Aug 272015
 

petrol engine very noisy and rattling. sounds like a diesel. its booked in next week for timing belt, water pump and fan belt change. im not very mechanical but been reading up on the dephaser pulley. if all these were done would this be the best hope of making the engine sound more healthy? thanks

  One Response to “2004 renault megane 2.0l”

  1. I would have to agree if the cause is the dephaser which it sounds like it is.

    The dephaser pulley is all part of the variable valve timing system.Some systems are oil pressure dependent, some are purely electronic, and to be honest I’m not sure which system Renault use.

    The unit alters the valve timing in relation to the crankshaft as the engine speed increases(hence Variable Valve Timing). I’m not sure if these units ever fail after starting to make a noise,but to be honest the damage that would be done if it did would be catastrophic to the engine internals so it’s probably a good idea to have it changed!.

    I suspect that Renault use an oil pressure related system and the dephaser drains out if it’s left for any time, hence why it rattles on initial start up until pressure builds up again. I expect the modified replacement would have a valve built into it to prevent this from happening, but I could be wrong about that.

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