Spark Plugs for Base 2003 PA


New member
Buick Ownership
2003 Buick Park Avenue
Looking for the best replacement spark plugs for my 2003 PA. Have used Bosch 2+ Platinum and AC Delco Iridium plugs in the past. Currently, I am using the AC Delco Iridium plugs for about 50,000 miles and have experienced a misfire on cylinder number 5 when the weather is wet. Probably will be replacing the wires at the same time. I would appreciate any referrals and suggestions for the best plugs and wires to use. Thanks.


Full Member
Buick Ownership
2007 Lucerne CXL. and 1995 Lesabre currently, past 1973 Riviera, 1968 Riviera
Nothing wrong with AC Delco Iridium plugs as they work well. Plug wires again sticking with OEM AC Delco will be fine. Most problems come from buying low priced or poorly made Ebay - Amazon "high performance" knockoff parts. If you get 5 + years out of the parts and no problems it's worth the price on the OEM.

Before you change out your current set, if it's moist out, run the car in a dark area and check for any shorts sparking that should show up just to confirm.


Well-known member
S.W. Ontario Canada
Buick Ownership
2018 Regal Sportback - 2010 Yamaha R6 (track bike) Past cars: 92 LeSabre, 98 Regal, 02 GrandPrixGT
I've used NGK TR-55ix / 7164 (iriduim) and they last forever. Verify gap is 0.059"-0.060"

New plugs torque to 18 ft/lbs.

Anyone re-installing used plugs should not exceed 13 ft/lbs (11 to 13 ft/lbs is good) because the crush washer has already been crushed.
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