Hei cap & rotor
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,390
From: At my Bar drinking and wrenching in Lafayette Colorado
On my C4 I changed them out every 100,000 miles whether it needed it or not. I never saw any erosion or wear, or had any ignition system problems, at 100,000 mile intervals. I changed them 4 times, and did not change them when the engine hit 500,000. I sold the car at that point.
Pro
Joined: Sep 2022
Posts: 651
Likes: 508
From: Ohio
If you let the plug gap get too wide, the spark will punch a hole in the bottom of the rotor. Look on the bottom of the rotor for evidence of pencil dots. Check the sides of the coil for over heat rings. They can punch through & go to ground. Examine the cap inside and out for jagged pencil lead looking tracks. Examine wires for hot spots where they cross or sit on anything.
Do you park in a dry garage or in a damp area. Warm/hot cars are a magnet for moisture & ignition problems.
Do you park in a dry garage or in a damp area. Warm/hot cars are a magnet for moisture & ignition problems.
Burning Brakes
Joined: Nov 2014
Posts: 951
Likes: 215
From: Foothills of the Adirondacks.
