speed sensor

[david2450]

I have a 97' gst and I think the speed sensor is bad but not sure. I just got the motor rebuilt in it like two weeks ago. When I first drive the car before it gets warm it reads the speed and how many miles you drive but after it gets warmed up it stops working and will cut in and out then eventually quit working til it cools down. Also it grinds second gear everytime I shift into second but only that gear. It has a new clutch in it. Need help thanks

 

[sadc]

Don't know if you knew that your suppose to break in a new clutch.
http://www.dsmtuners.com/forums/showthread.php?t=15658

It could be your speed sensor or also your ecu

 

[the_mork]

It is not the ecu, the ecu doesn't have any direct control over the speedometer or even anything to do with speed calculation at all. All of this is handled directly by either the VSS or the TCU.

 

[david2450]

Yeah I ain't got on it yet I think it might be worse than the speed sensor though. I just drove it again and now it wasn't wanting to go into 3rd 0r 4th gear it would just slip right out of gear. An changing the gears was harder than usual. You think there might be air in the lines still doing that or a worse problem

 

[Burnett03]

As for your vss i bet your plastic gear is stripped or damaged on it, replace it.. I had the same issue.

 

[david2450]

would the vss be causing it not to go into gear or slip out of gear?

 

[the_mork]

Nope, that is clutch or transmission related, I'm inclined to guess that it is your clutch.

 

[david2450]

I got a stage 3 clutch and the clutch and motor has probably 100 miles on them now. My uncle is the one that worked on it but he is gone for a week. Do you think he might have not tightned something down or didn't bleed the clutch master cylinder good enough

 

[the_mork]

It may just need to be bled more or you could have a clutch fluid leak.

 

[david2450]

If its a clutch fluid leak how would I know or would I have to take the transmission off? Im not smart on cars I could little things on a car but not much. An where is the speed sensor at on the transmission I couldn't never find it any where.

 

[the_mork]

I don't have a manual but on these cars I would suspect that the slave cylinders are external so there is no need to drop the transmission for any sort of clutch fluid leak. You'll need to look around at the clutch lines to see if there is anything leaking.

 

[brassc2007]

it could also be that you do not have the clutch pedal adjusted right which will give you to short of a throw so the clutch is not fully dis engaging when shifting into second

 

[14spectre88]

it could also be that you do not have the clutch pedal adjusted right which will give you to short of a throw so the clutch is not fully dis engaging when shifting into second

Agreed...adjust the master cylinder rod behind the clutch pedal, all you need is a 12mm wrench to loosen the nut, then twist the rod to adjust it. I bet your uncle forgot to.

 

[david2450]

I heard that I might have bad transmission cause the car sat for 5 years or maybe even longer and now just got it running. Someone told me to drain the gear oil out and put a quart of lucas oil and the rest gear oil in to see if it helps. Think that will help? An how much gear oil does it hold an what weight? thanks

 

[david2450]

How far should the rod be tightned? He said he loosened yesterday when I talked to him. Something about it being to close to the floor but when I got in it before he loosened it, it didnt seem to bad to me

 

[brassc2007]

you want it to catch about an inch or two off of the floor

 

[delta448]

If its a clutch fluid leak how would I know or would I have to take the transmission off? Im not smart on cars I could little things on a car but not much. An where is the speed sensor at on the transmission I couldn't never find it any where.

Clutch fluid from a Master cylinder leak will come into the driver's footwell on the left side and soak the carpet. Leaks elsewhere would drip on the ground. The clutch system uses DOT brake fluid so it might confuse you if the leak is not at the Master cylinder. Place a large piece of cardboard under the car and check after a few hours for any fluid spots.

The VSS is on top of the transmission just to the right of the battery and left of the TB, kinda towards the firewall. IIRC, it's a squarish brown plug.

I don't have a manual but on these cars I would suspect that the slave cylinders are external so there is no need to drop the transmission for any sort of clutch fluid leak. You'll need to look around at the clutch lines to see if there is anything leaking.

The slave is indeed external. The MC supplies pressure via a hydraulic line to the SC, which then extends it's rod which levers the clutch fork against the TOB and pivot ball, disengaging the pressure plate from the clutch disk.

you want it to catch about an inch or two off of the floor

And remember to leave a little free play at the top of the pedal travel in order to avoid 2G pedal pump up. This is a 2G only issue since we have the pressure relief valve in the MC. The rod adjustment is critical to proper clutch operation and lifespan.

 

[jeffo]

The 2G VSS is a hall effect sensor in the top of the transmission. He may just have left it unplugged. I've also seen some that the pins were broken from someone incorrectly plugging it in. If that's not it, its probably a stripped gear, as someone else said. You need to unbolt it and pull it out to check.
keydiver