I own a 2007 Saturn Aura XR, which now has about 40500 miles. The old spark plugs were fine, and rated good for a 100K miles, but I had them replaced with a set of Autolite XP5263 iridium performance plugs. The old ones were a set of AC/Delco double platinum plugs. I noticed better acceleration and performance out of the new plugs, and the car drives like a dream (Actually feels like a V6 for once.) But I have noticed a considerable trade-off in engine noise. Does anyone have any opinions as to why? Are iridium plugs supposed to be louder? or could they have made a mistake at the shops? (maybe they had the ignition coils put in wrong? and the engine is no longer firing in the correct order?) I mean the car drives very well, but I'm a bit worried about the noise.
Answers & Comments
Verified answer
Spark plugs being installed is basic T/U work, shouldnt effect exhaust noise. My suggestion is first locate sorce of noise. You have a federal mandated emission warrenty on your car for 5 years 50000 miles, provided the manufactures recommended services are done. Im a long time GM mechanic and know the plugs that were put in your car recently shouldnt be used in that engine, and could void the emissions warrenty. Do this, call a local Saturn dealership, ask the service manager after you give him the plug type and number if it would be ok for your cars motor. Dont say they are put in, just you were told they boost performance. Here where I work, its a GM dealer, there are 27 mechanics. Not 1 of the mechanics agreed with the plug choice that was put in your car.
I can see I m late to the party but the reason I m searching this topic is because I ve just installed some Iridium spark plugs myself, and my engine is a lot louder now also? I ve done spark plugs several times before and I ve never encountered this either. Meneke Auto center also just put on a brand new catalytic converter head to tail less than two months ago so I know it s not that. It s just under heavy acceleration that the sound goes from normal to twice as loud now.
plugs will not affect engine noise