Redstone engine bug that was fixed in 6.1.3 seems to be back now that I upgraded to 6.1.4.

Type: Don't know the categories, medium size bug?
Description: If I set an engine by itself, it doesn't animate but the colors change until it's at full power. If I attach a redstone engine to a pump or extraction pipe, it stays(or reverts back to if already on) blue without powering device.

Mods: Too many to list concisely so I'll post a link(ignore version numbers, I've updated many of these since creating the pastebin, also added Thaumcraft and Witchery): http://pastebin.com/6YuxmiyC
Buildcraft: 6.1.4
Forge: 10.13.2.1232

So if it isn't a bug please close this issue.

How is it not a bug that newly placed redstone engines only power up to full when not attached to pipes or machines?

Pumps don't currently work with redstone engines. About pipes... they seemed to work fine with me.

It is an intentional change, as redstone engines provide too much free power... and i don't want to do whitelists of allowed Tile Entities, so I just blocked all of them. (Unless you're a non-Power pipe)

Okay, so from 6.1.4 onward, Pumps require a Sterling Engine or higher to work, and redstone engines will only supply power to extraction pipes? I just want to make sure I understand the change fully so I don't report Works As Intended as bugs in future.

I'll try other pipes, but wooden fluid extraction pipes cause the redstone engine to stay blue as if attached to a pump. I'll check other types of extraction pipes in case it's related to the fluid container the pipe is pulling from/to(in my case, it was from an OpenBlocks fluid cube to an IC2 Geothermal generator, but the setup worked normally until I turned off the redstone engine and turned it back on again after the update.

EDIT: regarding fluid pipes, the engine attached to the fluid extraction pipe probably remained blue because it couldn't move further lava into the geothermal engine. Further tests show this to be a fluke. Pipes seem to work fine now, so I'll assume that part of the issue was just lag. Will keep testing pumps and redstone engines with different fluids.

Thanks for the prompt reply, and for all your work on Buildcraft.

Since 6.1.2 onward, and redstone engines supply power to all non-power pipes which require power (extraction pipes, stripes pipes, obsidian pipes...). Other than that, you are correct.