0 RPM hard shift

**Logan541** · 07-24-2012

I was driving along at about 75 car made a hard shift, kept doing 70 but RPMs dropped to 0. got to my destination ok (about 25 miles) shut it off restarted it stalled, restarted again but still 0 rpm. Shut it off waited about a half hour started it right up RPMs were normal. Drove 35 miles no problem 4 hours later drive for about 6 miles fine then at a steady 55 with cruise set 3 hard shifts each time tach goes to 0 but then comes right back up after third hard shift it ran fine the rest of the ride home. Any ideas I need this car for work Friday morning.I am leaning towards crank position sensor or cam sensor. But my local shop says he does not think so because there are no codes being thrown. Help guys. You have saved my butt before and I need you guys again. It is not misfiring. Also when I shut it off this morning (before any problems) it gave a gasp type sound from the lower right side of engine (I had the hood up and heard it) ICM has already been changed along with coil packs (This problem happened on a much larger scale 8 months ago car misfired as well and stalled abs lights and brake light came on and had to be towed when they started it next morning it started and ran fine they took it for a long ride until the problem reappeared )that is what they changed.

Thanks again

Logan

**FordMan77** · 07-24-2012

I'd say replace the crank position sensor. They don't always throw a code and the dropping to 0 RPMS while driving is a sure sign. When you say "hard shifts" while you have the cruise set at 55mph, how can that be? Wouldn't you already be in OD? I would think this is the car dying and catching itself (bucking) more than a hard shift.

**BillBoost37** · 07-25-2012

Agreed

**Logan541** · 07-25-2012

Thanks guys that is what I am going with, I chose a AC delco over BWD should be here tommorrow

**Logan541** · 07-27-2012

Changed sensor and I do believe that was the problem, car just seems to shift smoother in general and I noticed the RPM's seem more steady. However I do have a question how does that sendor work? I mean I am trying to figure out why I had some days it would buck real bad and die and would not even start then the next morning it would start and run for weeks ok then I would have days where every day it would be a ***** to start the RPMs would bounce to almost 3,000 then to 0 several time then it would smooth out and run fine for a whole day. So I am just confused as to how that thing works and controls the crank (I am one of those I need to know answers guys, drives me crazy) And Ford man and Bill thanks a bunch

**ericg1181** · 07-28-2012

maybe the crank sensor was bad but here was the same problem i had. i was driving and it would almost seem to misfire and have a hard kick and my tach would drop to zero sometimes it would throw a code sometimes it wouldnt. i had an electrical diagnosis done and found my crank was sending a signal to the icm but the icm wasnt processing it so i changed the icm out. which mind you is a cake walk.

**Fivefingerdeathpunch** · 07-28-2012

crank sensors just like to be strange, they will work great and then just have a problem, then work great and then have a problem again. Something inside the sensor goes bad and stops the signal.

**Logan541** · 08-03-2012

thanks fingers. I wanted to change this a year ago but two different shops kept telling me it was something else. This time around I change the sensor and the car is running fine but I guess time will tell. In the meantime I ended up changing the ICM, wires plugs, batter cable, alternator, MAF twice, TPS, IPC, some other sensor IPC or something like that, seafoaming it, fuel pump ($399.00 ouch) coil packs. damn that hurt when I had a gut feeling I was right all along. Thanks to all you guys on the forum.

**Logan541** · 08-08-2012

HELP!! Sensor was not the problem totady at about 50 mph car gave what almot felt like a pop very slight I thought it was a regularshift. I looked down RPMS were ar 0 atayed that way about 2 tenths of a mile I started to pull over and Rpms went back to normal. Any ideas ?