Looks like a headgasket issue...
 

...on the Tribeca.

Wife came home and the car was "making a funny noise". I came out and heard a hissing noise. That's not good. Saw a liquid pooling under the car. That's not good. I thought I smelled coolant. Ugh. Then I dipped my finger in the liquid and it was oily. WTF? Popped the hood. Overflow tank looked normal for level. Checked the dipstick. Definitely lost a little oil. Level was halfway between L and H. Looked under the car and it looked like the leak was coming from near the oil filter. Popped off the cover and looked up there with my scope. The oil filter and sandwich style oil cooler looked clean. I couldn't see where the leak was. Temp gauge had definitely gone above midway but CEL was off. Checked the coolant in the overflow tank and it looks like watered down Cola.

I am assuming the headgasket. But why didn't the overflow tank overflow? And why did I get the hissing from under the engine? Could the oil cooler have sprung a leak? Could something worse than a headgasket have failed? I heard no other unusual noises when the engine was running nor did I see anything on the dipstick other than honey colored oil.

Re: Looks like a headgasket issue...
 

hopefully your dark coolant and the leak are unrelated. i have seen the small hoses that go to the oil coolers leak, sometimes only when under pressure. it creates a clean spot because the coolant cleans gunk off your engine and makes it oily. it would be unusual to have an internal and external head gasket leak if you had no previous signs of trouble. overflow reservoirs don't need to overflow if the coolant has another place to go, or you are not that hot.

you can test for a head gasket internal leak with this for $30 or less.
an external leak you will just have to run it and watch for leaks.
how does the fluid in the radiator look?

Re: Looks like a headgasket issue...
 

I didn't extract coolant from the radiator but i did wipe the inside of the neck and it was slippery.

Re: Looks like a headgasket issue...
 

coolant usually feels slippery. oil and water don't mix well so oil will usually be separated from the coolant to some degree. once it gets mixed it looks like a chocolate milkshake.

Re: Looks like a headgasket issue...
 

What do you have coming out the exhaust...any white smoke or sweet smell of coolant? I've found putting the overflow hose in a container of water will show bubbles with an internal leak since you can leave the cap on and system

Re: Looks like a headgasket issue...
 

Didn't check the exhaust but I don't recall anything unusual. It is at my mechanic's place now.

Re: Looks like a headgasket issue...
 

It turned out that it was only a burst hose. The slippery feel was not oil after all. Sometimes we get lucky. The money ended up going toward a new clutch for the Acura.