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2004 HUMMER H2 Base 4dr Wagon

2004 HUMMER H2
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4-Wheel Drive, 4 Door Wagon
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April 15, 2009, 2:39 pm


Question: changing spark plugs

Do the spark plug wires just pull off as standard wires do, or is there some trick? I don't want to damage the wires if possible.

May 9, 2009, 5:23 pm

Anthony Z

The 2006 H3 doesn't use the old traditional spark plug wires. There are 5 individual ignition modules under the intake plenum that have to be removed via a single 10mm hex headed bolt. The the bolt is loose the entire module slides up off of the spark plug (there is a boot of sorts that goes over the plug. Before installing the new plugs, be careful to compare the overall length to the stock ones. When I did it, I noticed the Densos I bought were about an 1/8" shorter. Because the ignition modules have a contact spring similar to that in a flashlight, the contact would have been unreliable at best. Make sure you feel the spring compressing when you reassembly or a misfire could result. FYI, I ended using the AC Delco Iridiums. It runs like a top. Have 111 K and still going strong.

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