944 Speedometer Problem

Stanton Horne · 06-07-2002, 03:05 PM

Speedometer in my 1986 944 jumps to 100 mph when I turn the key on. Also, the odometer is stuck with trip mileage stuck at 799.9. Anybody got any ideas of what the problem could be?

AFJuvat · 06-07-2002, 04:19 PM

Stuck odometer probably points to stripped out gears - never reset your trip odometer while the car is moving.

The speedometer jumping points to some sort of electrical problem. I would check your sender on the transmission, followed by the electrical contacts on the instrument cluster.

AFJuvat

shlim · 06-11-2002, 10:08 PM

Yeah, I would second what AFJuvat just mentioned. I had a similar problem, except that my speedo would jump from 40mph to 70mph in a split second and back. (how's that for a quick 40-70mph acceleration timing !). Turns out that the connector to the sensor at the gearbox was cracked and loose. Once that was tight, everything was fine.

Odometer dying off seems like a common problem, just had mine replaced (with a used speedo), it's good to know what mileage I'm doing again.

shlim
85.5 944

slevy951 · 06-12-2002, 11:37 AM

Quote:

Originally posted by Stanton Horne
Speedometer in my 1986 944 jumps to 100 mph when I turn the key on. Also, the odometer is stuck with trip mileage stuck at 799.9. Anybody got any ideas of what the problem could be?

Is this odometer stuck also or just the trip? If it's both, you have a bad gear. See link below........

dogslovetrucks · 06-12-2002, 01:18 PM

hey slevy951- what if it's not both? My trip and odo work fine but after hitting the reset while moving, the 1st dig on the odo rolled over to "8", making my car have 810000 miles on it.

slevy951 · 06-13-2002, 04:20 AM

Quote:

Originally posted by dogslovetrucks
hey slevy951- what if it's not both? My trip and odo work fine but after hitting the reset while moving, the 1st dig on the odo rolled over to "8", making my car have 810000 miles on it.

It'll have to be taken apart and reset to correct mileage.

Brian J · Brian J's Garage

Quote:

Originally posted by shlim

Odometer dying off seems like a common problem, just had mine replaced (with a used speedo), it's good to know what mileage I'm doing again.

shlim
85.5 944

I thought that what police radar guns were for!

Brian

wmcneil · 07-05-2002, 10:10 AM

the problem with the odo gear is that it gets soft and falls apart. the shock of the solenoid hitting can aggrevate it, but it is not the cause of the problem.
there is a mechanism that disconnects the the trip meter from the stepping motor when the solenoid is engaged, so resetting it while the car is moving is not really the problem.