Oil cooler sprung a leak

While looking underneath my truck with a light I seemed to have noticed a small leak around the factory oil cooler. At first I fig it was running down from the top side from elsewhere but after wiping it with my finger it had a greenish color to it. After further inspection the outside appears to have a small amount of coolant on it. I know these have o rings but I don’t think I should be seeing coolant, oil seepage maybe but def not coolant.
Would this be just a o ring replacement or does anyone think the cooler itself is cracked or something??
Thanks

 

There's more than one o-ring/seal on these oil coolers-at least there's more than one on mine (but you've got a, what, 6 cyl? whereas mine's a 4 banger so coolers probably not same......IIRC mine has a total of three) and the oil cooler seals are notorious for being the source of oil leaks on Tacomas. But-coolant? (scratches head) can't think of any way the oil cooler could be source of engine coolant leak-How's the coolant level in your radiator and overflow been doing?
FWIW I bought the wrong outer seal for my oil cooler (OEM, from Toyota) (it's a molded o-ring, shaped somewhat like the number "8".... goes between oil cooler and engine block) so I have one I can't use if you want it. The oil cooler is also (sometimes) referred to as the "oil filter adapter housing".... I'll track down the part number (tomorrow) when I get home from work .

 

Yea mines the 3.4 I will check it again to see if I notice any green. I know the coolant runs through it some way internally. Like I say it was just a tiny amount. Coolant level is still fine. It has at least 2 o rings I know. A large one and a smaller one around the large center bolt.

 

I realize it’s hard to see but along the back edge of the cooler it’s wet and has a green color to it. Not much but I didn’t know if coolant could actually seep out of these things or if I’m crazy.

 

they are a pretty robust unit. I would suspect a coolant line first. These things aren't cheap to replace either.

 

Coolant lines are bone dry, i had leaky valve cover gaskets that i replaced so alot of oil was seeping down that side, at first i fig it was just still wet from old oil that ran down.. it was the green color that threw me off.. im just gonna keep a eye on it, its not a issue right now just didnt know if it was a bad o ring or the actual unit was leaking.

 

the o rings only seal the oil and not the coolant.

 

keep us posted.......(curious to see what conclusion, if any).

I never got to look up the part number because 'backup' laptop died- again- (I might have 'accidentally' 'contributed' to the final demise....bleeping computer.....)

 

As of now I’m just keeping a eye on it. I don’t really drive my truck much during the week anymore, I have a company vehicle for work. But it’s def on the list to things to repair. It hasn’t gotten any worse but anytime I see coolant where it doesn’t belong I get concerned lol.

 

Just got a quote from gunny, about $5 for both gaskets which I will get. And a FYI new oil cooler runs $601 from camelback. Those little things are expensive!