Has my coolant temp sensor gone ??

[Briv6]

I had a coolant change and afterwards the needle didn't go back to the middle, it sits just under the middle line and jumps up to middle and back down frequently . Today the emissions light flashed on start up then disappeared The car sounds lumpy on idle but it might be exhaust noise it sounds like it's stuttering . It's intermitent as the car can idle normal and then change in the same journey . Before Christmas I had the emissions light come on and plug in told me was lamba but car never showed any symptons and light never returned ..
Coolant changed and now it runs a bit rough but I'm wondering if it's maybe hole in exhaust or the join .
getting it put on clip this morning but would maybe rather go buy a coolant temp sensor if I was convinced thst was my problem or fiddle about with it

 

[Wilky0302]

Needle fluctuation sounds like air in the water system to me!!

did you run it up correctly bleeding the air from the system?

 

[Briv6]

I didn't do the coolant change myself . someone else suggested to me about air in system

 

[Briv6]

Would this cause the car to sound rough and put emissions light on ?

 

[reedy107]

Would this cause the car to sound rough and put emissions light on ?

I would say yes. Rule of thumb is ecu reads coolant temp aswell as other sensors and adjusts mixture to get the temps up quicker. It will do this by making the mixture richer.

But then if the sensor is faulty the ecu will always be running the engine rich and the lambda want like this as the A/F ratio will be out of spec so will flick on the emmisions light.

Im guessin the light doesnt come on for the first 5/10 minutes in the morning. Maybe a bit longer.

 

[Briv6]

The light flashed on start up a few times yesterday on long journey but few flashes and off , never stayed on or appeared during a journey

 

[reedy107]

Could be a faulty lambda ?

 

[Briv6]

Clip found it to be one of my spark plugs not tight enough , not happy as they were fitted by Renault tech few days ago as a homer .

 

[reedy107]

not tight enough ??? !!!!! WTF

It must of been not even screwed in at all for it to run like a bag of s**t lol


good old renault