Hello. I just noticed this greenish leak near my engine. The car is at 158k miles. I assume it's a coolant leak? I checked the coolant level and it's above the minimum line, although very slightly. I never got any lights or warnings regarding engine overheating. How urgent would you say this is? The following photos show the leak and the coolant level in the tank while the engine is cold.

An interesting thing is that I posted this same question to Reddit and somebody suggested that might actually be some copper/metal rod that corroded because leaked coolant is not supposed to coagulate like that and just burn off instead. I tried to find some under-the-hood photos of this car to see whether there is any part like this over there but I wasn't successful. What do you think?

 

My '07 RDX had something like this happen around 120k miles...I had always had it dealer serviced but nobody ever said anything about corrosion or etc. Anyway, the coolant reservoir catastrophically failed out of the blue and became contaminated with some other engine fluid...I want to say it all leaked out all over my driveway IIRC. I forget what it was maybe transmission (?) fluid but dealer replaced the whole part...it was not cheap fix. Like $1200 or something. I hope yours was caught early enough not to cause you that kind of pain! Good luck.

 

Is the coolant level staying consistent? If it's not slowly getting lower, then it's probably not that.