AFAIK the quarry always pump power even when it's not doing anything, so the engine souldn't explode with enough water. Just make sure the pumps and the water they draw from are chunkloaded.
Quarries act as chunkloaders, so your whole water system should be in the same chunk as your quarry, or you need to put chunkloaders if you're pumping water from other chunks.
If you do want to be absolutely sure, you can put a conductive pipe between the quarry and the engines, with a gate set to send a redstone signal only when the quarry has a job to perform.
Finally, sometime the water blocks from an infinite source glitch out and the water isn't resplenished.
There are two different solutions for that:
- always use a 3*3 body of water as an infinite source, not just a 1*3.
- the best option for pumping water is the aqueous accumulator from thermal expansion, surrounded by water blocks.