BMW S50B32 Timing Chain Tensioner / Upgrade — 11311405081

Maintain proper timing chain tension and reduce unwanted timing chain noise with this BMW Timing Chain Tensioner, originally designed for the European S50B32 engine.

The timing chain tensioner maintains pressure against the timing chain guide rail, keeping the chain properly tensioned as the engine operates. As a tensioner wears, it can lose its ability to maintain adequate pressure, allowing excessive chain slack that can result in startup rattle, timing case noise, accelerated guide wear, and potentially serious timing problems.

BMW part number 11311405081 features an updated design and is also commonly used by BMW enthusiasts as a timing chain tensioner upgrade on several earlier BMW engines.

Product Details

• Replacement engine timing chain tensioner
• Originally designed for the S50B32
• Updated tensioner design
• Maintains proper pressure against the timing chain guide
• Helps reduce excessive timing chain slack
• Common upgrade for several older BMW engine families
• Can replace the early mechanical tensioner on applicable M50 engines
• BMW Part Number: 11311405081

What Does the Timing Chain Tensioner Do?

The tensioner applies pressure to the timing chain guide system to maintain proper chain tension throughout engine operation.

Too much slack allows the chain to move excessively between the crankshaft and camshaft sprockets. This can create noise, accelerate wear on the chain and guides, and in severe cases allow the engine to jump timing.

Because timing chain tensioners can depend on the engine's lubrication system for proper operation, engine oil level, oil pressure, and oil flow should also be checked when diagnosing timing chain problems.

Common Symptoms of a Failing Timing Chain Tensioner

Symptoms can include:

• Rattle on Startup — Chain slap or rattling immediately after starting the engine can indicate insufficient tension.
• Rattling or Clanking From the Timing Case — Excessive chain movement can create noticeable noise from the front of the engine.
• Timing-Related Fault Codes — On applicable engine management systems, excessive timing deviation may trigger camshaft/crankshaft correlation faults.
• Excessive Timing Chain Slack — A worn tensioner may no longer maintain adequate pressure against the guide.
• Accelerated Timing Guide Wear — Excessive chain movement can place additional stress on timing system components.
• Potential Engine Damage — If an interference engine jumps timing far enough, piston-to-valve contact and major engine damage can occur.

Updated S50B32 Design

This tensioner was originally designed for the European-market S50B32, but its updated design has made it a popular upgrade for several earlier BMW timing systems.

Enthusiasts commonly use this tensioner as an alternative to the original tensioners found on:

• S50B32
• S38B36
• S38B38
• S14
• Early M50
• Early M50TU

The updated design can provide improved operation and service life compared with some of the older tensioner designs.

Early M50 / M50TU Upgrade

This tensioner can also be used on applicable M50 and M50TU engines produced before approximately 09/1994 as an upgrade over the original mechanical-style timing chain tensioner.

This makes it a popular preventative-maintenance upgrade for early E34 and E36 M50-powered BMWs, particularly when the timing system is already being serviced.

Primary Factory Fitment

BMW 11311405081 was originally intended for the S50B32 engine.

*European and other non-North-American market applications. Production dates and market availability vary.

Common Upgrade Applications

This tensioner is also commonly used as an upgrade or retrofit on applicable:

*For applicable M50/M50TU engines produced before approximately 09/1994. Verify your engine's production date and existing tensioner configuration before ordering.

Important Retrofit Note

The S14, S38, and early M50/M50TU applications are enthusiast retrofit/upgrade applications, not necessarily the original factory application for BMW part number 11311405081.

We recommend verifying compatibility with your specific engine and timing system before using this tensioner as a retrofit.

Hearing a Timing Chain Rattle?

A worn tensioner is one possible source of timing chain noise, but it isn't the only one.

If you're hearing a loud rattle from the timing case, replacing an old tensioner is a good place to start. If the noise remains afterward, the timing chain, guide rails, sprockets, and other timing system components should be inspected.

Don't assume a new tensioner will compensate for worn or damaged timing components.

A Proven Upgrade for Older BMW Timing Systems

Whether you're replacing the original tensioner on an S50B32 or upgrading the older design on an S14, S38, or early M50 application, BMW 11311405081 provides an updated solution for maintaining proper timing chain tension.

It's a relatively small component with an extremely important job: keeping your timing chain where it belongs.