Why are my intake camshaft bolts not working?
Certain late model BMWs can experience a problem with the camshaft sprocket retention bolts failing. This is a design defect, and well know in professional BMW service circles. You can see on the photo below, that VANOS (variable valve timing system) to intake camshaft bolts have broken and backed out, 3 of the 4 bolts are damaged and loose.
What happens if the camshaft bolts break on a BMW?
BMW said “in very rare cases the bolts holding the variable camshaft timing (Vanos) unit housing may become loose or, in extreme cases, break.” In such cases, the driver would be alerted by a check-engine warning light.
What are the symptoms of a BMW camshaft problem?
Or a bolt backs out and falls into the timing change, Either way, a very bad day. Signs and Symptoms of this problem include VANOS fault codes, rough idle, engine noise, knocking or clicking sound, maybe a rumbling noise. Then, if not corrected, the KABOOM. An expensive “KABOOM”.
Certain late model BMWs can experience a problem with the camshaft sprocket retention bolts failing. This is a design defect, and well know in professional BMW service circles. You can see on the photo below, that VANOS (variable valve timing system) to intake camshaft bolts have broken and backed out, 3 of the 4 bolts are damaged and loose.
How to remove camshaft sprocket when replacing timing belt?
How to remove camshaft sprocket when replacing timing belt & water pump or camshaft oil seals. – YouTube
What kind of bolts are in BMW camshafts?
You can see on the photo below, that VANOS (variable valve timing system) to intake camshaft bolts have broken and backed out, 3 of the 4 bolts are damaged and loose. BMW said “in very rare cases the bolts holding the variable camshaft timing (Vanos) unit housing may become loose or, in extreme cases, break.”
Or a bolt backs out and falls into the timing change, Either way, a very bad day. Signs and Symptoms of this problem include VANOS fault codes, rough idle, engine noise, knocking or clicking sound, maybe a rumbling noise. Then, if not corrected, the KABOOM. An expensive “KABOOM”.
How big of a torque wrench do I need to back up a cam Hex?
Check to see that the sprockets are fully seated against the cams before torquing the bolt tight. Always use a 24 m.m. or 15/16” wrench on the cam hex to back up your torque wrench (never use the chain for resistance)! Torque the cam sprocket bolts to 94 to 115 ft-lb.
BMW said “in very rare cases the bolts holding the variable camshaft timing (Vanos) unit housing may become loose or, in extreme cases, break.” In such cases, the driver would be alerted by a check-engine warning light.
What should torque be on a cam sprocket?
Torque the cam sprocket bolts to 94 to 115 ft-lb. Check that your original chain marks still align with the marks on the sprockets and the lobes still point away from the center of the engine. Remove the tensioner locking wire you in- stalled. Inspect your work carefully.