Replacing Spark Plugs in GT

[quicksilverdon]

quote:Originally posted by rottone

Well, I replaced the plugs and wires, gapped at .040. It is much smoother, but there seems to be less power so I will try regapping to .045 or .052 when I have a chance. However, I noticed motor oil on the threads of all the plugs I removed, and could see some oil on the spark plug holes. Is this normal? If not, what kind of problem is likely and is it covered by the 70,000 mi powertrain warranty? The car only has 35,000 miles (outside the bumper to bumper).

There are seals on the valve cover for each spark plug hole. They're probably leaking. Unfortunately, you have to take valve cover off to get at 'em.

[rottone]

I regapped the Iridium IXs from .040 back to .050 - what a difference! It feels like its old self again. The low end acceleration was terrible at .040 - it felt like it was bogging, like it was in the wrong gear. It makes me wonder if the performance would be better at an even wider gap, say .055 or .060. Maybe the people who say to stick with Champion coppers for GTs are right?

quote:Originally posted by rottone

I have a stock '03 GT. I am getting ready to replace the plugs and wires with NGK IX Iridiums and FireWires. It looks pretty tight - can it be done without removing any additional pieces? The procedure posted on PTCruizer seems to be for non-GTs. Any advice from experience? Also, I'm trying to decide what the best gap should be for the NGKs - .040, .045, factory .052, none of the above? Any help would be much appreciated.

[SteelBlueGT]

My NGK's are somuch better than the standard copper champions it is not close. Much smoother and yes I kept the factory gap and it has run great for last 24,000 miles.

[forgotten]

If you're Stage 0 then the stock Champions or NGK 4306's will work just fine. Iridium is overkill, and I'm not sold on it's benefits. As you go deeper into power mods and up the boost, you'll find that the car will want to have the gap a bit narrower. This is done to prevent spark blow out. Don't worry, you're not even close. But, If you go Stage 1, you'll probably find that .040 or .038 gapo working better for you.....

[ManyMopars]

[color="Purple"]I just replaced my original Champion spark plugs after 30,000 miles on my 03 PT GT. They old ones were gapped at .060. I had the new Champions gapped at .045. Before replacing the plugs the idle was perfect with no misses. Now I can feel a slight miss, but still feels about the same power wise

[Mean Green]

Originally Posted by ManyMopars

[color="Purple"]I just replaced my original Champion spark plugs after 30,000 miles on my 03 PT GT. They old ones were gapped at .060. I had the new Champions gapped at .045. Before replacing the plugs the idle was perfect with no misses. Now I can feel a slight miss, but still feels about the same power wise

Gap plugs at .040 and buy aftermarket wires, Magnecor, Crane, MSD.

[ManyMopars]

Seems weird, all is fine and just replacing plugs with less gap creates idle miss where none had existed. I used to drag race (Brackets) and found one change at a time helps solve issues. I was thinking about going back out to050, although my other 03 PT GT has always had a slight miss (rough idlle) from new with only 9 miles on the clock, and it has much more power. I have run the same type Champion plug in that one since new now has 36000+.

Thanks for the input. I will have to check the wires at night to see if I am getting an "electrical show".

[Mean Green]

Originally Posted by ManyMopars

Seems weird, all is fine and just replacing plugs with less gap creates idle miss where none had existed. I used to drag race (Brackets) and found one change at a time helps solve issues. I was thinking about going back out to050, although my other 03 PT GT has always had a slight miss (rough idlle) from new with only 9 miles on the clock, and it has much more power. I have run the same type Champion plug in that one since new now has 36000+.

Thanks for the input. I will have to check the wires at night to see if I am getting an "electrical show".

The OEM wires are known to be crap. My new '03 GT had a high rpm miss. I gapped the plugs at .040 and the miss went away.