: newbie here, change spark plugs, 04 CTS?

01-18-09, 07:27 PM
I just bought an 04 CTS, 3.6 motor. I got the engine cover off but am unclear as to how to access the sparkplugs for changeout. What do I have to remove? Please, any help deeply appreciated.


01-19-09, 11:00 AM
Hi Guys,

The overwhelming response is outstanding (sarcasm) but then I realized you probably don't work on your own cars. I work on my Harley-Davidsons and enjoy it. I have tools, that is not the issue and I know how to remove and gap a spark plug. My question is, "What is the correct way to access the spark plugs? Do I have to remove the plenum? Will I need to replace any gaskets on the plenum? Is there a way to get at the spark plugs without removing the plenum? How about some help here, please?
I am on 4 gun Forums and 2 motorcycle Forums and my past experience is that members are willing to share knowledge. I see 18 views of my post and not one bit of help? WTF?


01-19-09, 12:24 PM
Calm down my friend maybe those guys that are looking to your thread dont know how to do the job. Its better for those guys to not talk than tell something that not gonna help you.

Now for your spark plugs! You need to remove your plenum to get acces to your spark plugs. After removing the plenum, remove all individual coil and replace the sparks plugs. For the gasket... If you got the paper plenum gasket YES you need to replace it but if you got the metal rubber gasket, you dont need to replace it. But in my opinion, if you have the 2004 cts and the plenum as never been removed, you got the paper one so buy it its not very expansive. If you need more help dont be shy. Good luck :)

01-23-09, 02:00 AM
Harleypower, there is a search button on the forum. Once done, you'll have a post made by submarineguy that did the sparkplugs change with picture included. there's a lot of results when doing the search.

You'll find some outstanding results my friends!

Its funny how some people wants everything without searching...

11-16-09, 01:17 PM
anybody have instructions or pictures on removing the plenum? i did a search and the post (from 2005) with pictures doesnt really help, since pictures are not in photobucket anymore.

11-18-09, 01:17 PM
Im in the middle of changing plugs & I havent found submarineguy on here. But the information Mugen said was very helpful. HarleyPower i know its been almost a year since you posted this. How was your outcome?

12-30-09, 05:04 PM
I put iridium plugs in my 3.6 and noticed no difference at all.

01-04-10, 07:30 PM
The iridiums didnt fix the problem you were having? Or you didnt see a performance improvement vs a working set of OEM plugs?

03-04-10, 11:31 AM
I saw no improvement in the performance vs a set of OEM plugs that had 95,000 miles on them.
I thought that a new set of plugs would boost performance...Iridium should have boosted it even more.

04-07-10, 12:31 AM
im not sure how much performance you can expect from switching to a more
reliable and better quality plug.