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Ask Greg Szczygiel Your Own Question
Greg Szczygiel
Greg Szczygiel, UK Car Mechanic
Category: Car
Satisfied Customers: 12
Experience:  Vehicle technician and electrician currently working in reputable independent garage in UK. Fully acredited ATA diagnostic technician.
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Mercedes C280 V6 W204 2007 30000miles Runs prefect but engine

Customer Question

Mercedes C280 V6 W204 2007 30000miles
Runs prefect but engine management light comes on about once per 300 mile the goes off after about four spaced restarts. Just annoying me last year.
OBD2 codes P0015 and P0025 show on my phone checker app." chamshaft position actuator retarded"
I recently had service and oil change to the best recommended oil and filters and it seem to help but it came back. I cant pin it down to a pattern but it seem to occur more when cold but that's not clear.
The engine is perfectly clean no sign of oil or leaks, no smoke or other signs.
The Merc. dealer wants £130 to check it and give me quote repair.
My query is whats the next step?
Can cam sensors fail? can they be checked with a multimeter , are they a first resort?
If it that does not sort it what next ?
Is the Merc dealers check a best starter?
Internet research suggests it could be
Submitted: 3 years ago.
Category: Car
Expert:  Greg Szczygiel replied 3 years ago.
and welcome to Just Answer,my name is ***** ***** I'm looking forward to find the answer to your question.
You can find many independent car specialists garages which can tell you what the problem is than £130.
With the fault codes I must advise to connect your car to more professional diagnostic tool because it may give more specific information about the condition when the fault has existed.
The next step is to book it in the specialist garage or main dealer, this can save you money in the long run.
If the fault codes which you have read with your equipment are truth you can suspect cam position sensor (or wiring) to be faulty as well as variable timing actuator, timing chain issue and oil pressure.
Cam sensor can fail intermittently, most of the times the fault is not present when sensor is tested as it is intermittent.
Cam sensor can be checked with multimeter but only power supply and ground. You will need oscilloscope to check the signal.
Depending on the price of new sensor you can try to gamble and it may work.
If replacement of the sensor will not fix it, it can be the actuator or mechanical fault as I mentioned before.Further checks will have to be done.
All of the above is based on the fact that the fault codes are truth.
I hope this answers all of you questions, I'm happy to assist you further.
Customer: replied 3 years ago.


.Thank you quick reply that supports what I think myself as owner of cars 65 years.

I was hoping that as an expert in the modern computer aided car age and Mercedes, that you could happen tell me if the fault I discribe was common to that car,and the common repair that was done.

The US forums tend to suggest it could be, has there is a hint of a US recall.

Also as the car, starts, ticks over &. runs.prefectly having done only 31000 miles fully seviced should I concern myself that doing nothing is going to lead to breakdown.

Can I summerise your advice to " take it to a dealer diagnostic check" as that the only sure way with this type of fault?

Do you know of any independent national car servicing that do diagnostic checks?

Thanks Harry

Expert:  Greg Szczygiel replied 3 years ago.
I can check if there is a recall applicable to your vehicle but I will need registration number.
If it is common fault than yes it there should be a common fix.
I wouldn't recommend to do nothing about it, if this is the start to more serious problem I strongly advise to have it checked.
Yes taking it to main dealer is sure way to deal with this problem.
Yes I know and I could recommend you independent garages in your local area.
Customer: replied 3 years ago.

thanks again

with a v6 are the two fault codes p0015 and p0025 indecating from two sensors one on each side or could that double fault come from a single sensor?

The case of two sensors having identical faults is unlikely and just a sensor change unlikly to cure the fault.

I bought the car from an independant 18 month ago. The EML came on twice in the first two month and the dealer said it was due to cheap petrol use.I tried the better petrol and it seemed a littlle better while . I was then adviced to do an oil change and make sure that the best recomended oil and filters were used . That again seemed to be a benefit while. The car was seviced & MOT as perfect but this annoying fault came back a week latter

I do little milage and the time between the EML showing is weeks so time goes on.

It seems my first Mercedes after 20 odd trouble free years running Hondas is not a good move or mabe just bad luck with this one.

Out of interest how do the sensors work are they just as the old distributer weights and advance the ignition or do the act on oil pressure and alter the actual valve lifting? If its the latter my engine could have a fault with that item that could prove expensive to repair?

May be that was why someone sold it with when it had only done 25000 mies.

The dealer checked call back thanks

I suppose your answer athough dissapoiting is the only answer to modern car engines. The computer has taken over from experience.



Expert:  Greg Szczygiel replied 3 years ago.
You're welcome,
Camshaft position sensors use hall effect to represent camshaft position, The actuators alter the oil quantity to effectively change the timing (position of camshaft vs position of crankshaft)
To read more about hall effect please visit the link below .
I hope my answers helped you enough to make correct decision.
'My query is whats the next step?
Can cam sensors fail? can they be checked with a multimeter , are they a first resort?
If it that does not sort it what next ?
Is the Merc dealers check a best starter?'
Best of luck