Camshaft Chain and Tensioner Replacement (16V)

Overview

This procedure replaces the camshaft chain and tensioner on the Porsche 944 S2 with its 3.0L 16-valve engine. The exhaust camshaft is driven by the timing belt, while a chain connects it to the intake camshaft. An oil-fed tensioner maintains chain tension, but wear—often around 100,000 to 130,000 miles (161,000 to 209,000 km)—can lead to failures in the oil supply tube or tensioner components, risking damage to cams and valves. This guide is tailored for DIY enthusiasts working on the S2’s 3.0L engine.

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

Tools Required

• 10mm (3/8 inch) wrench
• 13mm (1/2 inch) wrench or socket
• 17mm (11/16 inch) socket
• 8mm spline drive bit (12-point)
• 10mm spline drive bit (12-point)
• Pin spanner (for cam pulley)
• Socket set (various sizes)
• Torque wrench
• Scribe or fine marking tool
• 6-inch (152mm) steel rule
• Rags (for blocking oil galleries)
• Thin metal strip and nails (for tensioner compression)

Parts Required

• Timing Chain – 944 105 501 01
• Tensioner – 944 105 049 01
• Oil Supply Tube (J-Tube) – 944 105 167 03
• Seal Rings (for J-Tube, 4 required) – 900 123 115 30 or N 013 807 09
• Cam Housing Gasket – 944 105 165 03
• Top Tensioner Pad (optional, if available separately) – 928 105 509 01
• Bottom Tensioner Pad (optional, if available separately) – 928 105 347 01

Required Additional Procedures

Steps in these procedures are required to complete this process:

• Timing Belt Removal
• Balance Shaft Belt Removal

Step-by-Step Procedure

Step 1: Prepare the Engine

1. Disconnect the negative battery lead to prevent electrical issues.
2. Remove the cam cover and inspect it for chain rub marks. Check the cylinder head too.
3. Stuff clean rags into the oil drain galleries near the exhaust valves to catch any dropped parts.

Step 2: Inspect and Remove Accessories

4. Inspect the chain tensioner and oil feed pipe for wear or cracks. Replace if damaged.
5. Remove the air filter housing and inlet pipe up to the air flow meter.
6. Take off the power steering pump and alternator belts.
7. Disconnect the Hall sensor wire at the rear of the exhaust cam sprocket and move it aside.
8. Use a 10mm (3/8 inch) wrench to remove the bolts from the black plastic covers at the engine front, then remove the upper and lower covers.
9. Remove the distributor cap and plug wires (3 screws).
10. Take off the metal cover over the exhaust cam sprocket.
11. Remove the ignition rotor from the cam sprocket (3 screws). Optional: Reinstall the screws to lock the pulley to the “propeller” piece behind it to preserve cam timing.
12. Remove the fan assembly from the radiator for better access.

Step 3: Set Engine to Top Dead Center (TDC)

13. Turn the engine until the cam pulley mark aligns with the line on the metal cover behind it. Verify the crankshaft is at TDC by checking the flywheel mark (labeled “OT”) through the clutch bell housing square hole, aligning with the pointer.
14. Ensure the balance shaft sprocket notches align with their marks: upper at 12 o’clock, lower at 7 o’clock on the plastic cover.

Step 4: Remove Belts

15. Follow this link to ensure this step – Timing Belt Removal – of the process is followed accurately.
16. Follow this link to ensure this step – Balance Shaft Belt Removal – of the process is followed accurately.
17. Do not turn the crankshaft after belt removal to avoid valve damage.

Step 5: Mark and Remove Cam Pulley

18. Scribe precise alignment marks on the exhaust cam, pulley, and adjacent bridge piece. Use a 6-inch (152mm) steel rule for accuracy.
19. Hold the pulley with a pin spanner and remove the pulley bolt with a 10mm spline drive bit (torque to crack loose: 102 Nm (75 ft-lbs)). Remove the washer and pulley.
20. Remove the rear metal pulley cover (3 bolts) and the front bridge piece (4 bolts).
21. Take off the exhaust cam end seal and inlet cam end bung.

Step 6: Replace Chain and Tensioner

22. Compare the new chain (944 105 501 01) to the old one. Align the copper links with the triangular pointers on each cam sprocket.
23. Remove the oil supply tube (944 105 167 03) by unscrewing both banjo bolts and removing the sealing washers (900 123 115 30 or N 013 807 09).
24. Compress the tensioner’s upper rubbing block with a metal strip and nails, then remove the tensioner (944 105 049 01) by undoing its two bolts.
25. Gradually loosen the cam retaining cap bolts (8mm spline drive bit) a quarter turn at a time. Note cap numbers (1-8) and orientation.
26. Lift out both cams with the old chain, avoiding damage to bearings or followers.
27. Install the new chain, ensuring copper links align with the sprocket teeth at the pointers.

Step 7: Reassemble Cams and Pulley

28. Lube cam bearings and refit the cams with the new chain, aligning pointers and copper links.
29. Reinstall cam caps in their original positions and orientations. Tighten bolts gradually to 20 Nm (15 ft-lbs).
30. Refit the exhaust cam seal, inlet cam bung, and front bridge piece (use a thin smear of sealant).
31. Reinstall the rear metal pulley cover and slide the pulley onto the cam, aligning all scribed marks.
32. Reattach the “propeller” and shield, then torque the pulley bolt to 65-70 Nm (48-52 ft-lbs) with Loctite, using a pin spanner to hold it.

Step 8: Final Reassembly

33. Reverse the removal steps: reinstall belts, covers, distributor cap, wires, fan, belts, air filter housing, and battery lead.
34. Remove rags from the oil galleries.
35. Turn the engine by hand (plugs removed) for several revolutions to check for resistance.

Post Procedure Checklist

• Verify all scribed marks align at TDC.
• Check belt tension and alignment.
• Inspect for oil leaks around the J-tube and tensioner.
• Ensure no unusual noises when turning the engine by hand.

Sources

• Clark’s Garage
• Pelican Parts
• Porsche 944 Workshop Manual, Volume 1
• Youtube