2001 Volvo V70 T5 Misfire/Tick

2008XC70 · Post by **2008XC70** » 01 Jan 2015, 18:37

Interesting story. I was diagnosing a misfire along with a tick on a 2001 V70 T5 with 124k miles.

Plugged in the dice unit and showed cylinder 5 misfire. I pulled the top plastic cover off and noticed that exhaust and moisture was shooting out of the number 5 coil pack breather hole! I pulled the coil pack, everything looked normal until I pulled the plug.

The spark plug had failed internally and on each compression stroke, the core jumped up allowing combustion gases into the spark plug well and out the vent hole of the coil pack. Then on the exhaust stroke, the core would come down onto the tip of the plug and make a metallic sound. This also destroyed the bottom of the coil pack and boot. Funny thing, these plugs are Volvo brand and not very old.

Replaced with new plug and new coil pack and all is well again. I've seen many different issues with plugs and coil packs and this a first for me. I wanted to post this from beginning to end in case someone else ran into this same situation.

Post by **vtl** » 01 Jan 2015, 19:15

Was is OE plug? How many miles on it?

2008XC70 · Post by **2008XC70** » 01 Jan 2015, 20:24

Oe plug, couldn't be more than 20k miles