After I've started the car and begin to drive , there is a sound like I'm going over a man hole cover every time at 10 mph . It never does it again while the engine is running , even after coming to complete stops . If I turn the car off , it will do it again at precisely the same instant . I thought it was the trans. , but if I go slow and let it shift it won't do it...until I get to 10 mph .
I had a tech look at it and it stumped him . The dealer techs were stumped too ,and they of coursewanted alot of money to just find the problem . Any ideas ?

One more : Heat regulation...turn the dial , nothing until I turn it down all the way and then it eventually cools down .This happens only on the driver side .

 

im stumped right now im gonna think on it tech might have an answer........................

 

Are you tapping the brakes when it happens?
Do you use the E-brake whe you park?

 

The clunk is the ABS self test. I think it hits at 5 mph.