milky 0 Report post Posted August 7, 2010 (edited) Hey all. I have an e46 320 with the M54 engine. Recently it through the check engine light and has begun mis-firing. The diagnostic plug says mis-firing on all cylinders but most commonly on 5. Unplugging any coil causes it to run equally worse, none of them including 5 has no effect. We put coil 5 in an M50 and it caused it to run slightly worse but not as poorly as the e46 (very hard to tell it doesn't run very smoothly anyway), and the coil from the M50 had no effect when put into the e46, we couldn't swap them all because they didn't bolt up and we were holding them in. From my understanding it would be unusual for all six coils to die at once... It has the platinum plugs which have been in there quite a while, is the central probe supposed to extend above the porcelain piece? The NGK catalogue says a 0.5mm gap and its way larger than that between the 4 bits that stick up and the central probe so perhaps it needs new plugs? Any help is much appreciated Cheers Taylor edit: the middle probe is level with the porcelen unlike this one ... or are they suposed to be like that Edited August 7, 2010 by milky Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted August 7, 2010 The plug in the picture is an early plug... not the type fitted to your car. By fiddling, you are introducing more error codes. You will need to clear the fault codes, road test and recheck. The missfire error code may not be plugs or coils. Get it checked professionaly with a scanner & a technician with a brain. Quote Share this post Link to post Share on other sites
milky 0 Report post Posted August 7, 2010 it has been checked by a friend of mine at mc-millans, but today i bought and replaced the plugs, new ones are also flat. it has power under foot now but still doesn't idle smooth. there is oil all around plug 6, so will have to do the rocker cover gasket Quote Share this post Link to post Share on other sites
*Glenn* 854 Report post Posted August 8, 2010 If he's a technician there he should be more than capable of sorting it for you. Oil in the spark plug tubes (leaking rocker cover) needs to be attended to as well to prevent the coils firing to earth, which can also damage the coils. Quote Share this post Link to post Share on other sites
milky 0 Report post Posted September 3, 2010 plugged diagnostic back in. Camshaft sensor is buggered Quote Share this post Link to post Share on other sites
