E46 Valve Cover Gasket —
Stop the oil leak for good

Twist the three locking tabs counter-clockwise and pull off the cabin filter cover. Remove the filter. Then remove the four T30 Torx screws holding the filter housing to the firewall. Remove the housing — this gives you critical access to the back row of valve cover bolts.

Remove both engine covers — four plastic clips each plus 10mm bolts underneath. Unscrew the oil filler cap. Disconnect the ignition coil electrical connectors by lifting the locking tab and pulling the connector off. Label each coil 1–6 front to back if you want to reinstall them in the same position.

Each coil is held by one 10mm bolt. Remove the bolt and pull the coil straight up out of the spark plug tube. Some will be stuck — use a flat head screwdriver through the clip opening and lever gently to pop them loose. Do not use needle nose pliers on the coil body.

The valve cover has 15 bolts in a specific pattern including around the coil tubes. Remove them all with a 10mm socket. Work in a star pattern from the outside in. The bolts have rubber grommet seals — set them aside. Inspect each grommet for cracking or hardening and replace any that are damaged.

With all bolts out, lift the valve cover straight up. It may be stuck to the old gasket — tap gently with a rubber mallet if needed. Do not pry between the cover and head with a screwdriver — you'll damage the sealing surface. Once off, clean the mating surface on the head and the cover with brake cleaner and a clean rag.

Press the new main gasket into the groove in the valve cover — it should seat firmly all the way around. Press the new spark plug tube seals into position in the cover. No sealant is needed or recommended with a quality gasket set. Drop the cover carefully straight down onto the head.

Install new rubber grommets on each bolt. Thread all bolts in by hand first, then torque to 10 Nm in a star pattern starting from the center working out. Do not overtorque — the valve cover is aluminum and 10 Nm is the absolute maximum. Reinstall coils, reconnect connectors, reinstall engine covers and cabin filter housing.

Same as the valve cover guide — remove the cabin filter housing (three tabs and four T30 screws) and both engine covers (clips and 10mm bolts). This gives full access to all six coils in a single row across the top of the engine.

Unplug each coil connector by lifting the locking tab. Remove the single 10mm bolt per coil. Pull each coil straight up — they can be stuck. Label them 1 through 6 front to back as you remove them so you can reinstall in the same positions. Inspect the boot on the bottom of each coil for cracks or oil contamination.

With a 5/8" spark plug socket and a long extension, reach down into each plug tube. The plugs are deep — you need at least 6 inches of extension. Break each loose slowly. If you feel significant resistance stop and apply penetrating oil — forcing a seized plug can strip the threads in the aluminum head.

NGK BKR6EQUP plugs come pre-gapped at 0.7mm from the factory — do not adjust the gap. Thread each plug in by hand several turns before using the ratchet. Torque to 25 Nm. Do not use anti-seize on NGK plugs — they have an anti-seize coating built in and adding more throws off the torque reading.

Apply a thin coat of dielectric grease to the inside of each coil boot — this prevents voltage leaks and makes future removal easier. Push each coil straight down firmly until it seats on the plug. Reinstall the 10mm bolt and torque to 8 Nm. Reconnect each electrical connector until it clicks.

Clear any stored misfire codes with your scanner. Start the engine and listen for smooth idle. Take a progressive test drive — the engine should pull cleanly through the entire RPM range. If a misfire code returns on a specific cylinder and you replaced both the plug and coil, move on to checking compression on that cylinder.

Drive the car for 10–15 minutes before the fluid change. Warm gear oil flows out completely — cold thick oil leaves old contaminated fluid behind. After driving, jack the car level. The diff must be level when you fill it or you'll overfill or underfill.

The rear differential has two plugs, both 14mm hex. The fill plug is on the side of the diff housing — it faces slightly downward at an angle. The drain plug is at the very bottom. Both look identical from underneath. Use a strong flashlight to find them before you start.

Insert the 14mm hex socket into the fill plug and break it loose. These are often very tight on an unmaintained car — use a breaker bar with a long handle for leverage. Once loose, thread it out by hand and set aside. Confirm you can get it out before proceeding to the drain plug.

Position your drain pan under the diff. Remove the drain plug and let the old fluid drain completely — give it at least 10 minutes for a warm drain, longer if cold. The color and smell of the old fluid tells you a lot: black and burnt means severely overdue, dark brown is typical for a neglected service.

Thread in the new drain plug with its built-in O-ring and torque to 60 Nm. Using the fluid transfer pump, pump Redline 75W-90 through the fill hole. Fill slowly and keep pumping until fluid weeps out of the fill hole. That's full. The rear diff takes approximately 0.85–1.0 liters depending on model year.

Lower the car and take it for a 10–15 minute drive. Come back and check both plugs for any seepage. The new O-ring plugs should be completely dry. Check again after the first 100 miles.

Lay rags over both front fenders and around the brake reservoir. Use a turkey baster or syringe to remove as much old fluid from the reservoir as possible. Refill with fresh ATE Typ 200 to the MAX line. Keep a bottle of fresh fluid nearby — never let the reservoir run empty or you'll introduce air into the system.

Jack the car and remove all four wheels for the best access. Each caliper has a bleeder screw — a small nipple with a rubber dust cap. Remove the dust caps and confirm each bleeder screw will turn before proceeding. Seized bleeder screws are common on older cars — apply penetrating oil and let it soak if any are stuck.

Attach the clear tubing to the bleeder screw and put the other end in a jar of waste fluid. Have your helper pump the brake pedal 3–4 times and hold it down. Open the bleeder screw 1/4 turn — old fluid flows into the tube. Close the screw before your helper releases the pedal. Repeat until the fluid coming out is clear with no bubbles. Check reservoir level frequently.

Rear passenger → rear driver → front passenger → front driver. Keep topping off the reservoir between corners. Never let it drop below the MIN line. A typical full flush uses 500–750ml of fluid for all four corners. One liter of ATE Typ 200 is the right amount to buy.

Fill the reservoir to the MAX line with fresh fluid. Replace the cap. Pump the brake pedal firmly several times to restore pedal feel — it should be firm with no spongy feeling. Before driving on public roads, do a low-speed brake test in a safe area. Pedal should be firm and stopping power should be immediate.

Jack the car and support on stands. The transmission mount is located at the rear of the transmission, bolted to a crossmember that runs across the tunnel. From underneath you'll see a rubber-isolated bracket holding the rear of the trans. Spray all the bolts with penetrating oil and let them soak before attempting removal.

Place a floor jack under the transmission pan with a piece of wood to protect it. Raise just enough to take the load off the mount — not enough to lift the car. The transmission needs to be supported throughout this job so it doesn't drop and strain the driveshaft or wiring harnesses.

The crossmember is held to the body by four 16mm bolts — two per side. These are often seized on older cars. Apply significant force with a breaker bar and long handle. If they won't budge, apply more penetrating oil and let it soak overnight before trying again. Do not use an impact gun — these bolts need to be torqued accurately on reinstall.

With the crossmember loose, remove the 13mm nuts holding the transmission mount to the transmission bracket. The old mount will drop down — compare it to the new unit. A failed rubber mount will show obvious collapse, cracking, or complete separation of the rubber from the metal.

Position the new mount and thread the 13mm nuts by hand. Reposition the crossmember and thread the 16mm bolts in by hand. Torque the mount nuts to 20 Nm first, then torque the crossmember bolts to 64 Nm. Lower the floor jack from the transmission slowly once everything is torqued.

Lower the car and take it for a test drive. Accelerate firmly from a stop — the clunking should be completely gone. The shifter should feel more precise. If you still feel movement, check that all bolts were properly torqued and that the driveshaft guibo and carrier bearing are also in good condition.