Speedometer not working when car is hot
Thread Starter
Instructor
Joined: Jun 2004
Posts: 239
Likes: 0
From: Barnegat NJ
Speedometer not working when car is hot
Guys,
Anyone experience this problem. After i drive my 88 4+3 vette for more than about 15 minutes the speedometer stops working, the overdrive kicks out and the check engine light goes on. I replaced the speed sensor and still have the same issue.
Anyone experience this problem. After i drive my 88 4+3 vette for more than about 15 minutes the speedometer stops working, the overdrive kicks out and the check engine light goes on. I replaced the speed sensor and still have the same issue.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,009
From: Texas
Otherwise, the next step is to ensure the wiring connections are clean/tight, both at the VSS and at the ECM.
If you have a software to datalog with, you can watch the speed output from the ECM and see if it matches what your speedo is doing. If it does, then you know the feed to the cluster is good. If it does not match, then you may have an issue with the wiring to the cluster. Since the OD stops working and you get an SES light, the cluster and wiring to the cluster is probably fine.
What code is stored? If it's a VSS code, refer to my first two sentences above.
Team Owner
Joined: Sep 2003
Posts: 25,398
Likes: 2,742
If the clip has failed on the drive gear when the trans gets to operating temperature the drive/driven could bind and the VSS signal goes to -0-! I've got to admit it's a "stretch" but it is an explanation and you mention the failure is somewhat consistent. The VSS branding is another possibility and you need to make sure you've got a VSS for the 42 tooth(I believe) gear that should be in your trans.
I'd do the codes first and then a physical check of drive/driven and clip condition.
I'd do the codes first and then a physical check of drive/driven and clip condition.
