Sounds like a slight miss fire which could be caused by alot of different things!!

Start with checking the simple stuff:

Spark plug condition
Vacuum hoses condition

Let us know how you get on

 

i have changed the spark plug last week and the air fillter has been changed just done 10000
what else could it be ?
some people say it might be coal pack if so how should i find out?

 

As already mentioned, a misfire could be caused by all manner of things. That's half the problem with modern cars, too many sensors etc and if anyone of them goes they can cause the very same problem

I would suggest a diagnostics test as a first port of call to point you in the right direction. I would imagine a local independant garage would only charge an hours labour to do the test!

It's either that or you could end up wasting money by going down the trial and error route and changing all manner of parts that are not the problem!

 

what about if i buy one of those diagnostic scanner which people sell on ebay for £40
would it do the same job as garage?

 

It would but not all cars are OBD compliant, you wanna make sure you get the right one. Maybe someone here can advise further.

I mean, you don't wanna go and spend £40 on eBay on something that doesn't work on your car when the £40 could have paid for a garage to do the test.

 

how should i find out what OBD version my car is using ?and which one should i buy?
and would these device tell me whether is there is something wrong with the coil or sensor or..?

and also the last question ,there is an option on the renault speedometer that show the massages from ECU (i mean the monitor which is showing the fuel usage ,mph,mpg and...)the last option is to show if there is any recorder error on the ECU and mine show "no massage recorded".
does that mean there is nothing wrong with my car ?

there are some link to the items that i am thinking of buying it

http://www.argos.co.uk/static/Product/catalogId/1500001151/partNumber/7402742.htm

http://cgi.ebay.co.uk/Car-Diagnosti...tem150312772814&_trksid=p3286.c0.m14&_trkparms=72:1299|66:4|65:12|39:1|240:1309

http://cgi.ebay.co.uk/Car-Diagnosti...tem150312772814&_trksid=p3286.c0.m14&_trkparms=72:1299|66:4|65:12|39:1|240:1309

http://cgi.ebay.co.uk/UNIVERSAL-CAR...tem200281516866&_trksid=p3286.c0.m14&_trkparms=72:1299|66:4|65:12|39:1|240:1308

http://cgi.ebay.co.uk/VAG-5053-VAG5...tem290284903023&_trksid=p3286.c0.m14&_trkparms=72:1299|66:4|65:12|39:1|240:1318

i will really appreciate ur help
thanks

 

could it possibly be the map sensor?

 

You may have a coil pack which will be a block with either 2 or 4 terminals on it that the HT leads connect to or individual coils that will be like a pen lid connected to the HT leads

You can crudely check these by starting your engine and unplugging the HT leads 1 by 1 while it is running, If you get a massive change in engine running when unplugged then don't worry if there is not much change then this could indicate a faulty coil or HT lead. Be careful not to shock yourself though!!

I recently replaced the engine in my scenic and have had lots of running issue

In the end mine was a combination of a fuel leak and kinked fuel line giving the engine management system erratic fuel pressure readings

I also had a split in a vacuum hose this proved to be the major problem and was promptly fixed with insulation tape!

I would recheck HT leads, Spark plugs, vacuum hoses and any sensor connectors again and again. Failing that put it in for a diagnostic

 

could it be the map sensor which is inside the manifold ,the reason for that is when i look on that black manifold i can see that the map sensor is wobbling in its own place