system. See below for the list of E46 M3 maintenance items that will refresh your car and keep it feel like new.

Mandatory: E46 M3 Maintenance

Like all sports cars, the E46 M3 comes with a few problem areas. Some are minor and some are very serious like VANOS failures and subframe splits. If you’re considering to buy an E46 M3 or currently an owner, these are all the items you should know about and expect to take care if you have not already. Check out this section to take care of all E46 M3 maintenance that is mandatory. All suggested parts listed here are recommendations and you will need to research if you’re trying to diagnose your issue.

Rod Bearings

Problem: Excess heat and friction will cause your S54 rod bearings to wear overtime and at about 100k miles you should really look into replacing your rod bearings. There are some additives you can add to limit the wear, but it’s only short term. We did a full write up on treating your engine with Liqui Moly MoS2 with oil sample tests in case you’re curious. In the long run, you want to replace. BMW did create a service action recall to fix this premature issue, but still only short term.

Solution: Replace OEM rod bearings with WPC treated rod bearings.

Parts: ECS WPC Treated Genuine BMW Rod Bearings – Full Set – $495.95

VANOS Rebuild

Problem: There are multiple issues associated with the S54 VANOS unit. VANOS solenoid solder connection disconnects, cam bolts become lose and snap inside the engine, worn down oil pump disc, VANOS hub tabs break and gets tossed into the engine, VANOS piston seal o-ring deteriorates, and chain guide wears down. If you’re having timing issues or hear abnormal ticking coming from the solenoid, you definitely want to consider doing a VANOS overhaul. Some get lucky, but when the metal hub tab breaks off it’ll most likely go into your engine causing major damage.

Solution: Do a Beisan Systems VANOS overhaul. Please make sure to do some research on what parts you need for the S54 overhaul.

Parts: Beisan Systems S54 Solutions

VANOS High Pressure Oil Line

Problem: The S54 VANOS oil line creates up to 1,200 psi in the feed line and the neck area closest to the banjo bolt on the solenoid tends to crack or burst. The VANOS high pressure oil is used to maintain responsive and accurate camshaft adjustments. Failure in this line can do serious damage to your engine.

Solution: Replace OEM line with new updated BMW high pressure oil line or aftermarket high pressure oil line.

Parts: ECS S54 Exact-Fit Stainless Steel Vanos Line – $68.95

Subframe/Chassis Reinforcement Kit

Problem: The rear mounting points for the subframe can rip out in the sheet metal caused by excessive torsion load from the differential to the chassis. We’ve literally seen a chassis split in half!

Solution: The better of the two solution is to weld metal plates on the problem areas with kits provided by Turner, Bimmerworld, Redish Motorsport, VAC, HPF, and Achilles to name a few. The other solution was an epoxy method serviced by BMW as a recall, however welding is a more “permanent” fix although it is not 100% guaranteed.

Parts: Turner Motorsport Rear Subframe/Chassis Reinforcement Kit– $129.95

Constant Pressure Valve (CPV)

Problem: The CPV has an o-ring that tends to flatten and harden over time because of excessive heat which causes a leak in the line. The valve is located behind the exhaust manifolds which makes it a must-replace job if you’re taking out the headers for whatever reason.

Solution: High temperature o-ring. Replacement of the valve takes about 1.5 hours or about 5 minutes when the headers are off.

Part: ECS Heavy duty Constant Pressure Valve O-Ring– $5.95

Radiator

Problem: The OEM radiator has plastic end tanks which are prone to crack caused by high-low temperatures. Coolant temperatures can reach up to 207 degrees under normal operating conditions and quite possibly higher during track days. Plastic expands in heat and contracts in cooler conditions so it’s just a matter of time until your OEM end tanks leak!

Solution: Replace with an all aluminum radiator.

Parts: CSF High Performance Radiator, Turner/Fluidyne Radiator Upgrade.

Radiator Hose

Problem: The OEM coolant/radiator hose gets brittle and cracks overtime leading to leaks. Just like the radiator issue above, hot-cold temperatures will prematurely wear out the OEM material. If you’re upgrading your radiator to all aluminum, you might as well spend the extra $80 to upgrade your hose kit.

Solution: Replace upper and lower OEM radiator hose with a silicone radiator hose kit.

Parts: ECS Silicone Hose Kit – $123.95

Differential Bolts

Problem: Excessive torsion load may cause stock differential bolts to snap. Even when you accelerate and decelerate, the drivetrain load causes force and adds stress on the differential bolts. Now, go out to the track where you put the car in a more severe environment, you might want to really consider replacing bolts. $12 for a pair is worth it.

Solution: Replace with updated BMW-part-number differential bolts.

Part: Transmission Mounting Bolt M12x50 – $5.09

Rear Shock Mounts

Problem: There have been many reports on M3Forum on the rear shock mounts blowing out of the washer and causing a bit of damage to the shocks. If you hear squeaking, rattling, or clunking it may be a sign that the RSM is going bad. Monitor around 60,000 miles.

Solution: Replace OEM rear shock mounts with aftermarket reinforced and redesigned  mounts.

Parts: E46 M3 Rear Shock Mounts

Rear Trail Arm Bushings (RTAB)

Problem: Premature wear of OEM bushing can result in poor handling, excessive tire wear, and alignment issues. In some cases, members on M3Forum have reported premature bushing wear at ~40,000 miles of daily driving.

Solution: Replace with OEM + RTAB Limiter Kit, Delrin, Monoball or polyurethane bushings. Delrin or polyurethane can cause bind on your multi-lateral suspension causing more damage to your parts. A lot of people recommend using rubber RTAB with a Limiter Kit or monoball.

Part: E46 M3 Rear Trail Arm Bushing

Front Shock Tower Reinforcement Plate

Problem: When using aftermarket camber plates, the front strut tower may began to deform or crack when driving in “poor road conditions” due to uneven distribution of pressure.

Solution: Install BMW Upper Strut Mount Reinforcement Plates on each tower.

Parts: Front Upper Strut Mount Reinforcement Plate – $11.28

Rear Spring Perch Reinforcement Plate

Problem: The aluminum cast construction of the lower arm, only on the E46,  may cause the spring perch to deform or crack. Similar to the strut tower reinforcement, the uneven load from an aftermarket spring perch may cause improper seating thus damaging the suspension. This applies if you have after market height adjusters.

Solution: Install Rear Spring Perch Reinforcement plates.

Parts: Rogue Engineering Rear Spring Perch Reinforcement Plates.

Shoutout to Obioban for the tremendous E46 M3 maintenance guidance and help from the M3Forum community and Bimmerzone for the maintenance I and II information.