Where are the spark plugs on a hummer H3?

Answer 1

The spark plugs are located on top of the engine beneath the plastic cover. There are 5 plugs. The plugs are in line across the top of the engine and are recessed. You must have a 5 inch extention for your ratchet. Because of the firewall on the back of the engine an 8 inch will be too long, but the 5 inch will fit and work. I have worked on several of these engines and the plugs in every engine were nearly burned out ranging from 61,000 miles to 96,000 miles. (gm truely lied to consumers with regard to plug life) a/c delco is the best plugs for replacement but they need to be changed every 60,000 miles if your fuel choice contains ethenol. (lucas tuneup in a bottle works wonders for cleaning the entire fuel system and plugs) be carefull not to over tighten any bolts u may of removed. Go slow watch what you're doing and you wont have any trouble replacing ur h3 plugs. Good luck... Will at dorite motors