2007 V6 Misfire or Crank Sensor Issue After Harmonic Balancer Swap? - MustangForums.com

V6 S197 General Discussion This section is for technical discussions pertaining specifically to the V6 variation of the 2005 and newer Ford Mustang.

Thread Tools Search this Thread
Old 05-18-2016, 07:24 PM   #1
Thread Starter
Join Date: Mar 2012
Location: PA
Posts: 8
Default 2007 V6 Misfire or Crank Sensor Issue After Harmonic Balancer Swap?

Hi, I am looking to see if anyone has some thoughts on this...

- My 07 V6's pulley/harmonic balancer blew out on a trip last Friday (at 146k). A friend's mechanic was able to get me back on the road quickly. The car is running smoother/better than it has for a LONG time - I think it had issues for a while.
- Not too many miles after, the engine light came on. I drove 350 miles without issue home. I later checked the codes, and had a 300/random misfire, 301/cylinder 1 misfire, and a 0000/unknown. I cleared the codes, on the next trip, it came on again. The car still ran fine.
- Yesterday I changed the plugs and wires (about 70k old). The car did have an occasional hiccup at low RPM for a while, which is now fixed.
- Today on a 100 mile trip, 3 times the car briefly lost some cylinders - highway speed. The engine light was blinking. Each time after a few seconds the car went back to normal and light went off.
- Later, the light came back on solid, with the same codes.

I am thinking the crankshaft sensor may have been somehow damaged, as it is near the replaced balancer (or there could be a problem with the new balancer?). It could be the coil pack too (SD about 70k old) but I find it too coincidental this all happened after swapping the balancer.

Thoughts? Thanks in advance!
rooneyeb is offline   Reply With Quote
Old 05-27-2016, 12:46 AM   #2
5th Gear Member
tx_zstang's Avatar
Join Date: May 2007
Location: Central Texas
Posts: 2,384

The crankshaft sensor could have been damaged by the balancer failure or replacement. But also, check to make sure the connector is plugged into it properly.
Since it 'got worse' recently, check all your plug wires and make sure they are properly seated and 'clicked' onto the plugs. Did you gap the plugs before putting them in?

I have a good used crankshaft sensor I'll sell if interested.

Last edited by tx_zstang; 05-27-2016 at 12:53 AM.
tx_zstang is offline   Reply With Quote
Old 06-02-2016, 06:36 AM   #3
Thread Starter
Join Date: Mar 2012
Location: PA
Posts: 8

Hi, thanks for the reply. Here's the latest...
The plug/wire swap made no change (though the car is running better overall, so the swap was due). Everything was gapped and torqued properly.
I swapped the crank sensor (sorry, I wish I caught your note sooner)- no change.
Swapped fuel filter- same.
Swapped Screamin Demon coil with new one last weekend. Yesterday I was able to get the miss to happen again (driving highway speed in 3rd, about 4-4.5k rpm for a short time)...
So, running out of ideas, last night I re-loaded a preset tune from my SCT tuner (though I had not changed the tune in a long time). So far I have not been able to recreate the problem, but it's too early to confirm anything.

I'll let you know what happens!
rooneyeb is offline   Reply With Quote
Old 06-02-2016, 12:39 PM   #4
5th Gear Member
jwog666's Avatar
Join Date: Mar 2008
Location: wisconsin
Posts: 2,260

you need to take it in and have them perform the crankshaft variation learn using the scan tool. this will "learn" the variations of the new tone ring on the new balancer.
jwog666 is offline   Reply With Quote
Old 06-12-2016, 11:09 PM   #5
Thread Starter
Join Date: Mar 2012
Location: PA
Posts: 8

Thank you! I searched and searched for causes of that trouble code before, and nothing came up about the re-learn. When I reverse searched after jwog666's reply, all sorts of info came up about it. Two mechanics didn't seem to know about this either.

Anyway, the reload of the tune seems to have fixed it - I've driven close to 1000 miles so far with no codes or high RPM miss. But if it does come back I know what to do now. I am only a little over $100 on the mis-diagnosis cost (coil and sensor) so I am still ahead.

Thank you again everyone!
rooneyeb is offline   Reply With Quote

Related Topics
Thread Thread Starter Forum Replies Last Post
Thoughts on 2007 Saleen S281sc Rakatha Saleen, Roush and Boss Mustangs 13 03-12-2010 08:58 AM
2008 Shelby GT500 Ordered: Having second thoughts?? should I do it cheftjpeck 2005-2014 Mustangs 60 04-07-2008 02:04 PM
Food for thought flewbyu GT S197 General Discussion 11 02-24-2007 12:11 PM

crankshaft sensor, harmonic balancer, misfire code

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Forum Jump

All times are GMT -5. The time now is 03:24 PM.