Engine Installation – 2.5L NA

Overview

This guide outlines the procedure for installing an 8-valve engine in a Porsche 944, covering pre-1985.5 (1983–1985.5) and 1985.5 onwards (1986–1988) variants. The process involves raising the engine into the vehicle, securing it to the cross-member, and reconnecting all necessary components. Proper installation ensures reliable engine performance and vehicle operation. This guide assumes the engine is installed from below, with the steering rack and cross-member already removed, as per the removal process.

Pink and blue text represent links to additional resources, tools, parts, and partner websites.

Tools Required

• Jack stands
• Floor jack
• Hose clamps or locking pliers
• Metric socket set (10mm, 13mm, 17mm, 19mm)
• Metric wrench set (10mm (3/8 inch), 13mm (1/2 inch), 17mm (11/16 inch), 19mm (3/4 inch))
• Phillips and flat tip screwdriver set
• Engine hoist
• Diagonal cutters
• Clutch alignment tool (manual transmission)

Parts Required

• Torque tube to clutch housing bolts (4, M10 x 35mm): 944 423 010 00
• Upper motor mount bolts (4, 8mm, length per motor mount replacement procedure): 999 072 003 02
• Lower motor mount bolts (10mm): 999 072 004 02
• Cross-member mounting bolts (12mm): 999 072 005 02
• Control arm to cross-member lock nut (12mm): 999 084 010 02
• Rear control arm mounting bracket bolts (10mm): 999 072 006 02
• Steering knuckle lock nut (10mm): 999 084 011 02
• Stabilizer to control arm lock nut (10mm): 999 084 012 02
• Stabilizer bracket to body bolts (8mm): 999 072 007 02

Required Additional Procedures

Steps in these procedures are required to complete this process:

• Motor Mounts Checking
• Motor Mount Replacement
• DME Control Unit Installation
• Air Filter Housing and Air Flow Sensor Installation
• Distributor Cap and Rotor Replacement
• Radiator Installation
• Coolant System Draining, Filling, and Venting

Step-by-Step Procedure

Step 1: Prepare the Engine and Vehicle

1. For manual transmission vehicles, if the clutch disc or pressure plate was removed, ensure the clutch disc is aligned with the pressure plate using a clutch alignment tool before installing the bell housing. This should be done prior to engine installation.
2. Verify that the motor mount brackets are securely attached to the engine block.
3. Raise the vehicle on jack stands high enough to slide the engine underneath. Position the engine under the center of the engine compartment.

Step 2: Raise the Engine into Position

4. Attach an engine hoist to the engine’s lifting points (one at the rear of the cam housing, one near the alternator).
5. Raise the engine into the engine compartment, moving it toward the front to clear the drive shaft. When the drive shaft is centered in the clutch housing opening, slide the engine rearward. Gently rock the engine if needed to align the drive shaft, which should insert easily if the clutch is properly aligned.

Step 3: Secure the Torque Tube

6. Install the torque tube flange to clutch housing bolts (4, M10 x 35mm, 944 423 010 00). Tighten to 42 Nm (30 ft-lbs) using a 17mm (11/16 inch) socket.

Step 4: Prepare and Install the Cross-Member

7. Before installing the cross-member, follow this link to ensure this step – Motor Mounts Checking – is completed to verify if motor mounts need replacement.

For Pre-85.5 models:
Use standard motor mounts compatible with 1983–1985.5 models.

For 85.5 Onwards models:
Use updated motor mounts designed for 1985.5–1988 models, which may have different bolt lengths.

8. Install the motor mounts into the cross-member. Install the lower motor mount bolts (10mm, 999 072 004 02) but do not fully tighten.
9. If new motor mounts are installed, follow this link to ensure this step – Motor Mount Replacement – to determine the correct length of upper motor mount bolts (4, 8mm, 999 072 003 02).
10. Using a floor jack, raise the cross-member into position, ensuring the motor mounts align with the engine block brackets.

Step 5: Reconnect the Steering Shaft

11. Slide the steering shaft universal joint onto the steering rack spline inlet before fully raising the cross-member. Ensure correct orientation using marks made during removal. Install the universal joint locking bolt.

Step 6: Secure the Motor Mounts and Cross-Member

12. Install the upper motor mount bolts (8mm, 999 072 003 02) and tighten to 23 Nm (17 ft-lbs) using a 13mm (1/2 inch) socket.
13. Tighten the lower motor mount bolts (10mm, 999 072 004 02) to 32 Nm (24 ft-lbs) using a 17mm (11/16 inch) socket.
14. Install the cross-member mounting bolts (12mm, 999 072 005 02) and tighten to 85 Nm (63 ft-lbs) using a 19mm (3/4 inch) socket.

Step 7: Reinstall Suspension and Steering Components

15. Install the suspension control arms and stabilizer bar. Tighten the control arm to cross-member lock nut (12mm, 999 084 010 02) to 65 Nm (48 ft-lbs). Tighten the rear control arm mounting bracket bolts (10mm, 999 072 006 02) to 46 Nm (34 ft-lbs).
16. Attach the steering knuckle to the control arm ball joint. Tighten the steering knuckle lock nut (10mm, 999 084 011 02) to 50 Nm (37 ft-lbs).
17. Install the front stabilizer bar. Tighten the stabilizer to control arm lock nut (10mm, 999 084 012 02) to 24 Nm (18 ft-lbs). Tighten the stabilizer bracket to body bolts (8mm, 999 072 007 02) to 23 Nm (17 ft-lbs).

Step 8: Reinstall Engine Components

18. Bolt the air conditioning compressor into place.
19. Install the alternator if it was removed.
20. Install the motor mount heat shield.
21. Install the slave cylinder (manual transmission).
22. Install the exhaust system.
23. For USA models (85.5 Onwards), install the oxygen sensor.

Step 9: Reconnect Fuel, Vacuum, and Coolant Lines

24. Attach the fuel supply and return lines.
25. Install the charcoal venting hose.
26. Install the air conditioning fast idle hose.
27. Reconnect all vacuum and coolant hoses.
28. Attach the hose to the heater control valve and the coolant return line from the heater core.

Step 10: Reinstall Power Steering and Starter

29. Install the power steering pump and reconnect its hoses.
30. Install the starter and reconnect its electrical leads.

Step 11: Reconnect Electrical and Ground Connections

31. Route the engine wiring harness through the firewall to the DME control unit.
32. Reconnect all engine grounds, including one near the top of the clutch housing (driver’s side, right-hand drive), one on the engine block, and one on the firewall (inside the engine or battery compartment). Clean all ground connections thoroughly before installation to prevent poor running or DME failure.
33. Connect the brake booster vacuum hose.
34. Connect the throttle cable and, if equipped, the cruise control cable and servo electrical connector.

Step 12: Complete Component Installation

35. Follow this link to ensure this step – Radiator Installation – is completed to install the radiator.
36. Follow this link to ensure this step – Distributor Cap and Rotor Replacement – is completed to install the rotor and distributor cap.
37. Follow this link to ensure this step – Air Filter Housing and Air Flow Sensor Installation – is completed to install the air flow sensor and air filter housing.
38. Secure the engine wiring harness to the firewall using cable ties.
39. Inside the vehicle, follow this link to ensure this step – DME Control Unit Installation – is completed to connect the wiring harness to the DME control unit.

Step 13: Fill Fluids and Final Checks

40. Follow this link to ensure this step – Coolant System Draining, Filling, and Venting – is completed to fill and vent the coolant system.
41. Fill the power steering reservoir with fluid.
42. Check the engine oil level and top off if necessary.
43. Connect the battery leads.
44. Install the fuel pump fuse if it was removed.

Step 14: Test the Vehicle

45. Start the vehicle and let it warm up. Check for leaks in the engine compartment and under the vehicle.
46. Move the steering wheel side to side and check the power steering fluid level, adding fluid as needed.
47. Stop the vehicle, install the skid pan, front wheels, and lower the vehicle from the jack stands.

Post Procedure Checklist

• Check for leaks in the engine compartment and under the vehicle.
• Verify all bolts are torqued to specifications (e.g., motor mount bolts, cross-member bolts).
• Ensure all electrical grounds are clean and secure to prevent DME issues.
• Confirm the power steering fluid level is correct after steering tests.
• Inspect the clutch operation (manual transmission) for smooth engagement.
• Verify the vehicle runs smoothly with no warning lights.

Sources

• Clark’s Garage
• Pelican Parts
• Porsche 944 Workshop Manuals
• YouTube