[bencummins]

Hi Guys,

Our car has just start misfiring, and showing the "Check Emissions" error on the dash, it goes ofter after a couple of minutes and then comes on again a while later.

I've plugged the laptop in and checked the fault codes, and its showing P0302 and P0300 - I've been reading around, and searched these forums, but not really sure what to do.

I have checked the plugs, and they've a little carbon build up on them, but have cleaned them, and it seems the same. I have also tried running the car with each coil in turn disconnected... it seems to run just as bad whichever one is disconnected.

I understand the P0302 code is telling me its cylinder 2, but the P0300 is a "random" mis fire... I couldn't get the OBD device working before I started messing around with the coil packs, so not sure if its "random" as I was switching them around, however, it is persisting with the P0302 code.

Also, I have a confession to make - the car has been due a service for a couple of months now, but I have been stupidly busy with a project at work lately and havent had the chance to take it, but will be going in the next week or so.

So, I have a few questions....

1) Do you need to actually clear fault codes, or if I move the coil packs around, and one is faulty, will the error code move around to? If I need to reset the code, how do I do this? I have tried using the "Reset Codes" in Easy ODBII and in a couple of other programs, but it doesn't seem to clear them.

2) I have read around about the P0300 error, and the main website I found, http://www.random-misfire.com/, has me worried that it could be a more serious issue like a head gasket.... I did notice earlier that the radiator coolant is a bit lower than normal.... but im really hoping this isnt the issue.

3) The car tells me the oil levels are fine, but also reminds me it needs an oil change - could this have caused the issue?

3) Anyone have any other suggestions of things I can look at?

4) Can anyone recommend a mobile mechanic in/around the southampton/bursledon area?


My current plan is going to the auto factors tomorrow to get a full set of coils to see if that solves the issue.


Thanks in advance.

Ben

 

[madnoel10]

Disconnectng each coil in turn is not a good test for finding which cylinder (if any) is misfiring. The coils are wired in pairs so when disconnectig one its partner also tends to cut out.

Disconnecting each fuel injector in turn is a better method of tracing a misfiring cylinder. In fact you may ahve a faulkty injector and spending money replacing the coils may be a waste of money.

Try and find the fault first before replacing parts.

Judging by your fault codes it is possible your code reader may not be Renault friendly - Renault use a different protocol so not all readers are compatible.

 

[bencummins]

Thank you for the reply, are the fuel injectors easy to get to? Can I test myself? If so, I will give that a go in a little while