Engine - Repair (6-cyl) BMW Z3 E36

ENGINE IDENTIFICATION

Note. For repair procedures not covered in this article, see ENGINE OVERHAUL PROCEDURES article in GENERAL INFORMATION.

ENGINE IDENTIFICATION CODES

FUEL PRESSURE RELEASE

Fuel system pressure release procedure is not available from manufacturer. Disconnect negative terminal of fuel pump connector, under left rear side of vehicle. It may also be possible to remove fuel pump relay, start engine and run engine until fuel pressure drops (engine stalls).

On 3-series, fuel pump relay is located in fuse/relay block in left rear corner of engine compartment. On 5-series, fuel pump relay is located in right rear corner of engine compartment, next to DME control unit and DME master relay.

Note. For reassembly reference, label all electrical connectors, vacuum hoses and fuel lines before removal. Also place mating marks on engine hood and other major assemblies before removal.

Note. Remove transmission before removing engine. For vehicles with automatic transmissions, see TRANSMISSION REMOVAL & INSTALLATION article in TRANSMISSION SERVICING. For vehicles with manual transmissions, see RWD article in CLUTCHES.

Scheme 1

1. Remove engine splash guard. Release hinge at hood, and prop hood open past center position. Disconnect negative battery cable. Battery is located in trunk.
2. Remove air cleaner/air mass sensor assembly. Pull off hoses for idle speed control valve and crankcase breather. Remove transmission.
3. Remove generator air intake duct. Remove side rivets, and pull out radiator cooling fan cowl. Using Pulley Holder (11-5-030) and 32-mm Wrench (11-5-040), turn cooling fan nut clockwise to remove cooling fan.
4. Drain engine coolant. Disconnect radiator hoses, coolant level switch and transmission oil cooler lines from radiator (if equipped). Disconnect A/C temperature switch from side of radiator. Remove clips and radiator.
5. Disconnect coolant hoses from heater control valve and heater at engine compartment firewall. Remove electrical lead along fresh air intake duct. Remove fresh air intake duct. Disconnect throttle cable, and pull out cable together with rubber retainer.
6. Disconnect vacuum hose from power brake booster. Remove oil filler cap and engine covers. (Scheme 1)
7. Remove ground strap from timing case cover. Remove ignition coil cover plate. Disconnect wiring from ignition coils, and remove plate together with wiring.
8. Detach hose at cylinder head breather vent. Disconnect wiring at air temperature sensor. Disconnect wiring, vacuum hoses and fuel lines at throttle body. Disconnect vacuum hose from idle speed control valve (on manifold).
9. Disconnect hoses from fuel lines at engine carrier. Remove support brackets for intake manifold. Remove intake manifold from cylinder head. Disconnect wiring from temperature gauge, temperature sensor, oil pressure switch and idle speed control valve.
10. Disconnect wiring from cylinder identifying sensor and DME pulse sensor. Disconnect wiring from starter and generator. Remove screws and wiring harness duct. Set wiring harness aside.
11. Note serpentine belt routing. Insert socket into drive belt tensioner bolt. Compress tensioner by slowly rotating socket clockwise, and remove drive belt.
12. Remove bolts and power steering pump from engine. DO NOT disconnect power steering lines. Remove bolts and power steering pump oil supply tank. Hang power steering pump and oil tank aside.
13. Insert socket into A/C compressor drive belt tensioner. Compress tensioner by slowly rotating socket clockwise, and remove A/C compressor drive belt. Remove 4 bolts and A/C compressor. DO NOT disconnect refrigerant lines.
14. Attach Engine Lifting Device (11-0-020) to engine lift points. Remove ground strap and right engine mount. Remove left engine mount nut. Remove engine from vehicle.

Installation

1. To install, reverse removal procedure. Ensure serpentine belt is correctly routed and properly seated in grooves. Turn 32-mm Wrench (11-5-040) counterclockwise, and tighten cooling fan nut. See TORQUE SPECIFICATIONS.
2. Fill and bleed cooling system. To do so, turn ignition on. Place A/C-heater controls on HEAT position to ensure heater valve is open. Add coolant to expansion tank. Run engine at 2500 RPM and add coolant to expansion tank as level drops.

Removal (5-Series)

1. Remove transmission. Remove engine splash guard. Disconnect battery cables, and remove battery. Remove battery tray.
2. Remove generator air intake duct. Disconnect wiring at air mass sensor. Remove air cleaner/airflow sensor assembly. Remove side rivets, and pull out radiator cooling fan cowl.
3. Using Pulley Holder (11-5-030) and 32-mm Wrench (11-5-040), turn cooling fan nut clockwise to remove cooling fan. Drain engine coolant. Plug is located on exhaust manifold side of engine block.
4. Disconnect radiator hoses, coolant level switch and transmission oil cooler lines (if equipped) from radiator. Remove trim next to radiator. Disconnect A/C temperature switch from side of radiator. Remove clips and radiator.
5. Disconnect coolant hoses from heater control valve and heater at engine compartment firewall. Remove nut, spacer and throttle cable cover. Disconnect throttle cable, and pull out cable together with rubber retainer.
6. Disconnect vacuum hose from power brake booster. Remove oil filler cap and engine covers. Remove ignition coil ground strap from timing case cover. Remove ignition coil cover plate. Disconnect wiring from ignition coils, and remove plate together with wiring.
7. Detach hose at cylinder head breather vent. Disconnect wiring at air temperature sensor. Disconnect wiring, vacuum hoses and fuel lines at throttle body. Disconnect throttle valve switch. Disconnect vacuum hose from idle speed control valve (on manifold).
8. Disconnect hoses from fuel lines at engine carrier. Remove intake manifold from cylinder head. Disconnect wiring from temperature gauge, temperature sensor, oil pressure switch and idle speed control valve.
9. Disconnect wiring from cylinder identifying sensor and DME pulse sensor. Detach connector, for oxygen sensor, from holder. Disconnect wiring from starter and generator. Remove bolts and wiring harness duct. Set wiring harness aside.
10. Note serpentine belt routing. Insert socket into drive belt tensioner bolt. Compress tensioner by slowly rotating socket clockwise, and remove drive belt.
11. Remove bolts and power steering pump from engine. DO NOT disconnect power steering lines. Remove bolts and power steering pump oil supply tank. Hang power steering pump and oil tank aside.
12. Insert socket into A/C compressor drive belt tensioner. Compress tensioner by slowly rotating socket clockwise, and remove A/C compressor drive belt. Remove A/C compressor. DO NOT disconnect refrigerant lines.
13. Attach Engine Lifting Device (11-0-020) to engine lift points. Remove ground strap and right engine mount. Remove left engine mount nut. Remove engine from vehicle.

1. To install, reverse removal procedure. Ensure serpentine belt is correctly routed and properly seated in grooves. Tighten cooling fan nut. See «TORQUE SPECIFICATIONS»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl__torque-specifications) .
2. Fill and bleed cooling system. To do so, add coolant to expansion tank and fill to level mark. Place A/C-heater control on WARM setting to ensure heater valve is open. Start and run engine at fast idle speed. Open bleed screw on expansion tank and continue to add coolant to expansion tank as coolant level drops. Tighten bleed screw as soon as coolant is free of air bubbles.

Removal

1. Remove engine splash guard. On 3-series, release hinge at hood, and prop hood open past center position. On all models, disconnect negative battery cable. Battery is located in trunk of 3-series.
2. Remove air cleaner/air mass sensor assembly. Drain engine coolant. Disconnect coolant hoses from heater control valve and heater at engine compartment firewall.
3. On 3-series, remove generator air intake duct. Remove grille from fresh air intake duct, below wiper arms. Remove screws and electrical lead along fresh air intake duct. Remove right holder, left screw and fresh air intake duct.
4. On 5-series, remove nut, spacer and throttle cable cover. On all models, disconnect throttle cable, and pull out cable together with rubber retainer. Disconnect vacuum hose from power brake booster.
5. Remove oil filler cap, screw caps, screws and engine covers. (Scheme 1) If necessary, pull forward on cover and swing it out over oil filler neck. Remove ignition coil ground strap from timing case cover. Remove ignition coil cover plate. Disconnect wiring from ignition coils, and remove plate together with wiring.
6. Detach hose at cylinder head breather vent. Disconnect wiring at air temperature sensor. Disconnect wiring, vacuum hoses and fuel lines at throttle body.
7. Disconnect vacuum hose from idle speed control valve (on manifold). Disconnect hoses from fuel lines at engine carrier. On 3-series, remove support brackets for intake manifold. On all models, remove intake manifold from cylinder head. (Scheme 2)

To install, reverse removal procedure. Ensure no parts fall into intake ports. Replace oval intake manifold gasket. Fill and bleed cooling system.

Scheme 2

Removal & Installation

Remove exhaust manifold flange bolts. Remove exhaust manifold. To install, reverse removal procedure. Tighten nuts to specification. See TORQUE SPECIFICATIONS .

1. Remove intake manifold. See «INTAKE MANIFOLD»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl). Remove thermostat housing. Disconnect wiring from ignition coils, and remove coils.
2. Remove cylinder head cover. Remove pulse sensor from side of cylinder head. Detach wiring harness duct above thermostat housing opening. Remove upper timing case cover and front engine lifting eye.
3. Pull off camshaft cover. With cylinder No. 1 coming up on TDC, turn crankshaft in normal direction of rotation until cylinder No. 1 intake and exhaust cam lobes face each other. Arrows on sprockets face up. Use TDC Aligning Plug (11-2-300) to hold crankshaft in TDC position.
4. Install Camshaft Locating Fixture (11-3-240) to cylinder head. (Scheme 32)or (Scheme 3). Press down on upper chain tensioner and hold in place using Holding Spring (11-3-290). (Scheme 4)
5. Remove oil line connector and electrical connector from Variable Camshaft Control (VANOS). (Scheme 17) Remove upper timing chain cover with VANOS assembly. (Scheme 5)
6. Remove camshaft sprocket nuts (intake) and bolts (exhaust). Remove intake sprocket thrust washer. Remove upper camshaft sprockets and upper timing chain.
7. Remove upper chain tensioner. Remove chain guide directly below front end of camshaft. Remove lower timing chain tensioner plug, spring and piston. Remove lower chain sprocket from exhaust camshaft and tie up lower timing chain.
8. Remove 2 bolts directly below front end of camshaft. Use E12 Torx Bit (11-2-250) to loosen cylinder head bolts in several steps, starting from outside bolts and working toward inside (center) bolts. Remove cylinder head.

Note. Some cylinder head washers are staked into position.

Scheme 3

Scheme 4

Scheme 5

Scheme 6

Scheme 7

Scheme 8

Scheme 9

Scheme 10

Scheme 11

Scheme 12

Scheme 13

Scheme 14

Scheme 15

Scheme 16

1. Ensure cylinder head dowels are installed and not damaged. Remove oil from head bolt threaded holes in cylinder block. Lubricate threads of NEW head bolts. NOTE: A.012" (0.3 mm) thicker cylinder head gasket is available for machined cylinder heads.
2. Install cylinder head gasket. Wait for hydraulic cam followers to compress. See «VALVE TRAIN SERVICING PRECAUTIONS»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl__valve-train-servicing-precautions). Install cylinder head. Tighten NEW, lightly oiled cylinder head bolts. (Scheme 6) See «TORQUE SPECIFICATIONS»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl__torque-specifications). NOTE: When installing a new cylinder head, also use NEW washers, but DO NOT stake them into place.
3. Ensure camshafts are aligned with Camshaft Locating Fixture (11-3-240). (Scheme 32)or (Scheme 3). Install lower timing chain on sprocket and install on exhaust camshaft.
4. Ensure arrow on exhaust camshaft sprocket is up and tapped holes are at left side of slots in sprocket. Finger tighten bolts.
5. Install Chain Adjusting Screw (11-3-390) to side of cylinder head. (Scheme 7) Tighten screw finger tight. Tapped holes in camshaft should now be centered in sprocket slots.
6. Install chain guide and upper chain tensioner. Install intake pulse sensing wheel (if removed). Install thrust washer bolts to intake camshaft. DO NOT mix bolts for cylinder head cover and sprockets. (Scheme 8)and (Scheme 9).
7. Install upper timing chain and sprockets to camshafts. Ensure tapped camshaft holes are centered in sprocket slots. (Scheme 10) Install intake camshaft thrust washer and tighten nuts to specification. See «TORQUE SPECIFICATIONS»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl__torque-specifications).
8. Install thrust washer on exhaust camshaft and tighten bolts finger tight. Turn both sprockets clockwise as far as possible. (Scheme 11) Push splined gear of VANOS housing as far as stop. (Scheme 12)
9. Apply Sealant (3-Bond 1209) to top corners of cylinder head. Install, but do not tighten, upper timing chain cover and VANOS assembly. (Scheme 13)
10. Turn VANOS splined shaft to engage splines on camshaft. Turn upper timing chain/sprockets counterclockwise until camshaft sprocket meshes with VANOS splined shaft. Push VANOS splined shaft into camshaft sprocket splines. (Scheme 14), (Scheme 15) and (Scheme 16).
11. Tighten upper timing chain cover and VANOS assembly nuts. Remove Holding Spring (11-3-290) from upper chain tensioner. (Scheme 4) Tighten Chain Adjusting Screw (11-3-390) and camshaft sprocket bolts to specification. See «TORQUE SPECIFICATIONS»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl__torque-specifications).
12. Remove Chain Adjusting Screw (11-3-390). (Scheme 7) Install timing chain tensioner with groove in piston perpendicular to tensioner rail. Remove TDC Aligning Plug (11-2-300) and Camshaft LocatingFixture (11-3-240) from engine.
13. Install VANOS Air Hose Adapter (11-3-450) to oil fitting and Jumper Harness (12-6-410) to VANOS solenoid connector. (Scheme 17) Apply 28-110 psi (2.0-8.0 kg/cm 2 ) of air pressure to hose adapter.
14. Connect positive lead of jumper harness to positive terminal of battery and ground lead to negative terminal of battery. Using a vernier caliper, measure distance camshaft moves. (Scheme 18)
15. Camshaft sprocket should move.33-.49" (8.5-12.5 mm). If not, check VANOS assembly. Remove VANOS testing tools. Connect VANOS oil fitting and electrical connector. Ensure cylinder head cover gasket is correctly seated at rear of cylinder head. To complete installation, reverse removal procedure.

Scheme 17

Scheme 18

1. Install Flywheel Holder (11-2-170) to hold flywheel in place. If necessary, remove 6 bolts and vibration damper. Remove bolt, washer and vibration damper hub.
2. Remove crankshaft front seal. (Scheme 19) To install, reverse removal procedure. Use Seal Installer (11-3-280), hub bolt and washer to press in new seal.

Scheme 19

1. Remove timing chain and sprockets from cylinder head. See CYLINDER HEAD. Remove lower timing case cover. (Scheme 19) Fold down tensioner rail, and lift out timing chain.
2. Remove retainers and timing chain guide. Remove chain tensioner for oil pump timing chain. To install, reverse removal procedure.

CAMSHAFT

Note. Intake or exhaust camshaft may be replaced with engine installed in vehicle.

Scheme 20

Scheme 21

1. On 3-series, release hinge at hood, and prop hood open past center position. On all models, remove side rivets, and pull out radiator cooling fan cowl. Using 32-mm Wrench (11-5-040) and Pulley Holder (11-5-030), turn cooling fan nut clockwise to remove cooling fan.
2. On 3-series, remove grille from fresh air intake duct, below wiper arms. Remove screws and electrical lead along fresh air intake duct. Remove right holder and fresh air intake duct.
3. On all models, remove oil filler cap, screw caps, screws and engine covers. Remove ignition coil ground strap from timing case cover. Remove ignition coil cover plate. Disconnect wiring from ignition coils, and remove plate together with wiring. Remove ignition coils.
4. Detach hose at cylinder head breather vent. Remove cylinder head cover. Remove pulse sensor from side of timing case cover. Remove wiring harness duct located directly above thermostat housing.
5. Remove engine lift bracket and upper timing case cover. Pull off camshaft cover. With cylinder No. 1 coming up on TDC, turn crankshaft in normal direction of rotation until cylinder No. 1 intake and exhaust cam lobes face each other. Arrows on sprockets should face up. NOTE: If camshaft position has to be turned so much that valves on 1st and 6th cylinders are moved, first turn crankshaft 30 degrees in normal direction of rotation past TDC. This will keep valves from contacting pistons. After aligning camshafts, turn crankshaft back to TDC position.
6. Remove valve cover mounting studs. Use Camshaft Locating Fixture (11-3-240) to align and hold camshafts. (Scheme 32)or (Scheme 3). Camshafts may be turned using a 27-mm open end wrench. Use TDC Aligning Plug (11-2-300) to hold crankshaft in TDC position.
7. Remove timing chain tensioner from side of timing case cover. Press down on upper chain tensioner and hold in place using Spring Holder (11-3-290). (Scheme 6) Remove timing chain sprockets and timing chain. (Scheme 20) See «CYLINDER HEAD»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl).
8. Prepare Camshaft Fixture (11-3-260) and Adapter (11-3-270). (Scheme 21) Remove spark plugs from cylinder head. Mount and bolt fixture in spark plug holes. Tighten fixture bolts. See «TORQUE SPECIFICATIONS»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl__torque-specifications). CAUTION: Camshaft may be damaged during removal/installation if fixture is not used. In addition, valves may be bent by contacting tops of pistons.
9. Load bearing caps by turning eccentric shaft on fixture. Remove bearing cap bolts. Slowly release load from bearing caps, and remove fixture. Lift out bearing caps and camshafts.
10. Hold hydraulic cam followers with an assistant or using Suction Cups (11-3-250). Lift out bearing plate complete with hydraulic cam followers. Inspect bearing surfaces of hydraulic cam followers for wear.

Note. On 3-series, camshafts, camshaft bearing caps and camshaft bearing plates (journals) are marked with "A" for exhaust and "E" for intake. On 5-series, camshafts, camshaft bearing caps and camshaft bearing plates (journals) are marked with AD for exhaust and ED for intake. Intake camshaft also has a notch cut into camshaft sprocket mounting flange.

1. Check centering sleeves on mounting bolts for bearing caps No. 2 and 7. Install camshaft so intake and exhaust valve camshaft lobes for cylinder No. 1 face each other. Install bearing plate complete with hydraulic cam followers. Install camshaft bearing caps.
2. Install fixture, and tighten fixture bolts to 17 ft. lbs. (23 N.m). Apply a load on bearing caps by turning eccentric shaft on fixture. Tighten bearing cap bolts to specification. See «TORQUE SPECIFICATIONS»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl__torque-specifications) . Slowly release load, and remove fixture. Wait for hydraulic cam followers to compress. See «VALVE TRAIN SERVICING PRECAUTIONS»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl__valve-train-servicing-precautions) .
3. Install exhaust camshaft timing chain sprocket with arrow pointing up and slots aligned with bolt holes at left. Ensure pulse sensor wheel is installed on intake camshaft.
4. Install camshaft sprockets and timing chain. See «CYLINDER HEAD»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl) . Install and adjust VANOS assembly. See «CYLINDER HEAD»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl) .
5. Install timing chain tensioner with groove in piston perpendicular to tensioner rail. Ensure cylinder head cover gasket is correctly seated at rear of cylinder head. To complete installation, reverse removalprocedure.

1. Remove transmission. See appropriate article in CLUTCHES (M/T), or REMOVAL & INSTALLATION article in TRANSMISSION SERVICING (M/T). Use Flywheel Holder (11-2-170) to hold flywheel in place. On manual transmission vehicles, remove 6 bolts and clutch pressure plate. On all vehicles, remove flywheel. Remove crankshaft rear cover and seal.
2. With crankshaft cover removed, use Seal Installer (11-1-260) to install crankshaft rear seal. Place Sleeve (11-2-213) over crankshaft. Lubricate crankshaft rear seal, and slide cover into place. To complete installation, reverse removal procedure.

Note. Using Crankshaft Ball Bearing Installer (11-2-030) and Drift (00-5-000), install transmission shaft pilot bearing in crankshaft (if necessary).

Hold water pump pulley on drive belt and remove bolts. Remove drive belt and pump pulley. Remove water pump bolts. Use two 6 mm metric bolts in water pump threaded holes to press water pump out. Lightly lubricate "O" ring, and install water pump. To complete installation, reverse removal procedure.

Remove fan coupling with fan wheel and fan cowl. Drain and dispose of coolant.

Installation

Replace seal.

Drain plug for coolant in engine block: M14 x 1.5 thread - Tightening torque: 18 Ft. Lbs. (25 N.m)

Bleed cooling system and checking for water leaks.

Scheme 22

Unfasten water hoses.

Scheme 23

Unscrew suspension eye.

Scheme 24

Remove cable channel.

Scheme 25

Unfasten thermostat housing.

Scheme 26

Installation

Keep sealing faces clean and free of oil.

Replace seal.

Scheme 27

Installation

Check installed direction.

Vent with arrow facing upwards

Replace seal.

Scheme 28

1. Drain engine oil. Disconnect wiring from oxygen sensor. Detach wiring from holder at transmission crossmember.
2. Remove bolts and exhaust pipes from exhaust manifold. On vehicles with automatic transmission, remove crossmember for center of gravity suspension.
3. Remove bolts, and detach exhaust pipe from transmission holder. Detach rubber rings from exhaust pipes. Remove rear bolts and lower exhaust assembly down.
4. On all models, release hinge at hood, and prop hood open past center position. Remove air cleaner/air mass sensor assembly.
5. Remove generator air intake duct. Remove rivets, and pull out radiator cooling fan cowl. Using Pulley Holder (11-5-030) and 32-mm Wrench (11-5-040), turn cooling fan nut clockwise to remove cooling fan. Remove clips at top of radiator.
6. On 3-series, remove grille from fresh air intake duct. Remove electrical lead along fresh air intake duct. Remove right holder and fresh air intake duct.
7. On all models, remove guide tube for engine oil dipstick. Note serpentine belt routing. Insert socket into drive belt tensioner bolt. Compress tensioner by slowly rotating socket clockwise, and remove drive belt.
8. Remove power steering pump bolts. Remove power steering pump. DO NOT disconnect power steering lines. Remove bolts and power steering pump oil supply tank. Hang power steering pump and oil tank aside.
9. On 3-series, insert socket into A/C compressor drive belt tensioner bolt. Compress tensioner by slowly rotating socket clockwise, and remove A/C compressor drive belt. Remove A/C compressor. DO NOT disconnect refrigerant lines.
10. Remove ground strap and right engine mount nut. Remove left engine mount nut. Loosen lower nuts on right/left engine mount. Attach Engine Holding Hoop (00-0-200) and Sling (00-0-204) to engine carrier. Raise engine as far as possible. Ensure wiring harness, ducts and hoses are not stretched or pinched.
11. On all models, remove oil pan bolts. Lower oil pan. Turn sprocket nut clockwise, and pull oil pump sprocket off splines. Remove bolts and oil strainer. Remove bolts and oil pump. Remove oil pan by pulling it rearward.

1. To install, reverse removal procedure. Use Elastic Sealing Compound (3 Bond 1027B) to fill joints between oil pan and front timing case and rear cover.
2. Tighten oil pump sprocket nut counterclockwise. Nut uses left-hand threads. Ensure serpentine belt is correctly routed and properly seated in grooves. Turn 32-mm Wrench (11-5-040) counterclockwise, and tighten cooling fan nut. See «TORQUE SPECIFICATIONS»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl__torque-specifications) .

Valves & Valve Springs

1. Remove cylinder head and camshaft. Remove valve springs, spring retainers and valve stem oil seals.
2. Determine valve seat depth by inserting valve in corresponding valve guide, measuring protrusion from tip of valve stem to valve guide, and noting distance.
3. Machine valve seat. See VALVE SEATS. Insert same valve again, and measure protrusion from valve stem to valve guide, noting distance. Difference between readings is amount of machining.

Valve Stem Oil Seals

Pull off valve stem oil seal. To install oil seals, place Assembly Sleeve (11-1-380) over valve stem. Lubricate valve stem oil seal, and install. Using Assembly Mandrel (11-1-200), press valve stem oil seal against stop.

Valve Guides

1. Insert a NEW valve in valve guide to be checked. End of valve stem must be flush with valve guide. Place dial indicator tip on side of valve head. Wobble valve from side-to-side to measure valve guide wear. Maximum tilt is 0.020" (0.50 mm).
2. If necessary, ream valve guide, and install a replacement valve with an oversize stem diameter of 0.004" (0.10 mm) or 0.008" (0.20 mm). Press reamer guide (cone) on valve seat, and ream out valve guide from combustion chamber side. Ream guide only once. Machine valve seat after reaming valve guide.

Valve Seats

1. Machine valve seats using Valve Seat Lathe (00-3-520) and Valve Seat Reseating Set (00-3-580), following instructions supplied with tools. After machining valve seat angle, produce valve seat diameter "B" and valve seat width "D" by machining correction angles "D" and "E" and countersinking "C". (Scheme 29) See «VALVE SEAT CORRECTION ANGLES»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl) table.
2. If more than 0.008" (0.20 mm) is machined off valve seat, install a valve with a thicker valve head. Valve heads are available in.008" (.20 mm) increments. Valve stems are available in.004" (.10 mm) increments.

Valve Seat Correction Angles

See VALVE SEATS. See VALVE SEAT CORRECTION ANGLES table.

VALVE SEAT CORRECTION ANGLES (1)

Scheme 29

Cylinder Head Height

1. Check flatness of cylinder head using a 0.0012" (0.03 mm) feeler gauge and straightedge. If necessary, machine cylinder head.
2. Ensure cylinder head height exceeds minimum cylinder head height. See «CYLINDER HEAD»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl) table under ENGINE SPECIFICATIONS.

Note. A .012" (0.30 mm) thicker cylinder head gasket is available for machined cylinder heads.

Piston & Rod Assembly

1. Install piston, connecting rod and bearings in corresponding cylinder. Connecting rods and bearing caps have numbers stamped on them. Ensure arrows on top of pistons point toward front of engine.
2. Lubricate connecting rod bearings with oil. Install bearing caps, ensuring numbers match and are aligned. Install and tighten NEW connecting rod bolts. Using Torque Angle Gauge (11-2-110), tighten connecting rod bolts an additional torque angle. See «TORQUE SPECIFICATIONS»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl__torque-specifications) .

Note. If piston and connecting rod assembly have been separated, ensure piston is installed with arrow pointing toward right when connecting rod numbers are facing you.

Fitting Pistons

1. Measure piston diameter about 33/64" (13 mm) from lower edge of piston skirt. Set dial indicator to zero using measured piston diameter.
2. Measure cylinder bore diagonally at bottom, middle and top of bore. Piston-to-cylinder wall clearance should be within specification. See «PISTONS, PINS & RINGS»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl) table under ENGINE SPECIFICATIONS.

Piston Rings

1. Measure piston ring end gaps. See «PISTONS, PINS & RINGS»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl) table under ENGINE SPECIFICATIONS. Install piston rings with word TOP facing up (top of piston crown). (Scheme 30)
2. Position piston ring gaps 120 degrees apart from each other, but DO NOT position gaps above piston pin eye. Measure piston ring side clearances.

Scheme 30

Connecting Rod & Bushing

1. Check connecting rod for parallelism and distortion. If connecting rod replacement is necessary, use only connecting rods of same weight.
2. Piston pin should pass through connecting rod bushing using only thumb pressure. If necessary, replace bushing. Press in bushing with gaps located at 135 degrees or 225 degrees from top. Ream out connecting rod bushing to 0.8662-0.8665" (22.0005-22.010 mm).

Rod Bearings

Select connecting rod bearing shells matching color code on connecting rod. Use Plastigage to check connecting rod bearing oil clearance. See ENGINE SPECIFICATIONS . Install new bearing shells or bearing shells with a different color code to correct oil clearance.

Crankshaft & Main Bearings

1. Main bearing caps are marked for location. Bearing cap No. 6 (thrust bearing) has a shoulder on side of cap. Ensure oil spray jets are installed in oil passages for bearings No. 2, 3, 4, 5, 6 and 7.
2. Use Plastigage to check connecting rod bearing oil clearance. See «ENGINE SPECIFICATIONS»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl__engine-specifications) . Install new bearing shells or bearing shells with a different color code to correct oil clearance.
3. Install upper bearing shells having same color code as dot on bearing support in crankcase. Install lower bearing shells having same color code as dot on crankshaft throw. Ensure grooves of bearing shell guide are located on same side. Tighten lubricated main bearing cap bolts. See «TORQUE SPECIFICATIONS»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl__torque-specifications) .

Note. Reground crankshafts are marked with Yellow, Green or White paint. See CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS table under ENGINE SPECIFICATIONS.

Thrust Bearing

Bearing cap No. 6 has a shoulder on side of cap. Ensure thrust bearing and bearing cap No. 6 are installed in same location.

ENGINE LUBRICATION SYSTEM

Oil pump is a rotary-type oil pump. Oil pump is bolted to engine block and driven directly from crankshaft by a single-roller chain and tensioner. (Scheme 31) Oil filter is mounted vertically on intake side of engine.

Oil Capacity

Oil change amount including filter is 7.0 qts. (6.5L).

Oil Pressure

Oil pressure should be more than 7 psi (.5 kg/cm 2 ) at idle and 56 psi (4.0 kg/cm 2 ) at 3000 RPM.

Scheme 31

OIL PUMP

Note. A chain tensioner is used on oil pump drive chain. Tensioner is located next to crankshaft sprocket.

Removal & Disassembly

1. Remove oil pan. See «OIL PAN»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl) under REMOVAL & INSTALLATION. Turn oil pump sprocket nut clockwise to remove nut. Nut uses left-hand threads.
2. Carefully remove sprocket and chain. Remove oil pump. Locate oil pressure relief valve on oil pump housing. Lightly press down on oil pressure relief valve spring, and remove snap ring.
3. Remove oil pressure relief valve components. Remove oil pump pick-up tube. Remove pump shaft/rotor assembly. (Scheme 31)

Inspection

1. Measure pump body-to-outer rotor clearance. Clearance should be 0.004-007" (0.10-0.18 mm). Measure pump body-to-outer (inner) rotor axial clearance. Clearance should be 0.002-0.003" (0.05-0.08 mm).
2. Inspect oil pressure relief valve components for wear and damage. (Scheme 31) Measure length of unloaded relief valve spring. Spring length should be 3.31" (84.1 mm).

Reassembly & Installation

To reassemble oil pump, reverse disassembly procedure. A gasket is used between oil pump housing and pick-up tube. Tighten oil pump sprocket nut counterclockwise.

VALVE TRAIN SERVICING PRECAUTIONS

1. If camshafts will be removed and installed without removing cylinder head from engine, turn crankshaft in normal direction of rotation about 30 degrees from TDC. This will keep valves from hitting pistons.
2. Install camshafts with lobes for cylinder No. 1 facing each other. Use Camshaft Locating Fixture (11-3-240) to align and hold camshafts. (Scheme 32)or (Scheme 3). NOTE: Always wait specified time between installation of camshaft and installation of cylinder head. See «CYLINDER HEAD INSTALLATION WAITING TIMES»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl) table. CYLINDER HEAD INSTALLATION WAITING TIMES Temperature °F (°C) Minutes 68 (20) 4 50-68 (10-20) 11 32-50 (0-10) 30
3. Wait recommended time to permit hydraulic cam followers to compress. See «CYLINDER HEAD INSTALLATION WAITING TIMES»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl) table. Turn crankshaft back to TDC position.
4. Use TDC Aligning Plug (11-2-300) to hold crankshaft in TDC position. Install timing chain. Remove camshaft and crankshaft holders. Wait at least 10 minutes before cranking engine. See «ENGINE CRANKING WAITING TIMES»(/bmw/z3/e36-1995-2000/remont/mechanical/#engine-repair-6-cyl) table.

Note. Engine may be cranked only after waiting specified time after installation of camshaft and timing chain. See ENGINE CRANKING WAITING TIMES table.

ENGINE CRANKING WAITING TIMES

Scheme 32

TORQUE SPECIFICATIONS

TORQUE SPECIFICATIONS

ENGINE SPECIFICATIONS

GENERAL SPECIFICATIONS

CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS

CRANKSHAFT, MAIN & CONNECTING ROD BEARINGS

CONNECTING RODS

CONNECTING RODS

PISTONS, PINS & RINGS

PISTONS, PINS & RINGS

CYLINDER BLOCK

CYLINDER BLOCK

VALVES & VALVE SPRINGS

CYLINDER HEAD

CYLINDER HEAD

CAMSHAFT

VALVE LIFTERS

VALVE LIFTERS

See also:
• TORQUE SPECIFICATIONS
• INTAKE MANIFOLD
• VALVE TRAIN SERVICING PRECAUTIONS
• ENGINE SPECIFICATIONS