Camshaft Assembly Oil Seal Replacement

Overview

This procedure outlines the steps to replace the camshaft assembly oil seals and the rear cam housing gasket on a Porsche 944 S2 with a 3.0L 16V engine. The front camshaft seals prevent oil leaks at the camshaft housing, while the rear cam housing gasket addresses common leaks that can develop after approximately 80,467 km (50,000 miles). Proper execution ensures engine integrity and prevents oil contamination. This guide is tailored for the 944 S2, omitting details for other models like the 944 Turbo or earlier variants.

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

Tools Required

• Jack stands
• Floor jack
• Metric socket set (including 10mm (3/8 inch) socket)
• Metric wrench set (including 10mm (3/8 inch) and 32mm (1-1/4 inch) wrenches)
• Porsche Timing Belt Tension Tool (P9201)
• Flywheel Lock (P9206)
• 10mm (3/8 inch) Cheesehead tool or 3mm (1/8 inch) hex key
• Needle nose pliers or diagonal cutters
• Hammer
• Torque wrench (capable of 8 Nm (6 ft-lbs) to 70 Nm (52 ft-lbs))

Parts Required

• Front Main Camshaft Seal: 999 113 349 40 (32 x 40 mm)
• Rear Distributor Housing O-Ring: 999 701 602 40 (50 x 5 mm)
• Rear Distributor Housing Seal (Small): 928 105 184 00
• Spacer Mylar Seal: 944 105 321 00
• Rear Cam Housing Cover Gasket: 928 105 189 02
• Loctite (for connector retaining bolt)
• Engine oil or bearing grease (for seal lubrication)

Required Additional Procedures

Steps in these procedures are required to complete this process:

• Camshaft Belt Removal
• Camshaft Belt Installation
• Camshaft Belt Tension – Checking and Adjusting
• Flywheel Lock Installation
• Locating and Setting Engine to Top Dead Center (TDC), Cylinder 1
• Distributor Cap and Rotor Replacement
• Air Filter Housing and Air Flow Sensor – Removal
• Air Filter Housing and Air Flow Sensor – Installation

Step-by-Step Procedure

Step 1: Prepare the Vehicle and Remove Components

1. Disconnect the negative battery lead to ensure safety during the procedure.
2. Follow this link to ensure this step – Air Filter Housing and Air Flow Sensor – Removal – of the process is followed accurately.
3. Remove the alternator and power steering belts by loosening their tensioners and sliding the belts off.
4. Remove the front timing belt covers to access the camshaft sprocket.
5. Follow this link to ensure this step – Distributor Cap and Rotor Replacement – of the process is followed accurately to remove the distributor cap and rotor.
6. Remove the front distributor housing cover using a 10mm (3/8 inch) socket or wrench.

Step 2: Release Timing Belt Tension

7. The Porsche 944 S2 (1989-1991) uses a spring tensioner for the timing belt. To release tension:For 944 S2 models:

   • Locate the spring tensioner’s front plate, which resembles a triangle.

   • Loosen, but do not remove, the locknut and bolt on the side of the triangle near the tensioning spring using a 10mm (3/8 inch) wrench.

   • Push down on the tensioner lever arm to compress the spring and release belt tension. A balance shaft spanner can assist if available.

   • With the spring compressed, tighten the locknut and bolt to secure the tensioner.

8. Slide the timing belt off the camshaft sprocket carefully to avoid disturbing the sprocket alignment.

Step 3: Remove Camshaft Sprocket Components

9. Remove the connector from the retaining collar:• The camshaft sprocket is secured by a retaining collar, which houses a connector for the ignition rotor.

   • Remove the M5 x 10mm bolt securing the connector using a 10mm (3/8 inch) socket or wrench.

   • Pull the connector straight out. If it’s stuck, gently heat the outside of the collar’s recess to loosen it.

10. Remove the retaining collar bolt:• Locate the M10 x 65mm cheesehead bolt in the retaining collar’s recess.

    • Insert a 10mm (3/8 inch) cheesehead tool into the bolt and tap it with a hammer to “wake” the bolt and prevent stripping.

    • Hold the retaining collar’s flats (32mm or 1-1/4 inch) with a combination wrench at a slight angle to counter torque.

    • Carefully loosen and remove the cheesehead bolt, ensuring the camshaft sprocket does not turn more than a few degrees to avoid valve-piston contact.

11. Slide the retaining collar and camshaft sprocket off the camshaft, keeping them aligned with the woodruff key.

12. Remove the woodruff key from the camshaft slot using needle nose pliers or diagonal cutters.

Step 4: Replace Front Camshaft Seals

13. Remove the rear distributor housing:• Remove the three M6 bolts securing the rear distributor housing to the camshaft housing using a 10mm (3/8 inch) socket or wrench.

    • Slide the rear distributor housing off the camshaft.

14. Inspect and replace seals:• If the spacer remains in the rear distributor housing, it will come out with it. Check for the mylar seal (944 105 321 00) on the camshaft and replace it.

    • If the spacer is still on the camshaft, slide it off and replace the mylar seal.

    • Replace the main camshaft seal (999 113 349 40) in the front of the rear distributor housing.

    • Replace the large O-ring (999 701 602 40) and small round seal (928 105 184 00) in the back of the rear distributor housing.

    • Apply a thin layer of engine oil or bearing grease to all seals before and after installation.

15. Reinstall the rear distributor housing:• Slide the housing with new seals onto the camshaft.

    • Secure with the three M6 bolts and torque to 8 Nm (6 ft-lbs).

Step 5: Reassemble Camshaft Sprocket

16. Insert the woodruff key into the camshaft slot.
17. Slide the camshaft sprocket and retaining collar onto the camshaft, aligning with the woodruff key.
18. Install the M10 x 65mm cheesehead bolt into the retaining collar and torque to 65-70 Nm (48-52 ft-lbs) using a torque wrench and a 32mm (1-1/4 inch) wrench to hold the collar.
19. Reinstall the connector into the retaining collar’s recess.
20. Apply Loctite to the M5 x 10mm connector retaining bolt, install it, and tighten securely.

Step 6: Reinstall Timing Belt and Components

21. Follow this link to ensure this step – Locating and Setting Engine to Top Dead Center (TDC), Cylinder 1 – of the process is followed accurately to verify crankshaft position.
22. Align the camshaft sprocket to TDC using the scribe mark on the sprocket and the mark on the rear distributor housing.
23. Install the timing belt onto the camshaft sprocket, ensuring no slack between the camshaft sprocket and crankshaft gear.
24. Follow this link to ensure this step – Camshaft Belt Tension – Checking and Adjusting – of the process is followed accurately to tension the belt.
25. Reinstall the timing belt covers.
26. Reinstall the alternator and power steering belts, adjusting their tensioners as needed.
27. Follow this link to ensure this step – Air Filter Housing and Air Flow Sensor – Installation – of the process is followed accurately to reinstall these components.
28. Reconnect the negative battery lead.

Step 7: Replace Rear Cam Housing Gasket

29. Locate the rear cam housing cover, which includes the engine lifting ring.
30. If equipped with a TDC sensor, remove the 10mm (3/8 inch) bolt securing the sensor’s electrical connector strap to the lifting ring and move the connector aside.
31. Remove the three M6 x 22mm bolts securing the lifting ring and rear cover using a 10mm (3/8 inch) socket or wrench.
32. Apply a thin coat of bearing grease to both sides of the new rear cam housing gasket (928 105 189 02).
33. Position the gasket onto the rear cam housing cover, then install the cover and lifting ring onto the cam housing.
34. Secure with the three M6 x 22mm bolts and torque to 8 Nm (6 ft-lbs).

Post Procedure Checklist

• Check for oil leaks around the camshaft housing and rear cam housing cover after starting the engine.
• Verify timing belt tension is correct by following the Camshaft and Balance Shaft Belt Tension – Checking and Adjusting procedure.
• Ensure the camshaft sprocket is aligned at TDC and the engine runs smoothly without unusual noises.
• Confirm all bolts are torqued to specifications (8 Nm (6 ft-lbs) for M6 bolts, 65-70 Nm (48-52 ft-lbs) for cheesehead bolt).
• Drive the vehicle 5 miles (8 km) and recheck for leaks or loose components.

Sources

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