98 gst speedometer problems

[Robbyd]

I have a 98 gst, I just purchased it yesterday. The speedometer doesn't work alone with the mileage, wondering what all would cause this? I was told it's the speed sensor which would make sense, but I was also told by my mechanic who's a transmission specialist that if the speed censor was bad it would throw a code. Would it throw a code if the teeth on the censor and messed up.

Any help would be appreciated, thank you!

 

[GofaST4life]

The VSS (vehicle Speed Sensor) is located on the inside of the rear tranny/engine mount. Can be a pain to get too if you have big hands. I removed the battery, tray, Upper IC piping to make things much easier.

Using a 10mm socket, carefully remove the sensor, MAKING sure not to let the gear drop. Be patient.

Mine was in operable when I purchased my car. It only threw a code after I reset the ECU. So yes, it can throw a code, but may not all the time if someone had already cleared it.

Change your VSS and drive happy.

Be sure to purchase the correct VSS though. There are some differences between 95/96 and the later models. I believe its with the gear teeth and/or length.

 

[Robbyd]

Alright sounds good thank you, hope it's the problem. And other common issues that would cause this?

 

[Firsts tuner]

I had the same problem on my GST. I had to remove the rear mount to get to the bolt holding the VSS but mines an automatic. Mine didnt throw a code. Be careful of the vacum nipple on the BOV. It will break off pretty easy. Ask me how I know. I found a replacement in a late galant with a 4g64 auto. 2 bucks at pull a part.

 

[Total Eclipse]

It wil only throw a code if the sensor's electrical part is faulty. If the teeth are stripped/not aligned/gone, then it will not throw a codes, as the sensor itself is good, just not being turned (as if you were parked).

 

[spyderdrifter]

And other common issues that would cause this?

Only other issues that could even come close to causing this issue would be a broken, defective, highly corroded wire somewhere along the system, or the gauge itself went out. But those are unlikely. Like mentioned, best bet is the VSS.

 

[miguelmcv]

I have a 98 gst, I just purchased it yesterday. The speedometer doesn't work alone with the mileage, wondering what all would cause this? I was told it's the speed sensor which would make sense, but I was also told by my mechanic who's a transmission specialist that if the speed censor was bad it would throw a code. Would it throw a code if the teeth on the censor and messed up.

Any help would be appreciated, thank you!

Wait a minute, am I miss undestanding your post or all the guys are?.

Is the speedometer completely dead?, or it just shows the speed you are running but the mileage doesn't stores.

If the speedometer is completely dead then you have to test if your SSV is good, It can be your SSV as people have stated before, or it could be your speedometer it self.

But, if it shows the speed you are running but doesn't stores the mileage, then your SSV is good and you have a bad tachrometer, you need to change your cluster or the speedometer it self, but your SSV is working good.

Just specify if it is completely dead or if it shows the speed you are running, so we can understand better your post.

 

[m1nd64m3]

Sounds like a speed sensor problem, and when it stops working so will the odometer and tripometer along with your speed. Make sure you have the correct gear since the auto gear has a longer shaft than the manual. It's easy to replace, just unbolt the 10mm bolt holding it in place and pop it up. There is a clip holding the shaft into the sensor.

 

[Robbyd]

Spelling error, you just misunderstood it. I ment the speedometer is completely dead, along with the odometer. But yea it's the problem it threw a code. Also was looking at my throttle body and I'm missing a vaccume hose on the throttle body, I don't remember which one it is, it's the first one. Wondering if anyone knows what that lines for, I don't know if I'm getting a bad vaccume cause of it.

Thank you everyone for your help.

 

[KewlWinter]

Another very uncommon but possible cause is where the cluster has been pulled and either reinstalled or replaced and the surfaces on the back of the cluster that mate to the dash connectors are crudded or it wasnt seated properly. I saw this once on a friends car he just purchased and turned out they replaced the cluster with another that had lower mileage. Can you say Carfax?

 

[Robbyd]

Also have an oil leak, from looks to be like some sort of plug or adjustment screw. It's right on the bottom of the thing that holds the oil filter on. Wondering if they have some sort of gasket on it, what it is. Cause I need to fix the leak asap, don't like oil on my driveway haha

 

[Deadpool25]

I have a GS with the same problem Speedometer dont work or the odometer so let me know what happens when u replace it

 

[nmg72]

You purchased the car while it had a bad speedo and was leaking???

 

[Robbyd]

Haha yes I did, cause I knew speed sensor isn't a big deal, and he said it didn't leak at all just had oil on it when the dipstick shot out. Doesn't leak a lot tho, will fix it. Stupid people and there homemade oil pan gaskets...

 

[CDSchlis]

Hey guys,

I'm having a similar issue, only I'm not sure what's causing it. It could be the VSS, but I'm here because I can't get a definitive answer from the experienced people I've asked locally. This afternoon I did a pull, got up to about 6k in 3rd gear and where it would normally shift, the car bucked twice, violently, I instantly let off on the gas thinking the trans slipped, and it shifted down fine and drove fine from there on out today. What I didn't notice until about a 1/2 mile down the road was that the speedometer was moving completely erratically unless I was at about 50% throttle, and from time to time while slowing down. Any ideas? It's never done anything like that.

99 Eclipse GST (Auto), 3" Apexi exhaust, SAFC II piggyback, blow off, upgraded fuel pump.