: Ignition Coil Replacement 2005 STS 3.6

05-10-12, 07:54 PM
I recently took my STS into the dealer because the check engine light was coming on from time to time. They said that the scanner said misfire in cylinder 3. They said that possible causes were ignition coil, ECM, fuel injector. They recommended doing the coil first as it was the least expensive of the 3. Does anyone have the procedure required to do it myself. I know where it is located, but concerned that I may have to remove the upper intake manifold.


05-10-12, 09:08 PM
NO! you don't, there are semi-covers on each valve cover,
your coil-on-plugs are located under there.
Never did it on a Cadillac,so can't help you with the procedure !
Blow our each area,with air, to prevent dirt, or debris, from getting into
the cylinder if you remove the plug.
Good Luck

05-16-12, 12:11 AM
the intake manifold is pretty easy to remove. i recently changed my plugs and all i needed to do was loosen the bolt on top of manifold and the had someone slightly lift it for me to take the coil off. taking the coil off is as easy as unplugging the wiring and then 1 bolt to remove.

my car was sputtering occasionally and lagged when i stepped on the gas on freeway, in addition to the engine light going on and off when i stepped on it. the change of plugs didnt help. i am guessing i have the same problem as you, just been lazy to take my car in to find out which cylinder is misfiring.

hope this helps, please reply with your results. good luck!

05-20-12, 04:52 PM
Hey I was seeing if you had any luck changing that coil yourself? I am having the same issues with my 05 STS and I was going to just do it myself and hope that would take care of the problem. I am way under the 100,000 mile tune up so didnt want to pay $600 for a tune up at cadi if its not needed at this point. Please let me know what you found out...it would really help me out big time.

01-22-13, 01:31 PM
Where is the number 3 coil?

01-22-13, 01:41 PM
Where is the number 3 coil?

Middle of the row on the passenger side

01-22-13, 05:03 PM
Sorry, I jumped the gun on this one, I missed your heading
for a 3.6, I responded for a 4.6 V8 !

01-23-13, 12:47 PM
I just did mine 3 weeks ago. Here is the Video I found that helped: http://www.youtube.com/watch?v=metBNZYKv1Q Good Luck!

07-31-13, 08:10 PM
Anyone know where is cylinder #4? 2005 sts v6. Thanx in advance

08-01-13, 01:23 PM
Anyone know where is cylinder #4? 2005 sts v6. Thanx in advance

Middle on drivers side. BTW on the 3.6L DI engine you DO NOT have to move the throttle body. I just did all my plugs.


My bad I meant intake manifold, not TB.