What's on the back of engine, above oil pan? (Wet!)

@PriusCamper your wish came true, unfortunately.

I'm suddenly seeing a pool of wet on the garage floor after each of the last couple of drives. Not oily. No real smell.

I need to find what this is and solve it. We leave on a 4000 mile driving trip in one week.

My main questions:

• what are the (wet) bolts/devices on the back-right side of the engine, above the oil pan, and below-right of exhaust???
• Could the black bolt in photos be loose?! (I've not attempted to change anything.)

Jacked up car. Looking at the back side of the engine I see some wet components, particularly a black bolt, and another wet one above it that's hard to see.

In the photos, "down" is toward the front of the car. I am lying beneath the oil pan, whose attachment bolts are visible in the final photo.

The black bolt "under" the metal plate (and clip for some wire) was quite wet. A lighter bolt above it was dirty/wet. Then in the first two photos you can see a black bolt or cap or ??? that's also glossy/wet.

I'll search for appropriate engine diagrams...

THANK YOU! What an amazing community

 

Hybrid Pitstop replaced my entire engine (with a Gold 2015 rebuilt from ground up) only 30k miles ago.

Is that a likely gasket leak so quickly?

 

Good question. And THANK YOU for digging in with me on this!

Here's a new picture from the side w/ the right front wheel off.
100% of the wettish area is around the two connectors and the black bolt (which is behind (left of) and a bit below the upper connector.. Above these, it's dry dry dry.

I do not know if this helps w/ identification: I notice that the upper connector is at right angle to the back of the engine. The lower one is tipped by 10-20 degrees or something like that.



I am also wondering... could this simply be condensation from the A/C unit? Doesn't really sound right to me... grasping at straws I admit!

 

Interesting. From the link below (sub-figures "C" and "D"), looks like those are "Plug, w/ Taper Head Screw" -- just a bolt that does nothing?! Perhaps they have some kind of manufacturing purpose. (NOTE: my engine is 2015 now... I looked it up. Those parts haven't changed.)

https://www.amayama.com/en/genuine-catalogs/epc/toyota-usa/prius/zvw30/13503/engine/1105?frame_no=JTDKN3DUXB1414344

 

That is what I am starting to think.

My question about that: *where* does condensate drain? I thought it was in the front next to radiator/fans.

 

I think the engine wetness/shiny is separate from the pool of watery liquid on the concrete. Gonna treat it that way at least.

 

For now: treating everything as minor. Did a bit of tightening, cleaned MAF sensor etc, Going to beat up the car this week, and hopefully it'll be solid on this next trip.

One thing learned and an improvement made:

• For my new fancy head unit, I extended the CANbus from the OBD2 connector to the radio area...
• Worked great, for a while. Then one of the connectors went wonky.
• Cars do NOT like an intermittent CANbus wire!!! Got quite the error display on the dash, and a zillion DTC's
• Asked my ASE Mechanic friend how he connects extra wires. I followed his advice, which concluded with "Pete, I've never had ANY failures using this method. Ever.

It cost a few pennies for a new crimp tool and some parts, but all is much more solid now. My new way to connect extra wires almost anywhere:

• NON-insulated butt connectors (metal tubes. I got a set with AWG 24-8 sizes) -- makes it simple to test AFTER making the connection.
• Appropriate crimp tool (I bought the iCrimp Ratcheting Crimping Tool Set, with replaceable jaws. Handles AWG 20-2)
• Good heat shrink tubing (I got Eventronic 4:1 ratio heat shrink, which includes internal adhesive. Makes a waterproof, tough coating. Very happily using on lots of things now )
• (I already own a very nice heat gun, used for an incredible variety of things including 10 minute freezer defrosts LOL. Metabo HPT Variable temp gun+kit 100-1200F. $85 when I got it.)