Water Pump Information and Replacement – 2.5L NA

Overview

This procedure outlines the steps to replace the water pump on all Porsche 944 variants with an 8-valve engine, covering pre-1985.5 (83-85.5) and 1985.5 onwards (86-88) models. The water pump circulates coolant to keep the engine at optimal temperatures, and replacement is necessary if it leaks or fails. This guide recommends using the new style water pump for all models, which includes a timing belt guard rail and a larger idler roller for improved reliability.

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

Tools Required

• Floor jack
• Jack stands or ramps
• Drain pan
• Metric socket set (including 10mm (3/8 inch) socket)
• Metric combination wrench set
• Timing Belt Tensioning Tool (P9201)
• Flywheel Lock (P9206)
• Snap ring pliers

Parts Required

• New style water pump (951 106 021 10)
• Water pump gasket (944 106 132 04)
• Block-off plate for NA engines (944 106 313 00)
• O-ring for block-off plate (900 174 049 40 or 999 707 283 40)
• Thermostat for new style pump (944 106 019 00)
• O-ring for new thermostat (944 106 929 08)
• Spacer for new style pump thermostat (900 234 160 00)
• Thermostat snap ring (900 042 025 01)
• For Pre-85.5 models upgrading to new style pump:
• Guard rail (944 105 213 01)
• Guard rail lock nuts (2) (999 084 092 02)
• 46.2mm idler roller (944 105 241 03)
• Bolts 6mm x 20mm (2) (N 014 704 1)
• Washer (2) (N 011 524 7)

Required Additional Procedures

Steps in these procedures are required to complete this process:

• Locating and Setting Engine to Top Dead Center (TDC), Cylinder 1
• Flywheel Lock Installation
• Camshaft Belt Removal
• Coolant System Draining, Filling, and Venting
• Camshaft Belt Installation
• Air Filter Housing and Air Flow Sensor – Installation

Step-by-Step Procedure

Step 1: Prepare the Vehicle

1. Place the car on jack stands or ramps to ensure safe access to the engine bay.
2. Disconnect the positive battery lead to prevent electrical issues during the procedure.

Step 2: Set Engine to Top Dead Center (TDC)

3. Follow this link to ensure this step – Locating and Setting Engine to Top Dead Center (TDC), Cylinder 1 – is completed accurately to align the engine correctly.

Step 3: Install Flywheel Lock

4. Follow this link to ensure this step – Flywheel Lock Installation – is completed accurately, using the Flywheel Lock (P9206) to secure the engine.

Step 4: Remove Timing Belt and Components

5. Follow this link to ensure this step – Camshaft Belt Removal – is completed accurately, removing the timing belt, rollers, crankshaft gear, and rear timing cover.

Tip: Inspect the crankshaft oil seal for leaks or wear and replace if necessary (944 101 173 00).

Step 5: Drain Cooling System

6. Follow this link to ensure this step – Coolant System Draining, Filling, and Venting – is completed accurately, draining the coolant into a suitable catch pan.
7. Disconnect the coolant hoses from the water pump.

Step 6: Remove Old Water Pump

8. Loosen the water pump retaining bolts and nuts using a 10mm (3/8 inch) socket.
9. Remove the water pump from the engine bay.

Step 7: Install Thermostat on New Water Pump

10. Install the thermostat (944 106 019 00) on the new water pump (951 106 021 10) using the snap ring (900 042 025 01) from the old pump.

For Pre-85.5 models upgrading to new style pump:
The new style pump has a 7mm gap between the thermostat sealing surface and snap ring groove. Install the 2.5mm spacer (900 234 160 00) between the snap ring and thermostat, along with the new thermostat O-ring (944 106 929 08).

For 85.5 Onwards models:
The new style pump is standard, requiring the new thermostat and O-ring without additional modifications.

Step 8: Install Block-Off Plate

11. Install the block-off plate (944 106 313 00) with its O-ring (900 174 049 40 or 999 707 283 40) on the new water pump.

If the new pump has two bolt holes, transfer the 6mm stud from the old pump or use two 6mm x 20mm bolts (N 014 704 1) with washers (N 011 524 7).

Step 9: Install New Water Pump

12. Install the new water pump with a new gasket (944 106 132 04), typically supplied with the pump.

For Pre-85.5 models upgrading to new style pump:
Modify the rear timing cover to accommodate the guard rail (944 105 213 01) and install it with lock nuts (999 084 092 02).
Install the 46.2mm idler roller (944 105 241 03).

13. Tighten the water pump nuts and bolts to 8 Nm (6 ft-lbs) using a 10mm (3/8 inch) socket. Apply Loctite 270 to nuts but not bolts to avoid stripping during future removal.

Step 10: Reassemble Timing Belt and Components

14. Follow this link to ensure this step – Camshaft Belt Installation – is completed accurately, installing the timing belt and rollers.
15. Adjust the timing belt tension according to the Porsche 944 Workshop Manual.

Step 11: Reinstall Air Filter Assembly

16. Follow this link to ensure this step – Air Filter Housing and Air Flow Sensor – Installation – is completed accurately.

Step 12: Final Reassembly and Coolant Fill

17. Reconnect the positive battery lead.
18. Follow this link to ensure this step – Coolant System Draining, Filling, and Venting – is completed accurately to fill and vent the cooling system.
19. Reinstall the skid pan.
20. Remove the car from jack stands or ramps.

Post Procedure Checklist

• Verify the engine is still at TDC to ensure proper timing belt alignment.
• Check for coolant leaks around the water pump and hoses.
• Inspect the timing belt for proper tension and condition, replacing if worn or damaged.
• Ensure all tools and debris are removed from the engine bay.

Sources

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