hi folks, got a bunch of codes after the restricted performance warning light came on in my 99 xk8. my question: can a coil pack misfire intermittently? one of the codes was misfire cylinder 4 (code P0304) another code (P0354 ignition coil d primary/secondary malfunction). lastly which cylider is # 4 All data claims that the 99 had #1 thru #4 cylinders on each side of the engine (not sure if that makes any sense) any help would be appreciated. i really cant complain. the car has been in service since 10/98 and has been unbelieveably reliable i probably have spent 3000 in repairs with the exception of brakes and tires. previously i owned an 86, 89 and 91 xks all v12's which i purchased new and although they were great cars they did have a few problems. with patience and a 48 month warranty all the bugs were worked out and those cars were fairly reliable and back then you couldn't beat the style or that heavy car feel when driving it down the highway. have a good day steve

 

 

thanks for the info paul, using the red #'s makes it easy. and as i suspected the coil on the passenger side rear is #4. now to find out about intermitent misfire. what happens is she'll run beautiful for awhile then bingo light on and she runs a little rough. alot of times shutting down and restarting resolves the issue (temporarily). any info regarding misfiring would be appreciated. i think what i'll do today is move the suspect coil to a different location and run the car til the warning comes on, at which time i can read the code and see if the misfire occured in the cylinder that i moved the suspect coil to. thanks again paul

steve

 

It is actually quite common for coils to fail intermittently. Performing the swap will likely confirm the bad coil.

 

+1 happened on mine also.