The message to which you are about to reply is shown first. GO TO REPLY FORM



 VIEW    REPLY TO THIS MESSAGE    PRINT   SAVE 

Bad coil/s - misfire V70-XC70

posted by  16Victor on  Wed Oct 15 13:38 CST 2008
Author: [PROFILE] [EVERY POST] [THREADS] [BEST POSTS] RSS Feed     [IGNORE ALL POSTS]
last visit: Sat Mar 5 14:18 CST 2011
[RELATED]

OK, did a compression check because of some symptoms (slightly rough idle, v. slow coolant use). Found #5 to be low. Buttoned it up and drove it, 1/2 later I'm getting a big miss and it's throwing codes for #5 misfire and cam position sensor issue.

I figure the #5 low compression is due to the rings getting carboned up from a failing coil. More on that later.

I'd pinched the cam position sensor wires under the cam cover (due to the harness sleeve being disintegrated). Soldered in patches for both wires and tie-wrapped them out of the way. That solves the cam position code issue.

During this time I determined #5 coil to be dead (verified via watching and swapping) and replaced it with a new one.

Drove it 40 min. tonight - running great. Accelerating from a light, it starts to misfire bad. Throws a #3 misfire...wth? Clear that code (yes I carry the frigging code scanner with me) and limp it home, missing badly.

At home, I see it's got a code for random cylinder misfire.

Also it gives me that burning plastic smell which I figure is from the now-fully-exposed wires over the cam cover.

Going out now to meter and test all the coils but was wondering...

- do coils fail all-of-a-sudden or gradually?
- did I reassemble something wrong, causing additional coils to fail?
- is there a driver circuit in the ECM that could be failing?
- any other thoughts?

Will post more after I diagnose more...tia,

Ron

PS '99 V70XC, 137K miles, Volvo brand plugs (prob new at 96K when I got the car)






USERNAME
Use "claim to be" below if you don't want to log in.
PASSWORD
I don't have an account. Sign me up.
CLAIM TO BE
Use only if you don't want to login (post anonymously).
ENTER CAPTCHA CODE
This is required for posting anonymously.
OPTIONS notify by email
Available only to user accounts.
SUBJECT
MODEL/YEAR
MESSAGE

DICTIONARY
LABEL(S) +
IMAGE URL *
[IMAGE LIBRARY (UPLOAD/SELECT)]

* = Field is optional.

+ = Enter space delimited labels for this post. An example entry: 240 muffler


©Jarrod Stenberg 1997-2022. All material except where indicated.


All participants agree to these terms.

Brickboard.com is not affiliated with nor sponsored by AB Volvo, Volvo Car Corporation, Volvo Cars of North America, Inc. or Ford Motor Company. Brickboard.com is a Volvo owner/enthusiast site, similar to a club, and does not intend to pose as an official Volvo site. The official Volvo site can be found here.