Megane 2.0 16v problem

[georgiminkov]

Hey guys,

I drive a 2.0 16v phase 1 Megane and my issue started after I got my dephaser changed at Renault's. When I put my foot down at 40%/50% throttle and up, there is a hissing/exhaust leak type of sound coming from under the car or the engine bay area. It disappears when you let off the throttle. The car definitely loses power when that happens and I got a misfire on cylinder 4 a few times when I pushed it. It only comes on when the car is moving.

I went to an exhaust garage and they said there are no exhaust leaks. I found a split in half PCV valve hose which I replaced and ordered a new PCV valve. I plugged in the old one in the meantime, but it doesn't seem to be running any differently. I also swapped the coils from cylinder 1 and 4, so I can see if the code for the misfire is different if I get one again. I've also cleaned the throttle body. If you accelerate gradually, the car seems to be running ok.

Any advice/help is welcomed, since I've been banging my head trying to figure this out. Are there any more vacuum hoses I can check? I've been looking through the repair PDFs and I couldn't find anything.

Thanks in advance!

[ledispositif]

Hello georgiminkov, I am experiencing an identical problem with the same engine so was wondering if you have had any luck sorting it out?

The noise I get is very similar - a strange hissing/exhaust/tapping noise similar to a tiny turbo spooling up, but only when accelerating hard or under load eg. up a hill. If I drive the car gently it doesn't do it at all and the car runs very well. If I keep pushing the car hard it will make the noise and then misfire or skip and lose power until I release the accelerator a little.

I figured it must be a vacuum or inlet problem as it is causing a misfire - sucking air in to make it run lean? Just a guess though. I couldn't find any exhaust leaks either.

I have changed the inlet manifold gaskets - the rubber ones between plastic and aluminum manifold inlets and the throttle body to inlet manifold gasket. All were pretty hard and rough looking.

The area behind the join on cylinder number one had a small oil leak around it and that gasket was a little worse than the others. There was also a fair amount of oil in the inlet manifold when I took it off, maybe 100mls or so. There were no cracks or tears in the crankcase breather hose.

Since changing the gaskets there has been a slight improvement in the noise ie. it doesn't do it as much and it seems to need to be pushed a little harder to make it misfire and skip. But it is still there.

Did you have any luck with the pcv/oil vapor valve? That was going to be my next step. I noticed when I removed the manifold that there is also a small plastic box inline with the hose between the crankcase and the vapor valve, as yet I haven't been able to work out what this is, as it isn't shown in any of my manuals...

Any help or suggestions you can offer would be much appreciated. Hopefully you have had more success than me sorting this out.