S54 VANOS gear bolts loose

Carlos Technical Support Specialist Ann Arbor, Michigan Posted   Latest   Edited  
Tech Tip
Driveability
2002 BMW M3 3.2L (S54) 6-spd
Rattle
Start Up

S54 VANOS gear bolts are broken or loose. 

A rattling noise can be heard in the valve cover. Broken or loose cam gear to cam bolts may cause the exhaust gear oil pump drive tang to break. If all 6 bolts break on either cam it could cause major engine damage. 

Replace all 24 Vanos gear bolts, 12 of each type. Use lock tight and torque to spec. 

Part number … are often mistaken as the cam hex head bolts … 

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Ray Diagnostician
North York, Ontario
Ray Default
 

Carlos, thank you for the info!

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Ronald Mechanic
Birmingham, Alabama
Ronald Default
 

Thank you.

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Roger Owner/Technician
Chester, Vermont
Roger Default
 

Agreed on the cam bolts. Something else to look at when you are in there might be the Vanos System. Beisan Systems has some great rebuild parts, tools and information on rebuilding the Vanos System on these cars. Another typical problem is the upper timing chain guide tends to break causing a rattle at start-up and at certain RPMs. Not too hard to change when you are in there. Beisan Systems…

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Jason Technician
Ronkonkoma, New York
Jason Default
 

All i not lost if the tangs break, I have used the repair kit from drvanos​.​com with great success. Did not require removing the head like the SI tell you do do. All told the repair took about 3 hours. drvanos​.​com/collections/s5…

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