BMW Upper Timing Chain Tensioner — 11311738700

Keep the upper timing chain properly tensioned with this replacement BMW Upper Timing Chain Tensioner. BMW part number 11311738700 is used on a wide range of BMW inline-six engines and is specifically responsible for maintaining tension on the upper timing chain between the camshafts.

The upper timing chain plays an important role in keeping the camshafts synchronized. As the tensioner wears, excessive slack can develop in the chain, potentially causing rattling or clanking noises, inconsistent camshaft timing, timing-related fault codes, and accelerated wear of the timing chain and guide components.

A worn or damaged upper tensioner should be replaced promptly, especially when performing a VANOS rebuild or timing system service.

Product Details

• Replacement Upper Timing Chain Tensioner
• BMW Part Number: 11311738700
• Maintains tension on the timing chain between the camshafts
• Helps prevent excessive timing chain slack
• Helps maintain proper camshaft synchronization
• Recommended during VANOS and timing system repairs
• Fits a wide range of M50, M50TU, M52, M52TU, M54, S50 US and S52 applications

What Does the Upper Timing Chain Tensioner Do?

Unlike the primary timing chain tensioner, this tensioner is used on the upper timing chain between the intake and exhaust camshafts. Its job is to preload the chain and maintain the correct amount of tension as the engine operates.

Excessive slack can allow the chain to move or slap against surrounding components. In severe cases, a timing chain that is not properly controlled can contribute to incorrect camshaft timing and potentially serious engine damage.

Because this component is located within the same area being serviced during many VANOS repairs, it's a good item to inspect and replace while everything is already apart.

Common Symptoms of a Failing Upper Timing Chain Tensioner

• Rattling or Clanking Noise — A worn tensioner can allow the upper chain to move excessively, creating rattling, ticking, or clanking noises.
• Noise on Startup — Chain slap may be especially noticeable immediately after starting the engine.
• Check Engine Light — Improper chain tension can contribute to timing discrepancies and related camshaft/crankshaft fault codes.
• Excessive Timing Chain Slack — A worn tensioner may no longer maintain adequate pressure against the chain.
• Accelerated Guide & Chain Wear — Excessive movement can increase wear on other timing system components.
• Potential Engine Damage — Severe timing problems can result in the valves contacting the pistons on interference engines.

BMW Fitment Guide

Engine Compatibility

M50 • M50TU • M52 • M52TU • M54 • S50 US • S52

Recommended During VANOS Service

If you're already removing the VANOS unit or servicing the upper timing system, this is an ideal time to inspect the upper timing chain, tensioner, guide rails, and related components. Replacing an aging tensioner while the engine is already apart can help prevent having to revisit the same area later.

BMW Part Number: 11311738700