Cars:
- 4 cyl. 6 cyl. V8 & V12
- 318 and 318ti E46 N42 Facelift
- 118 and 120i
- 320i E90 N46
- 5series E60
Symptoms of failure:
- EML light on – yellow light and car warns to drive moderately and have engine checked
- Car loses power – in limp mode
- Heavy on fuel
- Symptoms occur intermittently until car cuts off or refuses to start
- “valvetronic servo motor” faults
- “eccentric shaft sensor” faults – in more extreme conditions and usually cancels out once the VVT motor is fitted
What it looks like:
How it works:
The little electric VVT motor sits at the top of this intricate system and is situated above the cylinder head
This motor turns the eccentric shaft, which pushes the intermediate rocker arms and in turn pushes the valve to open deeper to allow for more power.
Because the lift of each valve per cylinder is controlled or varied continuously according to the revs, the engine will perform at optimum efficiency and hence balance will occur with power, fueling and engine breathing. Note this motor has replaced the conventional throttle butterfly but the latter is still fitted as a back up or safety.
“BMW state a saving on fuel of up to 10%, cold start behaviour, reduces emissions and smoother more responsive power.” It however does not advance top end power.
The VVT Motor and the vanos units usually fail because of sludge. See article on sludge.
Replacement:
1 Day job
VVT motor + Tappet Cover Gasket + Tappet Cover Flange + Software and Labour
We do not recommend fitting used VVT Motors as it is bound to fail and there is no guarantee.
Note:
In the 2nd diagram you will see some of the parts that make up the complete Valve Timing system.
- Eccentric shaft sensor (similar symptoms when it fails – will be explained in next article)
- VVT Sensor
- VVT control unit ( not in pic – seldom problematic)
Vanos Unit/Gears – Inlet and Outlet Adjustment Units (not in pic – if the car has single or double vanos variable timing – will be explained in another article)
There are 18 Comments
I just got this replaced on my 118 which has 68000kms on the clock, thank goodness its still under motorplan. What causes the VVT to fail?
It fails because of age (wear and tear) and sometimes because of sludge build up.
Good day, how do I obtain a quote to replace the motor and the sensor ?
Hi there, Can the failure of “eccentric shaft sensor” result in failure of a newly replaced VVM to the extent that you need a new
These parts are available at BMW
If the eccentric shaft sensor has failed it will throw the same fault but it does not mean you will need a new VVT Motor. Car must be booked in for me to diagnose accurately.
Hi Tune Tech:
How much about does this job cost? Thanks!
Hi Tune-Tech! thanks for this informative article! my car ahs all the symptoms listed above, it is with the dealership currently as it is still under m/plan. hoping to have the car back this weekend cause i have a wedding which the car needs to be present for. Once again, thanks for your brilliant articles and service!
Ash (BMWFanatics Member)
VVT motor Quote +/- R5998.00incl.VAT
what happens if u keep on driving a car with a vvt motor 4 a long time after the diagnosis
Hi, with my 2005 320i the yellow light came on, they told me it can be the VVT motor that will cost me R2 829 or the sensor for R3 700 so if my car doesn’t lose power at this point and I don’t want to buy both which one will be the problem, the guy told me it’s 9 out of 10 the motor.
Needs to be booked in.
Most likely VVT motor
hi, i have 320i (e90). for the last two months it has got oil leaks on engine and have smoke from tail pipe. and sometime it remians very weak, speed can’t go beyond 60km/h
Hi i got probable causes
1 open or short circuit condition
2 poor electrical conection
Vvt motor
Check the vvt for mechanical stiction and seizure
P 1030
i get 2731 code. camshaft control inlet
Hi, I have a 320i and at 130 000 k`s have just been quoted a relacement of a vvt motor.
About 2 months ago i also had the valves replaced due to oil leaks, which cost me around R6500.00 My concern is that I`ve always been a very big fan of BMW’s and this is honestly the first bmw that I`ve had, that`s had so many issues. I’m starting to wonder if the issues I`’ve had is just normal wear and tear or whether bmw is no longer made to last. I bought the car brand new, its a 2006 model. I love the car, its economical, but becoming expensive to maintain.
Help, I’ve had timing chain, guides & tensioner replaced as BMW dealer said that’s why I had ticking noise. Nouse still there only after about 1 minute start up & more so at between 1800-2000 revs. Took me getting stethoscope to isolate location of noise – at stepper motor. Had another garage look under rocker cover & they say timing gear worn – only 35,000 miles on clock 7 years old 316ti compact. Drives just fine no other issues or fault codes etc. what do I do they want £1500 to replace timing gear & can’t guarantee will fix!! Help!!
2002 318i has an EML light and wont start, engine turns a bit as if battery has low power