A little background: The first time we ever tried the self clean a few years ago, it hung up with the "E7" error and we had to have it serviced to get the door open. They "fixed" it, or so it seemed.
The last few times the self clean has run it only manages to clean the oven floor. You can set if for 4-hours or whatever. It will heat up really hot for about 30-40 minutes, and then just quit. It won't let you open the door until the clean timer runs out. And it's not clean.
Let me add that if you are cooking at say 450 and lower the temp to 350, the oven will almost always just forget to hold at 350 and slowly cool down. You have to shut it off and leave the door open for a few minutes before turning it back on to "reset" it.