Small oil leak.

[Smutterworth]

Hi guys. I found a small oil leak under the Z. I can't get under there to check it out so these are some photos I took by sliding my phone under on a board.
What part is this? It's about middle of the car left to right, and roughly inline with the back of the front wheels. It looks like engine oil rather than tranny fluid. I'm hoping it's just a loose bolt or failing gasket and nothing is cracked. Is it likely coming from this bolt or running down from further up? Thanks in advance.

 

[KrackaC8]

Coolant runs into it... Looks like a fluid cooler. Wouldn't be the engine oil cooler since that's oil-to-air on the Z. Could you zoom out a bit? Does the AT have a dual cooler setup?

I suspect it could actually be used as a fluid warmer. Part 31069N, perhaps?

 

[Smutterworth]

Coolant runs into it... Looks like a fluid cooler. Wouldn't be the engine oil cooler since that's oil-to-air on the Z. Could you zoom out a bit? Does the AT have a dual cooler setup?

I suspect it could actually be used as a fluid warmer. Part 31069N, perhaps?

This is as much as I can zoom out. Stupid low car, lol. It definitely looks like that thing right below the bell housing in your diagram. Are they water or oil lines going to it? It does seem to have small fins around the outside, but are they big enough to offer usable cooling? I've only had this car for a month so I'm totally new to this thing.

 

[KrackaC8]

This is as much as I can zoom out. Stupid low car, lol. It definitely looks like that thing right below the bell housing in your diagram. Are they water or oil lines going to it? It does seem to have small fins around the outside, but are they big enough to offer usable cooling? I've only had this car for a month so I'm totally new to this thing.

With that being a fluid-to-water cooler, it wouldn't need to have fins on the outside to dissipate heat as engine coolant runs through it (similar to our air-to-water intercoolers). It looks like a pretty standard oil-to-water brick cooler. My Jeeps have them, my Corvettes had them, etc. The only difference here is that instead of engine oil, Nissan is using it for transmission fluid. I'm theorizing to quickly bring the fluid to temp w/warm engine coolant, while the front-mounted fluid-to-air cooler is used to to keep temps in check on the high side.

Back to your pictures, the engine coolant is plumbed in there through those rubber hoses, while the transmission fluid enters & exits from ports on the underside of the brick.

These are just my assumptions & theories, with it leaking fluid you absolutely need to get it into the dealership for a warranty repair (likely either a loose bolt or a pinched rubber seal). A similar sight isn't unheard of in the Jeep world either (but typically due to age/miles, yours could just be an assembly error), the important thing to know is that it's usually an easy repair and doesn't lead to a critical failure, as long as its addressed timely.

 

[FSUZ33]

Most call it a cooler, but one Nissan parts website calls it a cooler/warmer.

https://www.z1motorsports.com/oil-c...ssan-transmission-oil-cooler-9at-p-46603.html

If the fluid is coming from somewhere on that cooler, housing has a crack or pinhole, or it’s leaking at the connections on the other side, its ATF and you should be able to smell the difference. Or taste. Engine oil tastes like green Skittles and ATF is more like a blue raspberry Jolly Rancher. Prove me wrong. Neither leaking oil nor ATF is good, but I feel like the least bad in your case is if that ATF cooler was slowly weeping from somewhere.

I say dealership/mechanic.