Blog 6: BMW MINI B38 B48 Vanos Cam Gear Drivetrain Fault
As the BMW MINI B38 B48 engines get into the higher miles we are starting to see an increasing volume come through the workshop with the same faults present. Initially the car may behave normally but display a drivetrain error depending on the extent of the failure and if the debris has travelled into the vanos gears. It is vital to get this repaired before further engine damage occurs.
We have seen this failure occur at less than 20k miles!
What Does a Vanos Gear Do?
The vanos gears advance or retard camshaft timing hydraulically, using engine oil pressure, controlled by vanos solenoids. The vanos gears are vital to an engines performance, fuel efficiency and driveability.
The B38 B48 uses double vanos, meaning there are two vanos gears, one for the intake and one for the exhaust. Each gear is mounted on the camshaft, behind the timing chain.
Warning Signs of Vanos Failure
Engine rattle.
Rough idle.
Sluggish power delivery.
Reduced fuel economy.
Check Engine Light.
Typical fault codes
Camshaft timing over-advanced / over-retarded.
Camshaft–crankshaft correlation errors.
VANOS mechanical stop/jamming faults.
The malfunction warning is illuminated. One or more of the following faults are stored in the
DME:
130104 Variable camshaft timing control, intake: Control fault, camshaft jamming
130108 Variable camshaft timing control, intake: Control fault, position not reached
130304 Variable camshaft timing control, exhaust: Control fault, camshaft jamming
130308 Variable camshaft timing control, exhaust: Control fault, position not reached
130E11 Intake camshaft sensor, plausibility: Signal implausible
130E20 Intake camshaft: Angle offset with respect to the crankshaft lies outside tolerance range
130F11 Exhaust camshaft sensor, plausibility: Signal implausible
130F20 Exhaust camshaft: Angle offset with respect to the crankshaft lies outside tolerance range
131401 Variable camshaft timing control, exhaust, cold start: Cannot be controlled
131501 Variable camshaft timing control, intake, cold start: Cannot be controlled
131808 Variable camshaft timing control, exhaust, cold start: Position not reached
131908 Variable camshaft timing control, intake, cold start: Position not reached
Common Failure of Vanos System
The B38/B48 VANOS gear issues often stem from a specific failure where the internal filter screen on the exhaust side's VANOS sprocket bolt breaks, sending debris into the mechanism, causing it to jam, triggering fault codes, and leading to power loss, rough idling, and poor performance.
The above photos show the difference between the new central valve bolt and the original where the mesh screen has failed with debris causing internal damage to the vanos gears. This debris is typically the cause of resulting damage to the cam adjusters and camshafts.
BMW are aware of this common fault - it is explained in their service information bulletin SI M11 02 15.
BMW have issued revised part numbers for many of the above components.
Vanos System Repair
The typical repair for this issue includes replacing both vanos cam gears, both central valve bolts and associated gaskets - some vehicles may also require camshaft replacement and DME ilevel update. This procedure requires various special tools and it is vital that original parts are used here, there are many cheaper parts available that simply do not work or fail prematurely.
The vehicle shown here required camshaft replacement due to the camshaft position pickup being shifted, compared to the acceptable position shown on the official BMW repair document. The new revised part can be seen on the right hand side image compared to the previous design. Typically it is required to replace both camshafts and update the ECU software at this point.
Our experienced technicians follow BMW’s exact procedures, ensuring your engine is repaired perfectly and runs like new.
Whether you drive a 320d or M3, we’ve got the expertise and tools to get the job done right.
Catching problems early can save you thousands in repair bills and keep your BMW performing as it should.
📍 Book your vehicle in today with BM Performance — your trusted BMW MINI specialist.
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