Hi,

I have a 1997 Blazer, 4wd and I have a problem I just noticed last week. I was driving and noticed that my tachometer was jumping around sporadically. It went away quickly and I didn't see it happen again until today. So today I watched and noticed that when in the over drive gear, the tachometer starts to jump around 2000rpms and 60mph. If I'm in any lower gear, it does not jump at all. I'm not sure what would be causing this. I checked the fluid and it seemed fine. It threw a code but I haven't been able to check it yet to see what it was. I will try to do that tomorrow or this weekend. Any help would be appreciated.

Thanks,
Adam

 

Sorry for the late response. Must have missed this post somehow. Post notifications have been erratic for the past 5-6 months. Anyway, sounds like the torque converter is shuddering, causing the jump in the tach. We will need to know that code to work further.