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Problems with the variable valve timing actuator: symptoms, cost and affected models

We have documented 11 faults with the variable valve timing actuator in 11 engines, affecting 65 models of car in our database. The most important by severity and frequency: loosening of the camshaft adjuster bolts (Porsche V8 and V6 (Cayenne and Panamera)), wear of the Valvetronic and the VANOS solenoid valves (BMW N43/N46) and camshaft adjuster oil leak into the wiring (M111).

Documented faults
11
2 of high or critical severity
Engines
11
with at least one fault on this part
Affected models
65
car generations in our database
Garage repair
No data
No reliable published costs

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How it works and why it fails

Variable valve timing (VVT) actuator

The variable valve timing actuator (cam phaser, VVT or VANOS depending on the brand) advances or retards the camshaft according to engine speed to gain power and reduce consumption. It works with oil pressure and solenoid valves, so it is sensitive to the condition of the oil and to leaks into the electrical connectors.

What to do

A rattling noise on start-up, an uneven idle or the engine warning light with camshaft position codes are the usual warnings. Also check for oil in the solenoid valve connector: on some engines it wicks along the wiring all the way to the control unit.

General explanation by MotorFiable. The specific faults of each engine and car, with their sources, are on the linked pages.

Common symptoms

The symptoms that come up most often in the documented faults with the variable valve timing actuator. Open each one to see what other faults cause it.

Problems with the variable valve timing actuator by engine

From most to least important (severity × frequency). Each page details the affected versions and years, symptoms, cost and how to check for it.

  1. 1High severityFrequency: OccasionalPorsche V8 and V6 (Cayenne and Panamera)Loosening of the camshaft adjuster boltsPorsche acknowledges that the fixing bolts of the camshaft adjusters on certain Cayenne S and Turbo and Panamera models built up to September 2011 can fail: noise, vibration, engine warning light and, in rare cases, stalling. There has been a worldwide workshop campaign since 2012.
  2. 2Medium severityFrequency: CommonBMW N43/N46Wear of the Valvetronic and the VANOS solenoid valvesOver the years, the eccentric shaft or the actuator motor of the Valvetronic can wear and cause heavy idle fluctuations; the VANOS solenoid valves also fail over time, with similar symptoms and a loss of power. According to English-language Wikipedia, the 1.6-litre N43B16 does not have Valvetronic.
  3. 3Medium severityFrequency: CommonM111Camshaft adjuster oil leak into the wiringYes: the magnet (solenoid valve) of the M111 camshaft adjuster can lose its seal, and the oil creeps up by capillary action to the connector and the wiring loom. Mercedes-Benz has the same repair cable as for the M271 (part number A2711502733), which is cheap to fit.
  4. 4Medium severityFrequency: CommonM271Oil leaking from the camshaft adjuster solenoids into the wiringYes: the camshaft adjuster solenoids (magnets) of the M271 can lose their seal, and the oil wicks up to the connector and the wiring loom, and can even reach the control unit. Mercedes-Benz has a specific repair cable (reference A2711502733) that is cheap to fit.
  5. 5Medium severityFrequency: CommonM270/M274Oil leaking from the camshaft adjuster into the electrical connector (M274)Yes: on the M274, the camshaft adjuster solenoids can lose their seal over the years and let oil wick up to the connector and the wiring harness, potentially reaching the ECU. It is fixed relatively cheaply with a specific repair cable.
  6. 6Critical severityFrequency: Rare1.2 and 1.4 TSICamshaft adjuster and belt failure (EA211, 2013-2015)On some 1.2 TSI EA211 engines built mainly in 2014, the camshaft adjuster bolts came loose, jammed the wheel and snapped the belt, causing serious engine failure. Volkswagen recalled units from late 2013 to 2015 (action 15H2).
  7. 7Medium severityFrequency: Occasional1.3 TCeTiming phaser faultA fault in the camshaft phaser can turn on the injection warning light and sometimes cause a loss of power in the 1.3 TCe/DIG-T. Renault-Nissan corrected it at the factory in February 2021; the repair involves checking the solenoid valves and, if necessary, replacing oil control valves.
  8. 8Medium severityFrequency: Occasional1.25/1.4/1.6 Ti-VCTTi-VCT actuator or solenoid valve failure on the early unitsYes, mainly on the oldest units of the Ford Focus II and C-Max I: the actuator or solenoid valve that controls the Ti-VCT variable timing can seize or leak oil, causing timing noise and an engine warning light. Ford revised the design and the fault does not appear on the Focus III, the C-Max II or the B-Max.
  9. 9Medium severityFrequency: Occasional2.0 16v F4R and F4RTFaulty camshaft variable valve timing pulleyOn the F4R 2.0 16v the variable valve timing pulley can degrade and cause a metallic, diesel-like rattle at idle or when warm. The sources put it at around 120,000 km on the Mégane II; replacement is expensive if done together with the timing belt kit.
  10. 10Medium severityFrequency: Occasional1.4 and 1.6 16vVariable valve timing unit failure (dephaser pulley)K4M versions with a variable valve timing unit can suffer a failure of the unit's pulley (déphaseur): unstable idle, hard cold starting and a metallic knock on start-up. It is a minority of the documented cases, but it recurs across several different generations.
  11. 11Low severityFrequency: RareMIVEC gasolinaStuck MIVEC variator and hard cold starting on the 1.6 (4A92)On the Lancer 1.6 MIVEC (4A92) customers complained of long cold starts: according to Auto.cz, the MIVEC variator could stick in an intermediate position and let exhaust gases into the cylinders. It is the known fault that this used-car test points to.

Engines with faults with the variable valve timing actuator

Variable valve timing actuator: compare prices in shops

Search for the part using the make, model and engine of your car: in the shop, the registration plate or VIN filters the parts that fit.

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Problems with the variable valve timing actuator by make

Problems with the variable valve timing actuator in your car

7 cars have several documented faults with the variable valve timing actuator. Choose yours to see only the ones that affect them, by engine and by year.

Mercedes-Benz 2
Renault 5

OBD fault codes with the variable valve timing actuator

The codes the ECU usually stores when this part fails: what they mean, causes and what to check.

Frequently asked questions

Which engines have the most faults with the variable valve timing actuator?

By severity and frequency, the Porsche V8 and V6 (Cayenne and Panamera) (loosening of the camshaft adjuster bolts, high severity), the BMW N43/N46 (wear of the Valvetronic and the VANOS solenoid valves, medium severity), the M111 (camshaft adjuster oil leak into the wiring, medium severity), the M271 (oil leaking from the camshaft adjuster solenoids into the wiring, medium severity), the M270/M274 (oil leaking from the camshaft adjuster into the electrical connector (M274), medium severity) and the 1.2 and 1.4 TSI (camshaft adjuster and belt failure (EA211, 2013-2015), critical severity). In total we have documented 11 engines with faults with the variable valve timing actuator.

What symptoms does a fault with the variable valve timing actuator cause?

The most frequently cited in the documented faults: engine fault warning light (check engine), visible oil leak, abnormal vibrations or unstable idle, hard starting or engine will not start, metallic timing noise on start-up and noise when starting the car (squeal, knock or clicking).