Intermittent: tach drops to 0, car jumps & bucks

[Amy 95 SHO]

I can't be sure, but I believe that my SHO is the only gen 2 that my local ford dealer has worked on.

3 years ago, was having a problem with my 95 SHO not wanting to start at times. I'd be running errands, the car could start several times, then suddenly not start. I'd wait a few hours, then the car would start -- no problem! After bringing it to my local dealer several times, getting this and that replaced, or having the dealer have "no idea", was advised by a private "good 'ole mechanic" to tell the dealer to replace the crank shaft sensor. Upon my demand they did so, and starting problem stopped!

Jump ahead nearly 3 years. A new problem has started. Again, this is an intermittent problem. The car starts just fine. Twice now, while driving the car, the "check engine" light goes on at the same time the tach drops to zero, the car jumps and bucks, not responding to the accelerator. Both times this happened, the car had already been driven, turned off, restarted, and all was just fine.

Brought the car in to my local dealer, their mechanic says that it is the crank shaft sensor -- sorry, there was only a 2 year warranty on the one put in Dec 2013!

I've read thru some older posts on this site, and it sounds from those posts that it is more likely the cam shaft sensor!

My local dealer has it setup so the customer and the mechanics never actually speak. They have a "go between" who, like me, only has minimal knowledge of mechanics, he just reads what the mechanic wrote, so any questions go thru the "go between". I asked the "go between" to check with the mechanic -- was it the crank shaft sensor? Or did he mean cam shaft sensor (since the crank shaft sensor was not even 3 yrs old)? Did he check wires? Etc!

The "go between" got back to me with no new info. So far, I'm $100 in, with an answer that it will cost another $1,500 to re-fix something that I'm not confident is the actual problem!!

Any advise!

 

[luigisho]

You can actually replace the cam sensor yourself. I'm looking for the write up with pics but I'm having a hard time finding it. You get extensions and go through the wheel well with the plastic liner still in place, access the 2 fasteners on the sensor, and remove and replace it. It seems difficult but is really pretty easy. Especially with smaller hands. Anyone have a working link??

 

[rubydist]

the tach dropping to zero is not due to the crankshaft sensor on these cars.

It is nearly always a cam sensor that causes the symptoms you describe. As luigisho pointed out, it is not difficult at all to change it, and its a $25-50 part depending on where you buy it. It takes (iirc) a 5.5mm socket or wrench and the ability to disconnect and reconnect one wiring connector.

 

[Amy 95 SHO]

Although I was on my Husbands "pit team" back when he was straight racing his 74 Charger, the most I did there was replace the road rims w/tires to the track rims w/tires -- more often just rolled the respective rim/tire set to him to replace! Way, way back, I replaced the voltage regulator and a rear side window on an old VW bug - super, super easy stuff!!

On the other hand, my husband still does some simpler work on our cars (not so much on the SHO -- more his Charger and our 56 Coronet), but with the info he may be up for replacing the SHO cam sensor!

Thank you so much for the info, luigisho! If someone does have that link, I can show my husband to see if he is interested in doing the work!!

 

[Amy 95 SHO]

the tach dropping to zero is not due to the crankshaft sensor on these cars.

It is nearly always a cam sensor that causes the symptoms you describe. As luigisho pointed out, it is not difficult at all to change it, and its a $25-50 part depending on where you buy it. It takes (iirc) a 5.5mm socket or wrench and the ability to disconnect and reconnect one wiring connector.

Thanks! Everything in my gut was saying it couldn't possibly be the crank shaft sensor!! The car is still sitting at the service centet of the dealer lot. I wanted to wait until I heard from some folks that were more versed in the SHO!

 

[luigisho]

Look at the rear bank camshaft location and you will see the black roundish sensor with the wiring plug on it. It's unplug the harness and 2 fasteners to remove and reverse to put on a new one. The only trick is it's so cramped in there. You guys can get out there with a flashlight and for sure do it on the cheap. I also forget the exact fastener if it's a hex socket or a star drive or whatever but it's easy enough to look at it and figure out. remember try and angle an extension or two through the wheel well area instead of a right angle or stubby wrench from the top. Very little hand room at that location.

Figure 3 if the page will open http://www.autozone.com/repairguide...MS/Component-Replacement/_/P-0900c152802791af

Don't listen to all that removal stuff in the directions though

 

[Amy 95 SHO]

Look at the rear bank camshaft location and you will see the black roundish sensor with the wiring plug on it. It's unplug the harness and 2 fasteners to remove and reverse to put on a new one. The only trick is it's so cramped in there. You guys can get out there with a flashlight and for sure do it on the cheap. I also forget the exact fastener if it's a hex socket or a star drive or whatever but it's easy enough to look at it and figure out. remember try and angle an extension or two through the wheel well area instead of a right angle or stubby wrench from the top. Very little hand room at that location.

Figure 3 if the page will open http://www.autozone.com/repairguide...MS/Component-Replacement/_/P-0900c152802791af

Don't listen to all that removal stuff in the directions though

Thanks!

 

[itwonder]

See if the Cam Sensor cavity is full of oil once you remove the old sensor; indicates a cam seal leak.