Guide Rail, Cylinder 1-3. Porsche Boxster / Cayman / 996 / 997  ❭  99610505401

Guide rail - Cylinder 1-3.
The timing chain tensioner is designed to maintain correct chain tension in Porsche M96 and M97 engines. This hydraulic tensioner ensures the timing chain remains tight, properly aligned, and stable across all engine speeds, preventing chain slack, noise, and timing deviation.

Fits:
Porsche 986 Boxster 2.7L /  3.2L  2003 - 2004
with Engine codes: M96.23 / M96.24

Porsche 987 Boxster 2.7L / 3.2L / 3.4L 2005 - 2008
with Engine codes M96.25 / M96.26 / M97.20 / M97.21 / M97.22

Porsche 987C 2.7L / 3.4L Cayman 2006 - 2008
with Engine codes  M97.20 / M97.21 / M97.22

Porsche 996 3.6L C2 / C4 / C4S 2002 - 2005
with Engine codes M96.03

Porsche 997.1 3.6L /3.8L  2005 - 2008
with Engine codes M96.05 / M97.01

Diagram Ref No 33.

Built to original Porsche specifications, the tensioner uses controlled oil pressure to absorb chain vibration and compensate for thermal expansion, ensuring precise valve timing and smooth engine operation. 

Over time, the timing chain tensioner can weaken internally, allowing the chain to develop slack and produce rattling noises, especially on start-up. A failing tensioner can cause timing drift, poor running, and accelerated wear of the guides and sprockets. If left unresolved, the chain may even skip a tooth, risking serious internal engine damage. Replacing the tensioner restores stable chain control, accurate timing, and long-term engine protection.

When to replace:
• You hear chain rattle, especially during cold start
• Fault codes or symptoms indicate timing deviation
• Engine runs rough, lacks power, or shows intermittent misfires
• Visible wear or oil leakage around the tensioner housing
• Chain guides have been replaced during an engine service
• Preventatively during M96/M97 engine rebuilds or high-mileage maintenance

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99610505401

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