mercedes c350

[ukbertie]

I have a merc c class 350 avantgard i had a warning light come on and i took it to the garage and they told me it was "Intake and exhaust camshaft position sensors on right engine bank" now i know nothing about cars so could anybody please explain what this meens
i think the garage are trying to confuse me just to up the price and if it is what they say is it likely to be very expensive ?

any imput would be appreciated

 

[ukbertie]

forgot to say its on a 55 plate

 

[iwaters]

I'll try to explain in laymans terms as best I can. You have a 2.5 V6, this means that the engine is shapped like a V and has two cylinder heads or banks, so when refering to the right bank they mean the side of the engine on the drivers side.

Now modern engines have an array of sensors to tell the engine computer where certain components are in their rotation. This enables to the computer to change when certain events occur. They are also used to detect when an problem may have occured with the engine. The camshafts are rotated by the engine and the open the valves on the various cylinders in the engine letting in air and petrol and letting out exhaust gasses. There is one camshaft for the air/petrol mixtrure and one for exhaust gas. Your engine also has something called Variable Valve Timing which means the engine computer can change when those valves open. The sensors the garage are talking about are used to keep track of what the camshafts are doing.

There could be any number of reasons for the fault codes the garage have found. It could be a fault with the sensors or it could be a mechanical problem with the belt that drives the various enigne components.

What have the garage suggested they will do to fix it? If you are not happy with the garage's explanantion then take it elsewhere for a second opinion.

I hope that helps, if you want anything else explaining let me know.

 

[ukbertie]

Many thanks for your reply
she is in fact a 3.5 but i expect its the same , the garage have replaced the sensor and it was fine for a cpl of days but now the light has come back on , the car runs fine with no loss of power or juddering shes running as smooth as she allways have , the garage have advised a complete strip down of the right bank but they would as they charge £60 hr and they said it would be 16 hrs work ouch !!!!!!!!!plus they would replace all nesseary parts so looking at well over a grand and they wont guarantee that will fix it ,
my point being if the car is running fine surely the exchaust and mixtures must be fine or she would be missing or poping or at least a power loss but like i say shes running fine

 

[Stivino]

If they won't guarantee that it will be fixed, it sounds like they are guessing as to what is actually wrong with it. i.e. they don't know.
And as it seems they didn't get to the bottom of it the first time, it sounds like you might be throwing good money after bad.

 

[iwaters]

Stivino is right, they don't know what they are doing. I have found this more and more with a lot of garages, rather than having experinced mechanics, they have a lot of fitters who plug their diagnostics in, it tells them there is an error with sensor X so they just change it and hope it goes away.

Find a Mercedes specialist and take it there.

 

[Mickymoody]

It sounds like the timing belt/chain has jumped a tooth, has that been changed recently, or needs to be changed? ie immenent failure/bad work at the garage?

 

[Mursal]

May be corrosion on the wiring plug connecting the sensors on that bank and the Electronic Control Unit, the ECU. Get another garage to check the wiring/connections before stripping the engine, especially if its running fine.