Unplug EGR Valve

If you are losing coolant it is at an advanced stage. Sealant might work for three months if you are very lucky.

The insidious thing about sealant is it seems like a miracle at first and people get false confidence. A couple of months later they repeat because the rattle returns. Pretty soon it's junk the engine or car. The car because the radiator and heater core are messed up.

Bottom line, really save for another car in three months regardless of how great the sealer seems.

 

but this was a trail of fluid for a long stretch of gravel road. it was dark enough and wide enough that I thought my coolant was empty but when I looked it was fine. even checked the oil and its fine.

 

What color is it? If it's dark, dark what? Brown? like engine oil? Red, like from the transmission?
The coolants don't get a dark color.

 

Coolant leakage can occur due to damaged hoses or too high engine temperature, when it will be released through the relief valve on the radiator. What was the engine temperature at the time?
Do you use any diagnostic tools?