1998 Taurus - transmission problems and other oddities

I've got a 1998 Taurus that, over the past few months, has been exhibiting some strange behaviors.

Maybe about two months ago, I was driving home from college with a friend when, out of nowhere, the spedometer dropped to 0 and the cruise control stopped working. I immediately pulled to the side of the road, worried that something was wrong with the transmission (I had had some bad experiences with my first car, a great 1987 Crown Vic), but soon realized that the car drove fine; the spedometer had just quit. I pulled off at the nearest exit to get out and check fluids, and while turning around on a side street I noticed the power steering acting funny -- sometimes it would be there, others it just wouldn't. Once I got the car home, my dad took it on a test drive to the grocery store only to find he couldn't start it to get it back home. We replaced the battery, as well as located and repaired a bad starter. Finally, all seemed right again in the world. It seemed odd to me that a new battery and starter fixed this problem, but I wasn't asking questions.

Just last week, however, I took my car out one night (now back at school) to find the same problem rearing its head: the spedometer quit shortly after I got out of the parking lot. Power steering was being weird again, too. I wasn't too concerned, though, since nothing else had been affected last time, until I noticed that the transmission was doing funny things, too -- shifting hard, running up to 4000 rpm before shifting into 2nd. I was less than pleased. I checked the transmission fluid (as well as the guys at Jiffy Lube), and nothing was wrong there.

So the question is, what's up with my car? Should I be concerned about paying a hefty sum for transmission repair or even replacement? I've poked around on the forums and noticed similar stories ending with bad vehicle speed sensors -- could this be my problem rather than the transmission itself? If so, how much should I brace myself to pay?

I'd be much obliged if anyone could help a poor college student out. Thanks so much, and please excuse the length of my post. Just want to get all the necessary facts out there.

[djcalli]

Hello, I have a '98 Taurus SE that experienced the same problems; speedometer quit, would not shift properly, and loss of power steering. Found it was the Vehicle Speed Sensor that needed replaced, cost about $300.00 to replace.

[Doohickie]

You may want to see if there are any engine codes. I was thinking of a speed sensor as well. Also, you didn't say what led you to change the battery. If you think it was running down, the low voltage may have contributed or even caused the problems you saw. If the new battery is also giving out, your problem could be your alternator. One failure mode of the alternator is that diodes that are supposed to allow current to charge the battery can fail allowing current to leak back from the battery through the alternator coils and discharge the battery. When a new battery dies quickly, the next thing to replace is the alternator.

So I guess you have a couple things to look at: speed sensor and alternator. Reading the codes may point to one or the other. Also, if you take the alternator out of the car, many parts stores can check the alternator performance on a bench tester that will check how will it's charging and whether the diodes are working properly.

[jbogal]

I just went through the same thing-MAKE SURE YOU REPLACE THE WIRES GOING INTO THE SPEEDSENSOR FIRST!!! 99% of the time its those wires that get bad not the sensor itself!! If those wires are even a little freyed,you will get a fault code for the speed sensor.This is my 2nd taurus and all both the same problem and every single time it was the wires that plug into the sensor.And to one of the above comments,you paid $300 to replace the speed sensor?? the part only costs $40 or less anywhere you go and takes less than 10 min to install!!!

[Jmiller]

I'm curious, do you know where this speed sensor is located so I change it out? I have all of the same problems you had that started yesterday. Thanks, Jmiller

[shadowmansm]

I have had both the same problems, turned out the first part was the alternator was going bad, messing up the power steering and a leak in the vacuum tubing causeing problems with shifting....!! Try those....

[Drphish01]

Could also be a combination of 2 issues, the V.S.S. should have nothing to do with the power steering. I have seen the same shifting issue combined with the spedo & cruise be caused by the Transmission Range Sensor. This can cause all sorts of problems, but I have also seen a faulty alt. cause the same type of concerns. Sometimes it may be more cost effective to have a factory trained tech diagnosis this for you, otherwise your pocket book goes down with each new part and your parts store just gets more money... Just something to think about. - Phish