Here is the deal: going down hill in overdrive or 3rd, when you let off the gas pedal or touch the brakes, the RPM will stay steady but the speedometer needle will zero out then climb to speed your actually traveling and then fall to zero and repeat until the car decides to get its act together. I pump the gas a little and it helps, but I don't notice it changing the RPM until the "catch on feeling" and were going again. For a while, it would not do this on any regular basis, now it's doing this often. The engine will sometimes die going down hill, around a tight curve ( anywhere you need to suddenly back off the gas or tap the brakes) or if you have to stop short. Now, for the first time it acted as if it would not shift down when I came to a stop, starting off as if it was in high gear. Most of the time on flat ground it shifts hard and no slippage even when I stand on it. The "tranny" fluid is Amsoil and full and the filter is new. THANKS A HEAP - Ol' Tom
Hi and welcome to FixYa,
Initially, check the wiring/connectors to the speed sensor. The speed sensor is at the transmission would look like the image below.
Incidentally, the speed sensor not only sends signal to the speedometer, is signals are also used by the engine computer and the transmission control. This would partly explain all the other concerns.
Check and perform preliminary visual or necessary inspection. Pls post back result(s). Good luck and Thank you for using FixYa.
Speedometer started going crazy then stoped working altogether
I changed the speed sensor but no change. Auto zone sold me a cable only problem I can't find out where it goes I've looked all over
the place! does this mini van 1997 Olds silhouette even use a cable ? or do I hafto buy
the whole speedometer assembly ?
Another question the shifter indicater no longer shows what gear I'm in anymore is that electronic or machanicle ?
Q: "the speedometer never did this on flat level ground even if i got into
it hard ( you know for a minnivan) it would only do it if it was going
downhill"
A: that usually happens because of a bad speedo cable, or bad connection to the speed sensor.
When the speed sensor is faulty, it does not work at all.
When the speedometer is defective, well there you can get any kind of weird thing, but before replacing speedometer on instrument panel, you check speedo cable (Nr.1 Suspect), then connection to speed sensor and wiring to instrument panel.
Usually when it does this way it is the cable.
The cable is a regular wiring cable, with 3 prongs connector, worth about $10, here are other parts:
Ask to a good car mechanic to install the cable.
CAMSHAFT POSITON SENSOR. is shot
It indicates problem withspeed sensor definately.just recheck.
Sounds like the torque converterclutch is staying engaged you can unhook it.looking down at the front of your van it is a blue square plug right behind your cooling fan on the side of your transmission. hope this helps you out.
Welcome to Fixya! On the Speedometer Problem, You need to Replace the Speed Sensor, This is what is causing the Speedometer Problem. On the Tranny Problem, You need to Check the Tranny Shift Sensor, and the Board that this is Mounted on. You may actually need to have a Shift kit installed to remedy this Problem. Sounds like it is in the Computer Either way.
It is a complex problem,that can solve by a professional only.so you better to go to a autherised service center.
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HOWDY ALL! Hey fer 10 dollars, i ought to git more than" it's a complex problem" get it to a shop! I am tryin' to figure out what this might cost. My wife loves this car and i want to git it fixed for her if i can. Our old chevy pick up is not an easy ride. PLEASE, SOMEBODY GIVE ME SOME REAL ADVICE - Ol' Tom
THANK YOU! Heres just the part i want ya'll to be aware of: the speedometer never did this on flat level ground even if i got into it hard ( you know for a minnivan) it would only do it if it was going downhill and you let off quick, then it would do it, Now it does it whenever you let off the gas, does that make anybody change their mind? -Ol' Tom
PROBLEM FIXED BY AN OLD GREASE MONKEY I TALKED TO IN PERSON AND WHO GROWLED " BULL! REPLACE THE VACUUM MODULATOR" AND I DID .... NO FIXYA SOLUTIONS, BUT THERE ARE OTHER WAYS!
IT WAS THE VACUUM MODULATOR WHICH MADE THE TRANS DO FUNNY STUFF..... OK NOW AFTER FIX VACUUM MODULATOR!
VACUUM MODULATOR REPLACED AS OLD GREASE MONKEY TOLD ME TO DO AND NO MORE PROBLEM, THANX ALL BUT THIS ONE WAS NO GO ON FIXYA ........
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