Is it safe to drive my BMW Z3 with a broken engine mount bracket?

I would check the engine mounts and any shock absorbers for the engine.

Only if you wear your seat belt, as the vehicle could come to a sudden unexpected stop as it sheds moving parts while you are driving down the road. Don't forget to stop and pick up your axles and engine, you will need them to make it to your destination.
No really, fix the engine mount before something really bad happens.

SOUNDS very plausible ,have had it happen on bmw a few times ,would recommend buying bracket re-assembling and running vehicle and checking all other pulleys that run on the serpentine belt carefully for wear or noise as it is usually a vibration/loose brackets that cause a mounting bracket to crack or fail ,sorry cant help you on costs or availability ,it often changes with dealerships

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Remove Harmonic Pulley

If necessary, remove drive belt and belt pulley for the air

conditioning compressor.

Remove drive Belt or alternator, refer to Drive Belts, Mounts,

Brackets and Accessories.

Attach Special Tool II 2 150 in conjunction with Special Tool il

2410.

Note:

Protect engine bracket from damage.

Insert wood between engine support and Special Tool 11 2

150.

Unscrew central bolt.

Replace crankshaft radial sealing ring, refer to Front Crankshaft

Seal, Service and Repair.

Installation:

Position the vibration damper in such a way that groove and

Woodruff key are aligned.

Replace central screw.

Tightening torque, refer to Engine. Specifications.

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Refer to Service Precautions. See: Batten'/Service Precautions/Vehicle Damage

Warnings

- Read fault memory.

- Disconnect battery ground wire.

- Remove air cleaner upper section with air-flow sensor.

- Remove alternator drive belt.

With hydraulic drive belt tensioner:

- Remove guide pulley.

Installation

- Fit screw in thread (1) of upper reversing roller.

With mechanical drive belt tensioner

Unfasten screw (1) in upper reversing roller.

Installation:

- Fit screw in thread (2) of upper reversing roller (1). Thread (3) remains exposed.

- Unfasten screw connection at top and bottom of alternator.

Installation:

- To facilitate assembly, push press-mounted bushes (1) on engine carrier into

position (2).
Remove cover cap.

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try the engine breather pipes first ,if that doesnt work clean the idle control valve

1999 BMW 328I 2.8L EFI DOHC 6cyl

Starter - Removal & Installation

The starter motor on some models is very difficult to see from the top of engine compartment as it is covered by the intake manifold. On these models, without removing the intake manifold, the starter motor must be removed from underneath the vehicle. Because the starter motor mounting bolts are not easy to access, a long extension with a universal joint mounted on a proper sized socket could be used. A three foot transmission extension is commercially available from tool vendors that has a 3 / 8 inch drive of the driven end and 1 / 2 inch drive on the drive end. If used with a non-binding impact universal joint and a proper fitting impact socket, the starter motor fasteners can be removed from underneath the vehicle.
Once the starter motor fasteners are removed, the starter motor may have to be moved side-to-side several times to loosen the dowel pin if it has corroded in place.

NOTE When the battery is disconnected, the radio code, on-board computer and clock settings will be lost. The radio code should be obtained before disconnecting the battery or radio. Once the battery has been reconnected, the radio will not function unless the code is keyed in.
Starter motor electrical terminal fastener torque specifications for all models:
M5 terminal fasteners: 44 inch lbs. (5 Nm)
M6 terminal fasteners: 53 inch lbs. (6 Nm)
M8 terminal fasteners: 115 inch lbs. (13 Nm)
Starter motor mounting fasteners:
Hex head bolts: 36 ft. lbs. (49 Nm)
Torx bolts: 32 ft. lbs. (43 Nm) Starter motor electrical terminal fastener torque specifications for all models:
M5 terminal fasteners: 44 inch lbs. (5 Nm)
M6 terminal fasteners: 53 inch lbs. (6 Nm)
M8 terminal fasteners: 115 inch lbs. (13 Nm) Starter motor mounting fasteners:
Hex head bolts: 36 ft. lbs. (49 Nm)
Torx bolts: 32 ft. lbs. (43 Nm) E36 6-Cylinder Engines
Automatic Transmission Models

1. Before servicing the vehicle, refer to the Precautions section.
2. Set the ignition switch to the OFF position.
3. Disconnect the negative battery cable.
4. Remove the climate control air intake duct at the rear of the engine compartment as follows:
   1. Release the grille clips at the rear and lift the grille upward from the rubber seal, then remove the seal.
   2. Remove the two self tapping Phillips screws from inside the duct to release the electrical harness housing.
   3. Press the electrical housing downward to expose and remove the two hex head self tapping screws on each side of the duct and lift the duct up and out of the engine compartment.
5. Remove the intake manifold trim and valve cover trim covers.
6. Disconnect the ignition coil electrical connectors and ground straps, label for reinstallation and place aside.
7. Remove the two fasteners that secure the fuel injection electrical connector harness to the rail. Remove the harness and carefully place aside toward the back of the engine compartment behind the right side strut tower.
8. Remove the intake manifold.
9. Remove the electrical leads from the starter motor and place aside.
10. Remove the starter motor mounting fasteners at the transmission bell housing, then remove the two mounting nuts at the L-shaped mounting bracket.
11. Loosen the L-shaped bracket to engine block mounting bolt slightly, then remove the bolt while supporting the starter motor.
12. Remove the bracket, then lift the starter motor upward away from the engine.
13. Visually inspect the starter pinion and ring gears for any signs of damage.
14. Installation is in reverse order of removal.

Manual Transmission Models

1. Before servicing the vehicle, refer to the Precautions section.
2. Set the ignition switch to the OFF position.
3. Disconnect the negative battery cable.
4. Raise and safely support the vehicle.
5. Remove the fasteners for the reinforcement mounted between the frame rails just behind the rear lower control arm bushing brackets. Mark the bar-s direction for proper reinstallation and remove the bar.
6. Remove the fuel line cover located near the left side rear lower control arm bushing bracket.
7. Release the fuel lines and reverse light wiring from their routing brackets.
8. Note the routing of the starter motor electrical wires, remove the wire mounting nuts, and place the wires aside.
9. Remove the top and bottom starter motor to engine-transmission mounting fasteners.
10. Remove the two mounting nuts at the L-shaped mounting bracket.
11. Loosen the L-shaped bracket to engine block mounting bolt slightly, then remove the bolt while supporting the starter motor.
12. Remove the bracket and carefully lower the starter motor downward away from the engine.
13. Visually inspect the starter pinion and ring gears for any signs of damage.
14. Installation is in reverse order of removal.

Fig. A view of the starter motor mounting fasteners and dowel pin. The mounting bolts are threaded into the starter motor



Fig. The starter motor mounting bolts are a different size than the transmission-to-engine mounting bolts



I hope help you with this (rated this help) Good luck.

3.0 Coupe

Removing and installing complete water pump (M52 / S52 /M52TU/ M54 / M56)

Remove alternator drive belt, refer to Engine, Cooling and Exhaust - Engine - Drive Belts, Mounts, Brackets and Accessories - Drive Belt - Service and Repair - Procedures See: Engine\Drive Belt\Service and Repair
Note: M52/S52 The water drain plug is located on the exhaust side between cylinders 4 and 5 in the engine block (illustration).
M52TU / M54 / M56 The water drain plug is located on the exhaust side on cylinder 2 in the engine block.
Drain and dispose of coolant.

Installation:
Replace seal.
Tightening Torque, refer to Specifications - Mechanical. See: Specifications
Vent cooling system and check for leaks, refer to Engine, Cooling and Exhaust - Cooling System - Service and Repair - Procedures. See: Service and Repair
Release belt pulley,Release water pump.,Tighten two screws (M6) into thread of water pump and water pump out of timing case.

Installation:
Replace O-ring and coat with coolant as anti-friction agent.

2.5L Roadster
SAME PROCEDURE FOR PICTURES Email Me @ aol.com

There should be an engine data plate or sticker somewhere under the hoood.

Have a look inside the rear bumper , there is a vibration damper mounted that is bolted on to the body , this makes the noise .