Megane idle problem


1000+ Posts
If you can think of it, ive changed and swapped with a few expections.

I think im going back to basics - it still feels like a vacuum leak. Now I know its not the upper plastic manifold or any of the sensors and connections on it as thats been swapped from the Scenic thats runs well.

So that leaves the lower alloy manifold to head gasket. This was never removed so i didnt doubt it - but its the only place left air can be getting in after the injectors and o rings were all checked and replaced.

Its a bit of a pig to get out as the top engine mount bracket bolts to it in one place. I am ordering a new engine mount anyway as the cheapie i tried is crap so am replacing it with a good Lemforder brand one - ill do it all one go then.

I've never heard of the pressed steel gaskets failing... Maybe it got corrosion from when the engine was sitting on the concrete outside for a few months. It was wrapped in plastic and kept dry and inlet was taped up, but ill find out when i get it off.

jo proffi

1000+ Posts
how does the ecu controll idle airflow?
assuming it has an idle control valve, can it be bypassed and replaced with something mechanical ?


1000+ Posts
what happens when it is disabled?

That was a good thought! Isolate the ecu and let it run just mechanically. Alas the unplugged default butterfly position has it running at 2000rpm.... And the butterfly cant be moved manually.

It occurred to me the lifting hooks are bolted to each of the head, and had the whole engine and transmission weight on them. Enough flex in the head casting to crack a seal on the steel manifold gasket...?

Stay tuned for a few weeks when i have the mount ;)