While at a shop looking at a crank no start Cadillac they asked me too look at this Fiesta. The shop owner just said " it runs rough". No more info and it was an auction car. Ive had a few of the 13 and newer Fiesta and Focus with the DPS6 speed that just flatout run rough at certain RPMS and its normal operation. A quick code scan shows no codes and no Mode 6 misfires. I decide to go for a quick test drive and do a VE test to see if we actually have a low cylinder contribution. On our first WOT run at around 5300 RPM the RPM pid goes instantly to O and the car stalls . We get it restarted and have a P0336 CKP performance code. Back to the shop and I quickly connect my scope to the CKP circuit. This is what we have.
Instantly the problem is obvious. I pretty excited because Ive never actually had a damaged reluctor. After reviewing the data its obvious there is a problem at 2 different places on the reluctor as I noted in the screenshot above. I told the shop owner it needs a new crank reluctor. The photos of the old reluctor speak for themselves. The damaged teeth are right beside the nuts and studs for the dual clutch assembly. Someone had the transmission out and did quite the number on the reluctor teeth. A new flexplate fixed this car. I was simply excited to be able to tell the shop owner he needed to do a $1500 job just based on the scope capture.
Thanks for the words Ray. That means a lot. I've always admired your work on here. Quick question. A while back you posted your setup for testing Secondary Ignition on COPs. Your were using pickup coils out of an old Honda distributor. If I just got a distributor from say a 97 Civic, would that have what I need??. Just had a 2013 Mazda CX-5 2.0 GDI with a P0302 intermittent. Igntion swaptronics…
The 97 Civic distributor has 3 pick up coils, but each pick up coil has a magnet embedded, which must be removed. Use the steel brush on a grinder machine to remove the black epoxy to remove the small magnets. I now use small plastic hair clips to hold the pick up coils on to the COPs. You should always use at least 2 pick up coils, one on the misfiring cylinder's COP and another pick up coil on…
Hi Ray, I use the Honda pick-up coils to look at secondary on COP but I haven't removed the magnets in the center of the coils. What's the advantage in removing the magnet? Thanks. E,
I found that I get a more accurate burn voltage on all makes of COPs with no magnet in the in the pick up coil.
Interesting, I'll have to remove one and do some comparison. Thanks.
OH MY.....and awesome job diagnosing!!! For those who still swear and argue that a scope is NOT necessary, this post should be enough proof that it is!!!
Nice find, I haven't seen this, but not surprised with all of the transmission removals for clutches. I have had vibrations from improper torque sequence that had to be loosened and realigned.
Thanks Chris. I also had a 16 Focus 20k miles with a vibration at 1000RPM. Someone had recently been in the trans. I verified it was a vibration. I hate NVH probably because I don't have the correct tools for it. After motor mounts cutting it in half , I drove to the local Ford dealer and a tech said" loosen the clutch nuts, wiggle the engine back an forth at the balancer bolt an retighten"…