Cadillac Owners Forum banner

1 - 17 of 17 Posts

·
Registered
2003 CTS 3.2/2004 GTO/2004 GMC Yukon
Joined
·
324 Posts
Discussion Starter #1
Changed the plugs on a customer's 05 CTS last night. First 3.6 I every touched and it was very easy to do. I took a picture of the engine bay with the intake off which I will post later. To get that back bolt out that is a PITA, I removed the passenger side cowl and part of the air box to get better access. This was 4 screws, 1 bolt and 2 nuts extra.... so another 10-15 mins to make removing that bolt so much easier. Would have spent 15 mins trying to find a way to cheat! Not too much to remove on the plenum, itself and it seemed like it was almost impossible to mix something up or forget to put something back. I replaced the gasket as a precaution and I used AC Delco plugs. The car had 3 misfire codes... P0300, P0302, P0303, and it had a bad miss at 6000 RPMs. Swapped the plugs which were well worn factory plugs and what a night and day difference. Car has 124,000 miles on it and it runs really well now. Swapped the air filter also.

If anyone with some mechanical skill is thinking of doing this themselves, I say go for it. You only need a screwdriver, ratchet, 10mm, 13mm, 18mm sockets and a spark plug socket and extensions. If you take the cowl off I think the little bolts were 7 or 8mm. I'll post the pic later today.
 

·
Registered
White '04 CTS 3.6L,Two JL 12w7 + Bose/ Boston Tweets
Joined
·
1,481 Posts
Nice man! how hard do you think it would have been to remove the lower half of the intake? I know this next question is a lil random but how rough were the insides of the intake ports? I just bought a new dremel with some goodies so I may just smooth it all out.

:thumbsup:
 

·
Registered
2003 CTS 3.2/2004 GTO/2004 GMC Yukon
Joined
·
324 Posts
Discussion Starter #4
Trying to remember but I think they were of typical port finish.... certainly dremel worthy. It doesn't look too bad to continue and pull the lower intake out.... not much more to take apart. Go for it!
 

·
Registered
Joined
·
13,969 Posts
also of note is that for 2005 there's two spark plugs and there's not really an easy way to tell which one to use

it is possible that either plug will work just fine (seems that the only difference is a slight gap change)

but if you need to figure out which plug to use on a 2005 engine shoot me a PM, email, or call me with you VIN and I can contact GM to get the engine build pulled up and figure out what plug was installed at the factory
 

·
Registered
White '04 CTS 3.6L,Two JL 12w7 + Bose/ Boston Tweets
Joined
·
1,481 Posts
yea man will I really should get intake spacers from Mace too while Im at it ....:bouncy:

Rippy can you find out what the exact plugs from Bosche I could get somehow? There was a thread a while back but the part numbers didnt match up, I want some Platinum 4's!!! :D
 

·
Registered
Joined
·
13,969 Posts
Cad4Life, not sure exactly what you mean... do you want me to look up what bosch plugs will fit your car? The one aftermarket parts catalog that I use doesn't show any interchange between the OEM plugs and other brands, but it does show a two champions and two densos. Those four plugs show different lists of interchanging numbers. One of the denso plugs had a long interchange list that had two bosch plugs on it. The denso plug was #5339 listed as "iridium power plug, ITV20" the two bosch numbers were #4515 and #HR7MPP302. The gap on these plugs is .044 and i'm assuming that they aren't shown as interchanging with the OEM because the OEMs are gapped at .040

and ultimately I would recommend using the OEMs ... so you're going to pretty much have to take that info and run with it yourself...

unless you were trying to ask something else...
 

·
Registered
White '04 CTS 3.6L,Two JL 12w7 + Bose/ Boston Tweets
Joined
·
1,481 Posts
Yea I didnt know if you were able to find out what exact platium 4's will work...

Guess Ill start searching thanks :thumbs:
 

·
Registered
2003 CTS 3.2/2004 GTO/2004 GMC Yukon
Joined
·
324 Posts
Discussion Starter #11
so to replace the spark plugs i'll need to remove the intake? will i need a gasket as well?
Yes, the upper intake has to come off. You may be able to reuse the gasket, however, for cheap insurance, I would just replace it and not run the risk of being stuck.
also of note is that for 2005 there's two spark plugs and there's not really an easy way to tell which one to use

it is possible that either plug will work just fine (seems that the only difference is a slight gap change)

but if you need to figure out which plug to use on a 2005 engine shoot me a PM, email, or call me with you VIN and I can contact GM to get the engine build pulled up and figure out what plug was installed at the factory
Rippy, I thanked you in the other thread I started about this before I called you about this. If you didn't see it, here it is again.... Thanks for taking the time to look into this for me even though I didn't buy the plugs from you..... (runs and hides under chair)

Funny thing though, the first design plugs were in the car, not the 2nd designs which I bought, which GM told you were the ones in there. I used the 2nd design plugs anyway. They were identical in every way, the only difference that I knew of was the gap, which was .001 difference. The car ran like a beast after I was done with it. Screamed to redline, no more misfire at 6000 RPM's. I called her Monday morning to ask her how the car was running and she was happy. So I am going to guess that you can use either plug with no issues. Thanks again though. If I get anymore side jobs doing plugs in these, I'll give you a call.
 

·
Registered
Joined
·
13,969 Posts
So I am going to guess that you can use either plug with no issues.
i would guess the same (hate guessing though) but now that you have some hands-on experience and have reported back i feel better about it

glad i could help, and don't feel bad 6 plugs isn't going to make or break my monthly numbers :thumbsup:
 

·
Registered
'07 CTS 3.6
Joined
·
2,937 Posts
Is anyone running, or has run a set of E3's in these engines ?

If so, what was/is your opinion ?

Thanks
 

·
Registered
2004 CTS 3.6 , 74 chevy caprice
Joined
·
395 Posts
at autozone ngk iridiums and ngk double platinums are same price which ones are better . bosch platinum plus for a couple more $$
 

·
Registered
2006 STS-V mostly stock
Joined
·
461 Posts
I was JUST considering doing this to my 3.6 - I've gotten a random P030* code once or twice under WOT, but cleared them shortly afterwards and they haven't been back. I decided against it because I'm at best a mediocre shadetree guy. Looks like I may have psyched myself out.

*I think I can I think I can I think I can*

I may take your help and do this next weekend, and if I remember I'll take a bazillion pics to further elucidate on this thread. Thanks WickedGoat!
 
1 - 17 of 17 Posts
Top