Sticky Tach?

[TexasTerp]

So the past couple of weeks I've noticed that the first time I drive the car each day the tach is really choppy, it sometimes gets stuck at random rpm intervals and does not rotate smoothly at all. I noticed the temp gauge having much the same problem. After driving around for a bit, it finally smooths out and is fine for the rest of the day.

Because this only occurs the first time I drive the car and smooths out somewhat quickly (10-15min of driving to school) I am guessing the problem is just a grease issue not covering the gears completely or the grease hardens a bit overnight.

Just a little location info: my car has always lived in warm climates, 1st Houston then New Orleans so it's never been through a "real" winter before. I moved up to maryland about a year and a half ago and noticed that this problem seems to only happen when it gets cold (40's and below). In warm weather I have never had an issue.

What is the best way to re-grease the gears for the tach without screwing anything up on the cluster? Also is there a particular grease that is used for it? Do y'all think it may be some other type of problem? My SI board and the rest of the cluster work perfectly fine.

[jlevie]

I have a VDO and a Motometer tach sitting on a shelf and I see no gears in either. And I know there are no gears in the temp gage. Since the tach, econometer, and temp gage are dependent on the SI board, I'd suspect it first. Well it or the fuse that supplies unswitched power to the cluster.

[87e30]

Mine was smooth until I replaced the SI batteries. I dropped solder on the SI board so I am assuming this is the culprit. I just live with it and am happy it works. It only jumps intermittently and not too often.

[TexasTerp]

I have a VDO and a Motometer tach sitting on a shelf and I see no gears in either. And I know there are no gears in the temp gage. Since the tach, econometer, and temp gage are dependent on the SI board, I'd suspect it first. Well it or the fuse that supplies unswitched power to the cluster.

Temp gauge I can understand. and that only sticks to the bottom when its cold.

I don't understand how the tach works, there has to be some type of gear or motor that drives its rotation. It can't be the SI board since it only happens the first time I drive and is perfectly fine after that, and same with the fuses, if the fuse was blown it wouldn't work at all let alone start sticky and smooth completely out later. Plus it's weather dependent, warm temps = no prob, cold = problem. I've never removed the cluster from the car and haven't ever had any work done it.

[nando]

there are no gears in the tach. it takes a signal from the ECU and uses a tiny electric motor to turn the needle. The other gauges all work the same, the only thing that is mechanical is the odometer but that is still driven by an electric motor.

also, mine has done this many times when it's really cold out (well below freezing). i wouldn't worry about it.

[TexasTerp]

Thanks so much, I figured that if there weren't gears then it was some small motor. Good to hear about someone else experiencing this. Now I can forget about it and move on to the other 100 things I need to do to the car! lol


/thread

[e30polak]

Stop masturbating in your car, and maybe your tach wont be so sticky. :p