Juddering and cutting out

[the2ems]

My Daughter bought a Megane from a dealer in Cardiff a couple of months ago, and has been having problems with cutting out and juddering at junctions. She has been back to the dealer several times. They have actually kept it for a couple of days twice over the past 2 weeks, each time saying they had fixed it, but each time the problem is still there. Today they even said it may be the plugs, but they would get replaced at the next service. She insisted they changed them, which they did, grudgingly, but they also said that this "problem" was normal on this car. They were actually quite rude to her.
After one visit a few weeks ago, when they said they couldn't find anything wrong, she had a problem with a window not closing so had to call out the AA. She asked the patrol guy what he thought, and he said there was definitely something wrong, and it could be the coil. She went back to the dealer and they agreed the coil was faulty so replaced it. But it made no difference. She is quite reluctant to go back again due to the attitude of the service staff.
Has anyone else experienced this type of problem (the cutting out, not the dealer) and if so, was there a solution?

[AlexB]

The problem with a dealer is, actually more frequent than with cutting out, as the latter affects "only" all 1.6 vvt engines at some stage and the former affects 95% of all Renault owners regardless of the model. If your daughter has been to the dealer who sold her the car three times with the same problem affecting drivability, then she has a right to return this car to them for full refund according to the Sales of Goods and Services Act -- read it.

BTW, am I right that it is a 1.6 model? I guess, you forgot to mention that it also rattles when started the first time in the morning...

[the2ems]

It's 1.4

[AlexB]

1.4-s don't have a rattle attached to the camshaft (as opposed to 1.6). They are simple engines. Try cleaning the throttle body. It is a common problem, which only affects the idle mode. Renault has a Technical Note about it. I can't remember its code, but the garage must know. It is all about removing the throttle body, spraying it with carb cleaner, wiping it dry with a lint-free cloth and putting everything back. It is a 40 minutes job, I guess. The only trick is not to spray electrics and a rubber gasket. My engine is different -- hopefully someone else will come here to help.

What fault codes did the garage "extract" from the engine management computer?

[the2ems]

They said no faults showed up.

[AlexB]

As I understand, both the throtle body which needs cleaning and the TDC (top dead centre) sensor do not show on diagnostics. I would have started with cleaning and then checked the TDC sensor. I hope the garage has checked the colour of the spark plugs. This shows any problems with individual cylinders (injection/ignition/compression problems).

[the2ems]

I have emailed Renault UK Customer Services complaining about the situation, and the attitude of the staff towards my Daughter. Am hoping for response today.

Thanks for the advice.

[andywills]

don't expect too much back from renault uk either i'm afraid

[the2ems]

don't expect too much back from renault uk either i'm afraid

You were right about that. They assured me that customer satisfaction is of paramount importance, and that comments and feedback were vital. Apart from that it's down to the individual dealer

[the2ems]

Renault Customer Services are saying that this is NOT a known issue.

[andywills]

they refuse to admit coils are a problem too