Serpentine belt caught around parts.

Serpentine belt on BMW gets caught in engine

In Diagnostics by Steves Auto Repair and Tire

The driver of a 2009 BMW 535xi had an unexpected experience recently: his car stopped running in the middle of the road.

The culprit? A leaking oil filter housing that caused the serpentine belt to get caught in the engine.

Oil Filter Housing.

Oil Filter Housing

How the serpentine belt became caught

Because of the leak, the serpentine belt — which surrounds parts of the engine — became soaked with oil. It slipped off the pulleys, wrapped around the components, and began to fray.

After getting caught around the crankshaft pulley, the belt started working its way through the crankshaft seal into the timing cover.

Parts of the belt wrapped around the timing chain, throwing the car’s timing off. It was also caught around the oil pan, which clogged up the oil pickup tube and prevented oil from entering the engine. 

Oil pickup tube.

Oil pickup tube

Timing chain replacement

When the customer’s car stopped running, he cranked the car and a crunching metal sound could be heard in the front timing cover. We knew that the timing chain needed to be replaced.

After removing the old timing chain and timing chain unit, our technician cleaned out material from the serpentine belt that had gotten into the timing cover.

New chains, a new tensioner and new bolts for the camshaft, sprockets and crankshaft were then installed.

New timing belt.

New timing belt

Steve’s Auto Repair & Tire is an authorized Goodyear tire dealer located in Woodbridge, Virginia. Automotive repair services are performed on all makes and models, including BMW and Mercedes. Services include oil changes, brakes, alignments, inspections, and computer engine diagnostics.