[megankadriver]

HI,
MY CAR is megane 1.4 2001 manual.
about a year ago i had it checked for engine management light came on and he said its the o2 sensors. but the light disappeared so i thot he was just messing around. but now the light came back on again with symptoms:car engine would stay in rev (20~30)x1000 and STOP light comes on every 5 mins when i am driving. is it something to do with O2 sensors? also how many O2 sensors i need and whats da cost? is there any like one at the back other on the front.
c an u pls adv so i know what i am doing. or shall i go and get it diagnostics tested again.
many thanks

 

[S80]

Hi. It is very unlikely that the O2 (or lambda) sensors would cause such a fault. The engine management system can 'tell' if the lambda sensor is telling fibs, and will just ignore it - reverting to a default fuelling profile, which will be close enough to allow proper idle speed regulation.

But to answer your questions, there will be two sensors on your engine - one either side of the catalytic converter. They are £60-ish each, and it is usually the pre-cat one which dies first. Replacement is a simple task for a suitably-equipped garage.

 

[megankadriver]

so in your expert opinion, what is it that can casue engine to stay in rev and stop light coming on when the car gets a little driven?

 

[Recycled Scenic]

c an u pls adv so i know what i am doing. or shall i go and get it diagnostics tested again.
many thanks

Yes I would as it should help take the guess work out of finding the cause of the problem. It could be a combination of several things?

Should you need a new O2 sensor? as S80 says it's the upstream sensor in the exhaust manifold which usually fail 1st. You will need a proper O2 sensor socket to remove it. I usually replace O2 sensors with universal type which are quite a bit cheaper as you have to fit your old plug to the new sensor. Most Renault O2 sensors are the 4 wire type.

http://cgi.ebay.co.uk/NEW-Renault-C...arts_Vehicles_CarParts_SM&hash=item3f078f19e8

 

[megankadriver]

thank, hv been to garage, its the idle control valve. can i repair it or put new one. is ebay good place to buy or partsgateway.com?

 

[Recycled Scenic]

IMO it can be cheaper to buy parts from private sellers on Ebay than car breakers.

You may be able to clean the ICV before replacing it?

 

[S80]

As Recycled Scenic says, Ebay will often be the best bet. There's usually quite a few ICVs on offer at any one time - many will be 'pattern' parts from China which may be of variable quality. Be careful, though - there are several types available which look very similar but are physically incompatible.

You should to be able to hear the ICV operate (briefly) as follows: turn on the ignition for five seconds or so, then off again, without starting the engine. 10 seconds after switch-off you should hear the ICV 'buzz' briefly as it gets re-set by the engine ECU. Listen under the bonnet with the ventilation fan off to make things easier