Coleman a/c misbehavin oddly.

At night it runs fine. I have it set to cool/auto and temp at 80. All night long it kicks and off as it should, both the fan and the compressor turn on and off together. 80 is good for me because I don't like to have cold air blowing on me all night, and first thing in the morning it is usually much cooler in here than that anyway, so I know it wasn't running ALL night.

I have not touched the thermostat. It is as it was 12 hours ago. Auto. Cool. 80.

But in the heat of the day, starting around 11 a.m., the compressor keeps kicking on and off. And it makes a groaning sound and shudders like it is dying as it shuts off. Then I hear a click in the control box and the fan comes right back on but the compressor stays off. Then another click and then the compressor kicks back on.

It has been doing this all week and is driving me bonkers. And it will do this about every 5 minutes all day long. But only during the day! At night it is operating perfectly normally, and even sounds normal, no groaning, no shuddering.

I have already tried setting the thermostat lower, like to 70, trying to keep the compressor from shutting off, and that does not change this daytime running issue one bit.

Any ideas as to why?