Why would I see coolant leaking from a motor mount bolt

It's unlikely that there is a freeze plug in that area. The most common sources of coolant leaks on BMW E46 3-Series models are the expansion tank and the radiator. However, there are a few other possibilities that could cause a leak in that area:

1. Heater Core: The heater core is located inside the dashboard and circulates hot coolant to provide heat to the interior of the car. If the heater core is leaking, coolant can drip down onto the motor mount.
2. Coolant Pipe: There is a coolant pipe that runs along the left side of the engine and connects the engine block to the heater core and radiator. If this pipe is corroded or damaged, it can leak coolant onto the motor mount.
3. Head Gasket: A failing head gasket can cause coolant to leak externally from the engine. While this is less common, it's worth checking to see if there are any signs of coolant leaking from the head gasket.

It's recommended to have the coolant system inspected by a qualified mechanic to determine the source of the leak and to make the necessary repairs.

most likely a welsh plug leaking and running down on the mount
pressure test the cooling system and watch for where the coolant is coming from

Blower Motor Removal & Installation W/O Air Conditioning Blower Motor (W/O Air Conditioning)

To Remove:

1. Remove the PCM.
2. Remove the coolant reservoir.
3. Remove the rear coolant recovery reservoir mounting stud.
4. Disconnect the cooling tube from the blower motor.
5. Disconnect the electrical connector from the blower motor.
6. Remove the blower motor mounting bolts.
7. Remove the blower motor insulating cover.
8. Remove the blower motor.

To Install:

1. Install the blower motor.
2. Install the blower motor mounting bolts.
3. Connect the electrical connector to the blower motor.
4. Connect the cooling tube to the blower motor.
5. Install the rear coolant recovery reservoir mounting stud.
6. Install the coolant reservoir.
7. Install the PCM.

W/ Air Conditioning Blower Motor (W/ Air Conditioning)

To Remove:

1. Remove the PCM.
2. Remove the coolant reservoir.
3. Remove the rear coolant recovery reservoir mounting stud.
4. Disconnect the electrical connector from the blower motor.
5. Move the PCM connectors out of the way.
6. Remove the blower motor access cover screws. CAUTION
   Do not cut any deeper than necessary in order to remove the access cover.
   
7. Cut through the access cover on the cut line using a sharp utility knife.
8. Disconnect the cooling tube from the blower motor.
9. Remove the blower motor mounting bolts.
10. Remove the blower motor.

To Install:

1. Install the blower motor.
2. Install the blower motor mounting bolts.
3. Connect the cooling tube to the blower motor.
4. Install the blower motor access cover.
5. Install the blower motor access cover retaining screws.
6. Using black weather-strip adhesive, seal the cut line.
7. Connect the blower motor electrical connector.
8. Reposition the PCM connectors.
9. Install the rear coolant recovery reservoir mounting stud.
10. Install the coolant reservoir.
11. Install the PCM.

Water Pump REMOVAL & INSTALLATION CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old. 1987-95 Vehicles EXCEPT 1995 VIN 1 ENGINE

1. Disconnect the negative battery cable.
2. Drain cooling system into a suitable container.
3. Remove the serpentine drive belt, as outlined in Section 1 of this manual. NOTE: On some engines, removing the alternator provides better clearance for removing the water pump. For alternator removal and installation procedures, please refer to Section 2 of this manual. Fig. 1: After removing the alternator, remove the brace
   
   
4. Unfasten the water pump pulley bolts, (long bolt removed through access hole provided in the body side rail), then remove the pulley. Fig. 2: Pull the water pump pulley from the pump
   
   
5. Disconnect the radiator and heater hoses from water pump. Fig. 3: Use a screwdriver to loosen the hose clamp screws, then disconnect the hoses from the water pump
   
   
6. For 1992-95 vehicles, remove the torque axis mount, as follows:
   1. Use a suitable engine support fixture and lifting bracket to raise the engine slightly to take the weight off of the engine mounts.
   2. Remove the through-bolt from the torque axis (front) engine mount.
   3. Lift the engine with the support fixture until the power steering reservoir touches the strut tower cross brace.
   4. Loosen the bottom two bolts on the torque axis (front) engine mount.
   5. Remove the A/C line clip and top two bolts on the torque axis engine mount, then remove the mount.
   6. Remove the 2 bolts and nut attaching the engine torque axis mount bracket assembly to the front of the engine. NOTE: On some engines, when you remove the 13mm bolts, coolant will flow from the bolt holes, so make sure to position a drain pan under the pump before unfastening the bolts.
      
7. Remove the water pump attaching bolts, then remove the water pump from the vehicle. Remove and discard the gasket. Thoroughly clean the gasket mating surfaces. Fig. 4: Unfasten the water pump mounting bolts (see arrows for locations of top bolts) . . .
   Fig. 5: . . . then remove the water pump from the engine
   Fig. 6: Use a gasket scraper to carefully clean the water pump's mating surface
   Fig. 7: You can also use Scotchbrite® or equivalent non-abrasive scouring pad to clean the water pump gasket mating surface
   Fig. 8: When using a scraper to clean the gasket mating surfaces, be careful not to gouge the engine and cause leaks
   Fig. 9: Exploded view of the water pump mounting - 1994 vehicle shown, others similar
   To install:
   
8. Apply a suitable sealant to the bolt threads. Fig. 10: Coat the bolt threads with a suitable sealing compound
   
   
9. Position a new gasket, then install the water pump to the engine and tighten the retaining bolts, as follows: Fig. 11: Place a new gasket on the water pump mounting surface
   
   1. For 1987-94 vehicles, tighten the long bolts to 29 ft. lbs. (39 Nm) and the short bolts to 97 inch lbs. (11 Nm).
   2. For 1995 vehicles, tighten the water pump-to-block bolts to 22 ft. lbs. (30 Nm) and the water pump-to-front cover bolts to 11 ft. lbs. (15 Nm), plus an additional 80°rotation.
10. For 1992-95 vehicles, install the torque axis mount, as follows:
    1. Attach the torque axis engine mount bracket assembly to the front of the engine using the 2 bolts and nut. Fig. 12: Install the torque axis engine mount bracket and secure with the 2 bolts and nut
       
       
    2. Replace the 2 upper bolts previously removed from the torque axis engine mount, and attach the mount and plastic clip for the A/C lines.
    3. Tighten the 2 lower bolts that were previously loosened on the torque axis engine mount. Fig. 13: Exploded view of the torque axis engine mount and tightening specifications
       
       
    4. Adjust the engine height to align the torque mount with the torque axis mount bracket.
    5. Insert the through-bolt, attach the retaining nut and tighten to the specifications shown in the accompanying figure. Remove the engine support and lifting fixture. Fig. 14: Insert the torque axis mount bracket through-bolt
       
    
    
11. Install the water pump pulley and secure with the retaining bolts.
12. Connect the radiator and heater hoses to the water pump.
13. Install the serpentine drive belt.
14. Connect the negative battery cable.
15. Fill cooling system and check for leaks. Start the engine and allow to come to normal operating temperature. Check for leaks and top-off the coolant.

Blower Motor Removal & Installation W/O Air Conditioning Blower Motor (W/O Air Conditioning)

To Remove:

1. Remove the PCM.
2. Remove the coolant reservoir.
3. Remove the rear coolant recovery reservoir mounting stud.
4. Disconnect the cooling tube from the blower motor.
5. Disconnect the electrical connector from the blower motor.
6. Remove the blower motor mounting bolts.
7. Remove the blower motor insulating cover.
8. Remove the blower motor.

To Install:

1. Install the blower motor.
2. Install the blower motor mounting bolts.
3. Connect the electrical connector to the blower motor.
4. Connect the cooling tube to the blower motor.
5. Install the rear coolant recovery reservoir mounting stud.
6. Install the coolant reservoir.
7. Install the PCM.

W/ Air Conditioning Blower Motor (W/ Air Conditioning)

To Remove:

1. Remove the PCM.
2. Remove the coolant reservoir.
3. Remove the rear coolant recovery reservoir mounting stud.
4. Disconnect the electrical connector from the blower motor.
5. Move the PCM connectors out of the way.
6. Remove the blower motor access cover screws. CAUTION
   Do not cut any deeper than necessary in order to remove the access cover.
   
7. Cut through the access cover on the cut line using a sharp utility knife.
8. Disconnect the cooling tube from the blower motor.
9. Remove the blower motor mounting bolts.
10. Remove the blower motor.

To Install:

1. Install the blower motor.
2. Install the blower motor mounting bolts.
3. Connect the cooling tube to the blower motor.
4. Install the blower motor access cover.
5. Install the blower motor access cover retaining screws.
6. Using black weather-strip adhesive, seal the cut line.
7. Connect the blower motor electrical connector.
8. Reposition the PCM connectors.
9. Install the rear coolant recovery reservoir mounting stud.
10. Install the coolant reservoir.
11. Install the PCM.

REMOVE OR DISCONNECT

1. Negative cable at the battery.
2. Drain the coolant system.
3. drive belt .
4. Coolant hoses at the coolant pump.
5. Coolant pump pulley bolts (long bolt removed through access hole provided in the body side rail), then remove the pulley
6. Torque axis mount.
7. Coolant pump attaching bolts and pump.
8. Clean all gasket mating surfaces.
9. 

INSTALL OR CONNECT

1. Using a new gasket, install the coolant pump on the engine.

• Tighten long bolts to 30 Nm (22 lbs. ft.). and short bolts to 18 Nm (13 lbs. ft.)
• Torque axis mount.

• Tighten bolt to 87 Nm (65 lbs. ft.)

1. Coolant pump pulley.

• Tighten bolts to 15 Nm (11 lbs. ft) .

1. Coolant hoses onto the pump.
2. install drive belt .
3. Fill the coolant system.
4. Connect the battery, then start the engine
5. Check for coolant leaks.

This how it is done step by step.
Remove the mounting bolts from the coolant expansion tank and lift the expansion tank out of the engine compartment. Tip: Do not disconnect the hoses from the coolant expansion tank. Label and disconnect the electrical connectors from the starter motor. Remove the mounting nuts from the starter motor and lift the starter motor off the bellhousing. Using a flashlight, inspect the flywheel teeth (through the opening in the bell housing) while an assistant turns the engine over by hand. You should replace the flywheel if any teeth are missing, cracked, or chipped. Tip: To turn the engine over by hand, turn the harmonic balancer bolt clockwise with the correct socket and 1/2 inch ratchet. Install the new starter motor on the bellhousing and tighten the mounting nuts. Connect the electrical connectors to the starter motor. Re-install the expansion tank and tighten the mounting bolts. Reconnect the negative battery cable.

Nissan Car 350Z & Maxima 1999-06 Radiator - Removal & Installation

1. Before servicing the vehicle, refer to the precautions in the beginning of this section.
2. Drain the cooling system.
3. Remove or disconnect the following:
   Negative battery cable Coolant reservoir tank and bracket Upper mounting bracket Upper radiator hose Oil cooler lines, if equipped Lower radiator hose Cooling fan and condenser fan Fan motors and shields Radiator

To install:

1. Install or connect the following:
   Radiator Fan motors and shields Cooling and condenser fans and torque the bolts to 44 inch lbs. (5 Nm) Lower radiator hose Oil cooler lines, if equipped Upper radiator hose Upper mounting bracket Coolant reservoir tank and bracket and torque the bolt to 44 inch lbs. (5 Nm) Negative battery cable
2. Fill the cooling system to the proper level.
3. Start the vehicle, check for leaks and repair if necessary.

WARNING Do not remove radiator cap when engine is hot. Serious burns could occur from high-pressure engine coolant escaping from radiator. Wrap a thick cloth around the cap. Slowly turn it a quarter of a turn to release built-up pressure. Carefully remove radiator cap by turning it all the way.

1. Before servicing the vehicle, refer to the Precautions section.
2. Drain the cooling system.
3. Remove or disconnect the following:
   Negative battery cable Coolant reservoir tank and bracket Upper mounting bracket Upper radiator hose Oil cooler lines, if equipped Lower radiator hose Cooling fan and condenser fan Fan motors and shields Radiator
   

To install:

1. Install or connect the following:
   Radiator Fan motors and shields Cooling and condenser fans and torque the bolts to 44 inch lbs. (5 Nm) Lower radiator hose Oil cooler lines, if equipped Upper radiator hose Upper mounting bracket Coolant reservoir tank and bracket and torque the bolt to 44 inch lbs. (5 Nm) Negative battery cable


2. Fill the cooling system to the proper level.
3. Start the vehicle, check for leaks and repair if necessary.

WARNING Do not remove radiator cap when engine is hot. Serious burns could occur from high-pressure engine coolant escaping from radiator. Wrap a thick cloth around the cap. Slowly turn it a quarter of a turn to release built-up pressure. Carefully remove radiator cap by turning it all the way.


Fig. Exploded view of radiator and components

1. Before servicing the vehicle, refer to the Precautions section.
2. Drain the cooling system.
3. Remove or disconnect the following:
   CAUTION Do not damage or scratch the A/C condenser and radiator core while removing.
   CAUTION Because A/C condenser is onto the front-lower portion of radiator, moving to rear direction should be at minimum.
   Negative battery cable Engine cover Air duct and air cleaner case assembly Bracket mounting bolt for anchoring A/C piping Reservoir tank and bracket Upper and lower radiator hoses Radiator cooling fan assembly On A/T models, A/T fluid cooler hoses. Plug hoses to avoid leakage Cover, then two A/C condensing mounting bolts located in the upper part of the radiator Rotate two radiator upper mount brackets 90 degrees in the direction shown in the illustration and remove
   
   Fig. Removing A/C condensing mounting bolts
   
   
   
   Fig. Rotating radiator upper mount brackets 90 degrees
   
   
   
   Fig. Removing radiator
   
4. Remove the radiator by performing the following:
   CAUTION Lifting A/C condenser should be minimum to prevent a load to A/C piping.
   With lifting and pulling radiator in a rear direction, disassemble lower mount from radiator core support center. Lift A/C condenser up and remove radiator after disengaging the fitting as front-bottom surface After removing radiator, put A/C condenser on radiator core support center to prevent a load to A/C piping, and temporarily fix it with rope or similar means

To install:

1. To install, reverse removal procedure.
2. Check radiator cap for any leaks.
3. Start and warm up engine. Check for engine coolant leaks and A/T fluid leaks.

Hope this help (remember comment and rated this).

Removal
1. Support the vehicle on jack stands.
2. Disconnect the negative battery cable.
3. Drain the cooling system.
4. Remove water pump drive belt.
5. Disconnect the coolant hoses at the water pump.
6. Remove the water pump pulley bolts (long bolt removed through the access hole provided in
the body side rail), then remove the pulley.
7. Remove the torque axis mount. See TORQUE AXIS ENGINE MOUNT .
8. Remove the water pump attaching bolts and pump.
9. Clean all gasket mating surfaces.



Installation
1. Using a new gasket, install the water pump on the engine. Tighten the bolts to
specifications. See TORQUE SPECIFICATIONS .
2. Install the torque axis mount. See TORQUE AXIS ENGINE MOUNT .
3. Install the water pump pulley, then tighten the bolts to specifications. See TORQUE
SPECIFICATIONS .
4. Connect the coolant hoses onto the pump.
5. Install the water pump drive belt.
6. Fill the cooling system.
7. Add coolant supplement tablets.
8. Connect the battery cable, then start the engine.
9. Inspect for coolant leaks.

alfred11s: No, you don't have to lift the motor. You do have to remove the right hand engine mounting insulator.
I will give you the procedure for the removal to access the pump:.
1.Drain engine coolant
2. remove right hand engine mounting insulator
3. Remove #2 and # 3 timing belt covers
4. Remove front engine mounting insulator as follows
a. remove hole cover
b. remove the 2 bolts from the mounting
c. remove the nut, the through-bolt and front engine mounting insulator
5. Remove the electric cooling fan
6.Disconnect engine wire remove the bolt and 2 nuts and disconnect the engine wire.
Water pump removal instructions:
1. Disconnect the crank sensor connector from the dipstick tube
2, Remove the dipstick tube and dipstick (only 1 bolt holds it)
3. Disconnect the water temp sensor from harness
4, Remove the two nuts and the # 2 water inlet from the hose.
5.Remove the three bolts which retain the water pump!
CAUTION! try to keep antifreeze off the timing belt. Put rags down and pack them where the coolant would normally spill.
WELL alfred11s: My answer should be a pleasant surprise.
Print it out and carry it out to the car.
If I've done well, maybe you can comment on what you think