Coil pack exploding!!
 

Hi all, i need some help, i have a 93 wrx, a while ago i was driving up the A24 and all over a sudden i was running on 3 cylinders! I pulled over to find smoke pouring out the bonnet and a sizzling No.3 coil pack!! I replaced it as it was and within 5 minutes it popped again. Now i have changed the spark plug, the ECT ( for a different reason) and the coil pack, but it still only runs on 3 cylinders. Also the rad fans run from start up still, a problem that i thought pointed to the ECT, which i have changed for a shiney new one!!

If anyone can help i would be very grateful

Mike

anyone any ideas???

id get a compression test doen on all 4 cylinders first and then check for any loose/split wires near that coil pack that might be causing a short

i changed the whole pack, it had literally exploded! the new one i put on did exactly the same too, within about 3 minutesof it running, during that time it only ran on 3 cylinders. I replaced the plug and the coil pack again, but its the same, still not right. Where do the coil wires go to?? i see them dissapear under the inlet manifold, but i cant trace them past that. There must be something thats causing this, be it an over voltage to the coil pack, or something, i cant think of anything else it could be!!!! but am i right in saying that the coil packs are directly fed from the ecu????

Cheers Mike

i did a voltage check and the no3 was getting a constant 13.7v, the no1 was only 12.7. Is that 1 volt enough to cause that problem??

The ecu should supply a switched earth to the coil pack and there should be a permanent live to the coil. If there is a short on the switched circuit or the ecu is supplying a permanent earth then it will cause the coil to overload and melt. I may be wrong but i hope this helps.

When i checked with a voltmeter, i had a permanent 12.7 to the No.1 and a permanent 13.7 to the No.3. There was no switching at all, but the No1 coil pack is ok, unless of course that has destroyed itself in a less spectacular fasion!! Thanks for the help and ideas on this, i really need this sorted and sold!!!! i cant afford a dealer, just me!!!!!