Help req'd please with mk3 clio misfire

[DaveLiquid182]

My wifes 2007 1.4 mk3 clio has just developed a slight misfire. Also the EML is flashing intermittently. After a good search (not just on cs) a lot of posts seem to point to a faulty coil. I was just wondering if anyone else could add to this possible diagnosis as i dont want to go out buying coils, plugs etc etc and just waste money.

Cheers

 

[olliewebbuk]

That engine runs pencil coils. With the car running keep unplug each coil one at a time. If the engine stutters and struggles more, that coil is fine. If it doesn't change then you've found your faulty coil.

They're about £45 each last time I had to buy one.

 

[Sean6545]

That engine runs pencil coils. With the car running keep unplug each coil one at a time. If the engine stutters and struggles more, that coil is fine. If it doesn't change then you've found your faulty coil.

They're about £45 each last time I had to buy one.

You should never unplug pencil coils when the engine is running. The correct way of diagnosing the fault with coils is to undo them all from the head and pull them off the spark plug one by one to find the faulty coil.

 

[MicKPM]

Nagh, let them carry on and blow theECM's coil drivers Shep... sometimes learning the hard way is the only way people learn

Ideally it needs diagnostics to say exactly what is causing the missfire and on which cylinder as it could be a coil but it could also be an injector (Though my money is on the coils). One thing you can check yourself with ease is the spark plug wells to see if they're filled with water or oil especially if the car has recently been cleaned by one of these cheap and cheerfull car wash places.

Mick

 

[olliewebbuk]

Meh. It's how the RAC/AA last checked on my two previous cars with a K4J.

 

[MicKPM]

Ollie, in most cases you will get away with it but there's always going to be a time when it sends a spike back to the ECM and pops the ignition driver relays or burns the PCB tracks out.

 

[DaveLiquid182]

Ive put a fault code reader on and it said number 4 cylinder misfire. I've pulled all the coils and plugs out. Coil and plug on pulley end was rusty so I changed the plugs. Still the same so will b changing coil on Monday.

Cheers Mick

 

[olliewebbuk]

Ollie, in most cases you will get away with it but there's always going to be a time when it sends a spike back to the ECM and pops the ignition driver relays or burns the PCB tracks out.

Noted Mick. I'll be in touch about some work on my car I emailed you about a while back, work is pretty busy right now so getting time off is hard.