For about the past week, my starter has been turning very slowly sometimes, and it will just barely start the car. Other times, it turns fast as it should. I have a brand new battery and the alternator is charging at 13 - 14 volts. If I sit there and start my car and turn it off over and over, the starter will work just fine about half the time, and turn the motor very slowly the other half.

I searched for starter problems, and I am led to believe it's either a grounding problem or my starter is going bad.

If it's a grounding problem:

Why did it start happening all of a sudden?

Why does it work just fine half the time?

How do I fix it?

If it's the starter:

How do I know for sure it's the starter?

Could it possibly be something other than these two possibilities?

Thanks.

 

I like to keep things simple first. More than likely it is just an intermittent connection somewhere. Remove all lines going to the starter and use emery paper to remove corrosion and reinstall. Do the same to the engine ground line. Don't forget to cleanup the battery terminals as well. I had a starter once that the case had loosened off intermittently jamming up, insure the case (part over the electric motor) is tight to the rest of the starter frame.

 

I ran a 4 guage ground wire from the battery to the frame in addition to the one that was already there. That fixed it. I'm still going to run another big one to the motor and the exhaust. Thanks.