BMW Upper Timing Chain Replacement — M50 / M52 / M52TU / M54 / S50 / S52

Replace a worn or stretched upper timing chain with this OE-quality BMW Upper Timing Chain Replacement. The upper timing chain is responsible for keeping the camshafts properly synchronized and works together with the upper timing chain guides and tensioner to maintain accurate valve timing.

Although BMW timing chains are designed for a long service life, decades of use, high mileage, worn guides, and failing tensioners can eventually lead to chain wear or elongation. If you're already performing a VANOS or timing system service, replacing the upper timing chain along with the guides and tensioner is smart preventative maintenance.

Product Details

• OE-quality replacement upper timing chain
• Direct replacement for the original BMW chain
• Maintains proper synchronization between the camshafts
• Works with the upper timing chain tensioner and guide rails
• Recommended during complete timing system repairs
• Ideal for high-mileage engines and preventative maintenance

Replaces BMW Part Numbers

• 11311432177
• 11311730188
• 11311722753

What Does the Upper Timing Chain Do?

The upper timing chain is an important part of the engine's mechanical timing system. It transfers rotation through the upper timing assembly to maintain the correct relationship between the intake and exhaust camshafts.

Proper synchronization is critical to engine performance and VANOS operation. Excessive chain wear or stretch can introduce additional slack into the system, forcing the tensioner to compensate and increasing wear on the plastic timing chain guides.

If wear becomes severe enough, incorrect mechanical timing can result in poor engine operation or potentially serious engine damage.

Common Symptoms of Timing Chain Wear

• Rattling or Slapping Noise — Excessive chain movement can create noticeable noise from the timing case.
• Startup Rattle — A worn chain, guide, or tensioner may be especially noisy immediately after startup.
• Poor Engine Performance — Excessive timing chain wear can affect accurate camshaft timing.
• Timing or VANOS Faults — Incorrect mechanical timing can interfere with proper VANOS operation.
• Excessive Chain Slack — A worn chain may require additional tensioner travel to maintain proper tension.
• Accelerated Guide Wear — A loose or worn chain can place additional stress on the plastic timing chain guide surfaces.

Recommended During VANOS & Timing Service

The chain is only one part of the timing system. The upper timing chain, guide rails, tensioner, sprockets, and VANOS components all work together.

If you're already replacing worn timing chain guides or a failed tensioner, consider replacing the upper chain at the same time—especially on a high-mileage engine. This avoids installing new timing components around an original chain that may already have decades of wear.

Engine Compatibility

Depending on engine and production date, these BMW part numbers cover applications including:

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

BMW Fitment Guide

Important Fitment Note

BMW used different upper timing chain part numbers and configurations depending on engine, production date, and market. The three part numbers listed above cover several generations of BMW inline-six engines.

Verify your original BMW part number, engine code, and production date before ordering, particularly on early M50/M50TU and transitional applications.

Refresh the Entire Timing System

If you're already deep enough into your BMW engine to replace the VANOS, timing chain guides, or upper tensioner, don't overlook the chain itself.

Replacing the upper timing chain along with worn guides and tensioners gives the timing system a more complete refresh and helps ensure the new components aren't being installed around a worn, high-mileage chain.

Replaces BMW Part Numbers: 11311432177, 11311730188, 11311722753