It could be a bad connection from the dash to the gauge cluster. That's what caused my gauges to go nuts. Started occasionally, then increased in frequency before I finally pulled the dash to clean and tweak the connections. Hasn't happened since and that was about 4 years ago. The next time it happens, push hard on your gauge cluster and see if that has any effect on your gauges. Is it does, this is likely your problem. It's a 15 minute fix to pull the cluster and put back together.