Infill keeps "shoveling", but perimeters are fine While printing PET-G (@ 220&nbsp;&deg;C nozzle and over 58&nbsp;&deg;C bed temperature), the outlines always print fine but the infill keeps shoveling. Could I be printing too hot or too cold? I am using a 0.8 mm nozzle. 

Shoveling is when the plastic is over extruding to the point at which it starts piling up in the path of the nozzle, usually resulting in an uneven surface. Visually, it manifests like a snow plow shoveling snow. I tried adding an image, but, the filament is black so that turned out to be a difficult task.

This reason why this is a problem is because the nozzle hits those peaks while printing, which seems to be causing the print to detach from the bed. I've also noticed the print curling up at the edges, but I think that's a separate problem.

I am printing at 3000&nbsp;mm/min. The outline, and the infill is 80&nbsp;% of that. The layer height is 0.6&nbsp;mm
Normally, what you're calling shoveling is caused by having the bed too high - when you deposit enough material for a space that should be the nominal layer height high, but significantly less volume is available, it has nowhere to go but up around the edges of the nozzle.

However, in your case your temperatures are also seriously wrong for PETG. The normal recommended range of nozzle temperature for PETG is 230-250&nbsp;°C, and in my experience, you need the full 250&nbsp;°C to have any hope of printing fast. At 220&nbsp;°C I'm really surprised you're not having problems with underextrusion instead.

The bed temperature is likely even more important. Minimum bed temperature for PETG is 80&nbsp;°C. If the material is hitting a 58&nbsp;°C bed as it comes out, it's likely to cool way too fast. This may lead to what you call shoveling (especially if you see both pits and ridges rather than just ridges), but even if not, it's going to prevent the material from bonding to previously laid down lines, so that your print will end up more brittle than PLA.

One additional detail I initially missed involves your 0.8&nbsp;mm nozzle. It might be hard for the hotend to keep up with properly melting that much PETG at normal print speeds. As noted in the comments, a 50&nbsp;mm/s linear extrusion rate with an 0.8&nbsp;mm nozzle is equivalent, in volumetric extrusion rate, to a 200&nbsp;mm/s linear extrusion rate with a typical 0.4&nbsp;mm nozzle, which would be extremely fast for PETG. It's unlikely that any hotend except a "volcano" or similar (with extended melt zone length) could keep up with raising that much material to 250&nbsp;°C that quickly.