My 2004 Cavalier's speedometer doesn't work once the car gets warm. As soon as it stops working you can smell antifreeze. Are the two problems related? The speedometer either gets stuck in one place or continues to climb over 100 mph even when you are going 10. You can reset the speedometer once the car cools off by playing with the ignition before starting. Anybody have any ideas?

My 2004 Cavalier's speedometer doesn't work once the car gets warm. As soon as it stops working you can smell antifreeze. Are the two problems related? The speedometer either gets stuck in one place or continues to climb over 100 mph even when you are going 10. You can reset the speedometer once the car cools off by playing with the ignition before starting. Anybody have any ideas?

That is a strange combination.
I would find the coolant leak fix it.
Check where the coolant leak is and make sure it is not getting into the wiring.
The PCM and speed sensor are both right rear engine compartment.
Good luck and let us know how it goes.

Thanks for the reply!

Do you think it would cost a lot to get fixed?

Thanks for the reply!

Do you think it would cost a lot to get fixed?

I would check it out first.
Looking is free. But the fixing may cost.:lol:

I never did figure out this problem. Now that warmer weather is here it doesn't do it anymore. I never did have an antifreeze leak either. It was a mystery I have never figured out.