Diaphragm on air intake

[Budz]

Hope someone may be able to help me , I have a strange noise from engine and a Renault technician said it was the diaphragm , first of all has anyone else had to replace this ?
What does it do ?
And is it easy to replace and where can I get one cheap
thanks

 

[Chris]

Not heard of that one before.

Have you got a video of the noise? Is the noise constant/worsen when you apply throttle?

 

[Budz]

It's mainly from a cold start or even if the engine is slightly warm , it's Intermittent whine like a fuel pump sort of sound , I have a vid but don't know how to upload it could email it if u think you can help cheers

 

[Chris]

Upload it to youtube or vimeo, or photo bucket. I'm no expert by any means, but these cars make all sorts of sounds that could be various different things.

 

[chris mcm]

PCV valve? Mine needs replaced too, sounds like really weak high pitched trumpet haha. Only happens when you press the accelerator, you can't hear it when on the road.

 

[AshK]

Pav valve? Mine needs replaced too, sounds like really weak high pitched trumpet haha. Only happens when you press the accelerator, you can't hear it when on the road.

Mine makes this exact noise, excuse my ignorance but, the hell is a pav valve ha?

 

[chris mcm]

Sorry I've fixed my autocorrect mishap, it's a PCV valve. £40 from Renault last time I checked, it's nothing to worry about, just annoying. Il get around to it at some stage.

 

[petercronin]

Sorry I've fixed my autocorrect mishap, it's a PCV valve. £40 from Renault last time I checked, it's nothing to worry about, just annoying. Il get around to it at some stage.

PCV - Positive Crank-case Ventilation valve. The air that bleeds past the piston rings into the crank case is vented back into the inlet to avoid over pressure. I think on older cars it was simply dumped to atmosphere but to be all Eco-friendly it's now put back into the engine to be burnt.

My last Clio did this too. The valves can be cleaned out with carb cleaner if they're not too bad. I was under the impression that if they do fail they can cause problems due to over-pressure in the crank case. Really easy job to clean or replace them.

 

[chris mcm]

Wonder if there are any guides on here for changing it. My mechanic had my out and cleaned it with carb clearner and that didn't work unfortunately

 

[petercronin]

Wonder if there are any guides on here for changing it. My mechanic had my out and cleaned it with carb clearner and that didn't work unfortunately

It's pretty easy to do (from memory) the pipe that goes down to the back of the crank case just pulls off the valve and the valve is held onto the air intake by a clip that's part of the valve itself (just needs bent out of the way slightly) and it should just pull out of the intake.