I've got an 07 Fit (Sport) with about 160k mi.

Lately it seems to struggle a little bit... It feels like the car is stuttering (for lack of a better description). Originally I thought it might be engine trouble but now I'm thinking this is a power problem.

The stuttering gets worse when I run the AC, hot or cold. In the last week or so I also noticed that my tail lights seem to have trouble getting power. The car also turned off (once) when I was at a stoplight. The car gets worse if it is very hot or cold out.

The most recent development/oddity is that when I checked my oil I noticed the plastic cap to the positive on the battery seemed all crushed up. My first thought was that it got smashed by the hood but then I realized that the plastic had started to melt. The plastic did not liquefy at any point but it definitely had heat deformation.

I am going to take the car in soon, but I was wondering if this had happened to any of you or if you know what it might be? It's a difficult problem to describe because all I can say is the car seems like its developed a stutter in terms of describing how it drives/what the problem is.

 

Due to the fact that stuttering can be result of ignition coils failure, I would check for this as well. The battery terminal can melt if there is an electrical arching under it. There are multiple wring connections and alternator fuse link under this plastic cap.