Whiel driving my 2004 Avalanche back from NY this weekend I noticed that the Speedometer was sitting at 60 and would move to the right as I went faster and even passed the 120 MPH . Each time I came to a stop the Speedometere would slowly move back to the left stoping at 50 and then an hour later 40 dropping each hour plus or minus til it came back to zero. Now the car seems to be working fine moving back and forth as it should. What casued it and Do I need to get it looked at?

Your instrument cluster is defective. Very common problem on newer GM cars. GM extended the warranty to 80k on most 2004 full size truck models, you are probably covered if you are within the mileage.

Reason 1001 why GM will never successfully pull out of bankruptcy and Ford will.

Abnormal, Just Because They Extended A Warranty?

Wow! That’s abnormal!

Here’s What Beefy Norm Had To Say About A 2003 Cadillac Battery Problem.

Reason 1001 why not to buy a GM product!

That is reason 1001 to ignore advice like this. It is not useful.