Quote Originally Posted by chevyman View Post
Something I have seen at my shop is there is a gear inside the transmission that can get damaged and cause the speed sensor to not read very well... The transmission can become contaminated with antifreeze from a failed transmission cooler.... Check to see if you have trans fluid in your coolant reservoir, if you do you may have this problem... Also I found this guy put a video on it.

The guy in the vid you posted was working on a 2007 and says this same issue is across all Aveo, both gen 1 and gen 2. That's the first time I've seen that posted - up until now it's only been reported for the gen 2, and in particular the 2009. The radiator is a different part for gen1 and gen 2, and everything I've read to date indicates that the systemic problem with the radiator was with the newer part only. Not saying it can't happen on the gen 1, only that it hasn't shown up on this forum, or any other online sites either (that I'm aware of).

However, very few pros post about their repair history on these forums, and I'm very interested in what you have to say. So at your shop, have you seen multiple gen 1 Aveos with the coolant/tranny fluid mixing in the radiator? Or has it been almost all gen 2 Aveos where you've seen this issue?