N52 Engine Swap: Step by Step

Out

1. Hood up, negative battery cable off (BMW).
2. Underbody panels off: screws out, slide each panel out (BMW).

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3. Drain the oil and coolant. Expansion tank cap open, then the radiator drain plug and the hose at the thermostat (BMW). Old coolant never goes back in (BMW).
4. Exhaust out in one piece (BMW): jack under it, flange nuts off (BMW), then the clamp between the pipes (shop way). It weighs about 50 kg: two people (BMW).

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5. Bumper and front end off for crane room (shop way).
6. Air box, fan cowl and radiator out. Automatic: unhook the gearbox oil cooler from the cowl and leave it on its lines (BMW). Open a gearbox line and fluid comes out: catch it (BMW).

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7. Coolant hoses off the thermostat and the electric water pump. Moving the pump over? Don't drop or force it: a hard knock means a new pump (BMW). Leave the coolant pipe on the engine block (BMW).

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8. Intake manifold off: lift it 5 to 10 cm, turn the front 45°, unclip the tank vent, lift it out. Cover every open port so nothing drops in (BMW).
9. Fuel rail off. Goggles and gloves: the line is under pressure (BMW). Blow the fuel back to the tank, 3 bar max, clamp the hose, then the rail comes off (BMW). Fuel runs out when the line comes off: catch it (BMW).

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10. Electronics box open, DME plugs off, then the ignition and engine harness off to one side (BMW). Unplug the gearbox plug too (turn to unlock) and cap its sleeve (BMW). Static damages the control unit: follow BMW's static protection (BMW).

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11. Vacuum line out: open the quick release, pull the line free (BMW).
12. A/C compressor and steering pump down on the front subframe, lines still on (BMW). The A/C lines are under pressure: never open them (BMW).

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13. Gearbox off the engine. Jack and strap under the gearbox first (shop way). Check the gearbox bolt threads for rust: clean them before they come out (BMW). Turn the engine by the crank pulley until a converter bolt shows in the opening, undo it, repeat for all six (BMW). Then the engine-to-gearbox bolts (Figure 1). Keep the converter on the gearbox (shop way): BMW warns a loose converter can damage the impeller driver.

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14. Crane on first. Towing hook in, lifter on the mounting eyes only (BMW). Take the weight, then the engine mount nuts come off (shop way).

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15. Out. BMW raises the engine about 10 cm to take the heat exchanger pipes off with the exchanger (automatic). With the gearbox left in, slide the engine forward off the dowels and the converter before it goes up (shop way: check this order on the car).

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In

1. Move parts to the new engine. Drive plate on new bolts, 30 Nm then 125 Nm (BMW). Manifolds on new nuts, 20 Nm (BMW), and new gaskets (shop way). Mind the oxygen sensors: they get damaged easily when the manifolds move (BMW). Water pump on new aluminium bolts, 10 Nm then 90°, and turn a reused pump one full turn by hand (BMW).

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2. Line it up before it goes on. The drive plate hole shows in the oil pan opening, converter holes line up with the drive plate, dowel sleeves in place, damaged ones replaced (BMW). A converter that isn't seated can damage the pump impeller driver as the engine bolts up (BMW).
3. 6HP: gearbox bolts 1 to 11 in order (Figure 1). BMW: observe the fastening order without fail. GA6L45R: its order isn't on this page, send us your VIN. Aluminium bolts new, torque then angle; steel Torx bolts to their own torque (BMW). Converter bolts 56 Nm (BMW).
4. Everything else back in reverse, torques from the everything you need page. New: exhaust nuts and gasket, intake manifold gaskets, injector seals if you pulled them (BMW). Oil drain plug on a new sealing ring, 25 Nm. Fuel rail bolts 9 Nm. Heat exchanger to the front axle carrier 8 Nm (BMW's N52 table).
5. Fill: 6.5 L oil with the filter. Overfilling damages the engine (BMW). 8.4 L of new coolant (BMW's parts catalog).
6. Check: gearbox fluid level with BMW's approved fluid (BMW). Then BMW's last step: check the engine computer for faults (shop way: a BMW scan tool reads it).

Replacing the gearbox mount too?

Support the gearbox first. Mount to gearbox and cross member: 19 Nm (BMW).

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Steps come from BMW's repair instructions for the N52 and the automatic gearbox; the shop way is labeled. Check yours by VIN.