Engine liquids
The engine has several places where there are 'vent lines'(for lack of a better expression) which vent liquids into the engine compartment. One of these, for example, is for the heat exchanger and exits near the 'radiator cap'. Another vents off the aft end of the engine near the mixing elbow (on a 3GM30F, I think this is a vent for salt water - without the line the salt water drips on the engine and gets it rusty). I've added another vent hose for bleeding air out of the antifreeze line just above the thermostat. Each of these hoses I put into a plastic bottle (Seattle 'Talking Rain' water bottle). The lable is removed which provides a clear view of the liquid level and the small opening on top helps to prevent the hose from poping out.Use #2 for these plastic bottles is to wrap them around hoses where the hoses rub against anything to prevent chafe. I cut the top and bottom of the bottle off then split the side. This provides a nice piece of plastic for wrapping around the hoses. Use plastic wire-ties to hold them in place. On aircraft the mechanics use silicone sealant between things that rub against each other and that could be done also. A little sealant on the hose before puting on the plastic will prevent it from sliding up or down.