05 xc90 cracked wires from coilpack..

CainXC · Post by **CainXC** » 08 Sep 2014, 12:29

hey all, getting a misfire cyl 4 code. coils are good, new plugs. but the wires on the connector going into the coil pack are cracked. is there some kind of pigtail i can pick up to replace that section of wire and the connector?

Post by **cn90** » 08 Sep 2014, 19:38

- Remove the cosmetic cover permanently and store it in the garage (together with the Torx bolts).
It makes servicing easier.
That cosmetic cover traps heat, and that helps cook the wires and the coils.
- Get spare connector from ebay or junk yards, then use butt connectors to join the wires together.
Just make sure which wire is which before you cut them.

Post by **cn90** » 09 Sep 2014, 09:28

Another reason for cracked wires is that: when people change spark plugs and re-install the cosmetic cover, if one is not careful, one can crush to wires with the cosmetic cover.

This is another reason to leave the cosmetic cover off permanently.

CainXC · Post by **CainXC** » 09 Sep 2014, 09:35

Thanks for the info. I ordered a new one from the local volvo dealer should be here tomorrow. Looks pretty straight forward. 3 wires. Can't wait to get it fixed.

Post by **cn90** » 09 Sep 2014, 09:51

As I mentioned, butt connectors only.
Soldering is not good for the engine environment (cracked solder joints under engine heat etc.).
Butt connectors, when done properly, are bullet-proof.

CainXC · Post by **CainXC** » 13 Sep 2014, 10:43

So got the connector, cut the wires back about 5 inches. But one of the wires when I cut it back I noticed some of the wire still had green oxidation on it. Would that keep it from firing? Am I going to have to cut the wire back more till I find clean wire?

Stravlr · Post by **Stravlr** » 13 Sep 2014, 15:49

Green=Bad. Will it work, yes; to a point. and will it fail again yes. Best to fix it one time - go back to clean copper. Remember to use Dielectric grease for reassembly.

Post by **cn90** » 13 Sep 2014, 19:29

Green is oxidized copper. It is fine, don't worry about it.
Use butt connector, then add a bit of grease on both ends of the butt connector to keep mositure out.
You will be fine.

CainXC · Post by **CainXC** » 19 Sep 2014, 14:38

Ok Thanks guys. Replaced connector and wire, still getting a misfire. Checked with inline spark tester and it's getting power. So not the wire. I have noticed that inside the spark plug well is dirty in cylinder 4. The other Wells are spotless. Could that mean a leak in the threads for the spark plug?

Post by **abscate** » 05 Oct 2014, 04:41

Unlikely. Possibly a cracked plug, perhaps put a new set in if they are more than half way through their life?

Try moving the coil to a new cylinder and see if the misfire moves with it to diagnose coil vs spark plug problem.