Engine Management Light: Engine Misfire

Sully

A question for those who are more knowledgeable on cars. Recently got a 03 Golf, 1.4. Noticed that mostly in the mornings/first start the EML light was flashing at me and the car was a bit sluggish/shaking. It comes on and for a few miles is sluggish but then is fine. It hasn't appeared for a while and even passed the NCT last week. But as of tonight, the light remains firmly on randomly flashing. At times (even in the past) there can be a smell of burning.

Asked the previous owner who said that the light used to always be on but that the garage said it was fine, that there was no error on their computers. She said that on the last service, in the main dealer a few weeks ago, they said the problem was fixed.

Brought it to a mechanic near me who put it on a machine which said that it was an "Engine Misfire" and that meant it was a problem with the finger-coils. He said you would generally buy one (about 80euro) and move it around until the problem is sorted as his computer doesn't say which finger-coil is the problem and it would save buying a few if only one is gone.

Any thoughts?

cgarrad

I bought 4 new ones for a 318ci and no exaggeration it was like buying a new car. Best money I ever spent

They were €120 for 4 Bosch pencil coils from Otto in Tallaght.

cgarrad

http://www.bosch-automotive-catalog.com/public/catalog/products;jsessionid=FpQ_IMtu_tFFdxiveo0A6X-?lgRedirect=true

SouperComputer

Is it rough at idle? Can be easy enough to find which coil\cylinder is misfiring. Disconnect the fuel injector for the first cylinder, if there's no change in how the engine runs then that cylinder\coil is likely the culprit. If the engine runs even worse, reconnect it move to the next cylinder. Rinse and repeat for all cylinders.

Generally the OBD diagnostic will tell you\mechanic what cylinders are misfiring so I'd be wary of a mechanic that say their "computer" isnt telling them which it is. Unless it threw a multiple\random misfire code, even then it sounds like a lazy arse explanation.

Of course if you have the money to do all 4/5/6/8/12 coils then just go and do it, if not then narrow it down using the technique above. Chances are that they will all fail eventually, but how long they will last is anyones guess. Also, when you find the cylinder that's misfiring, leave the injector disconnected if you intend driving it, otherwise the unburnt fuel that gets dumped into the exhaust will cause issues with your O2 sensor and/or cat as well as possibly causing a fire.

Sully

cgarrad wrote: »

http://www.bosch-automotive-catalog.com/public/catalog/products;jsessionid=FpQ_IMtu_tFFdxiveo0A6X-?lgRedirect=true

Cheers, but I cant seem to locate my golf on that site.

SouperComputer wrote: »

Is it rough at idle? Can be easy enough to find which coil\cylinder is misfiring. Disconnect the fuel injector for the first cylinder, if there's no change in how the engine runs then that cylinder\coil is likely the culprit. If the engine runs even worse, reconnect it move to the next cylinder. Rinse and repeat for all cylinders.

Generally the OBD diagnostic will tell you\mechanic what cylinders are misfiring so I'd be wary of a mechanic that say their "computer" isnt telling them which it is. Unless it threw a multiple\random misfire code, even then it sounds like a lazy arse explanation.

Of course if you have the money to do all 4/5/6/8/12 coils then just go and do it, if not then narrow it down using the technique above. Chances are that they will all fail eventually, but how long they will last is anyones guess. Also, when you find the cylinder that's misfiring, leave the injector disconnected if you intend driving it, otherwise the unburnt fuel that gets dumped into the exhaust will cause issues with your O2 sensor and/or cat as well as possibly causing a fire.

Thanks for the advise. I'm meeting mechanic again this evening.