My son drives my wife's old Saab 9-5 ('07) which is subject to periodic replacements of the DIC (discharge cassette that replaces the coil and distributor.) The Saabnet gurus say to replace the plugs at the same time that you replace the DIC as the system depends on feedback from the spark plug. The Saabnet experts also say to only use NGK plugs. I put iridium spark plugs in the car maybe 15,000 miles ago, thinking that they would last another 40k, but I decided to change the plugs today, putting in platinums.
The old plugs had porcelain which was white. Do people still read spark plugs to determine the car's condition? Because this car had a lot of burnt oil on the threads. Is that something to be concerned about or is that just a valve cover gasket, or something similar? Should I have kept the iridiums?
The old plugs had porcelain which was white. Do people still read spark plugs to determine the car's condition? Because this car had a lot of burnt oil on the threads. Is that something to be concerned about or is that just a valve cover gasket, or something similar? Should I have kept the iridiums?