engine oil leak

Hi all,
During 2 engine oil changes ago (at 51K miles) i noticed a drop of oil residue on the backside of the engine block above the oil pan. It is dark brown and feels like engine oil. I wiped it clean for further observation. During the last oil change 1 week ago at 56K miles, the same spot is again wet with oil. See pictures #1 and #2.

I wiped it clean and drove for 4 days then raised the car and checked again. Same thing-a drop of engine oil is hanging on the same spot, see picture #3. This leads me to think there is an oil leak in that area. I don't know where the leak is from, can someone help to identify potential sources? The camera is facing up from under the car. BTW there is oil residue on the other side of the "big metal block" as well.

During all this time the leak has never accumulated enough to leave spots on pavement. I did all oil changes on my own. I have not dripped oil when filling on top.

The location of the oil leak is above oil filter and oil pan, so it couldn't come from either places. Facing foward with the front of the car, the oil residue is on passenger side, directly above the backend of oil pan, on the backside of the engine to the right of the exhaust manifold heat shield which is visible in picture #1. When looking up from under the car directly past the oil spot, the windshield wiper cowel is in the way so it's not possible to spot the leak from above. Can someone identify the source of the leak based on the pictures? Is this serious and do I need to take it to the dealer?

A second question: in the last picture (#4), does it look like a cracked engine block? I took this picture in the vincinity of the oil leak while inspecting with a reflecting mirror. The "cracked" location is below the aforementioned oil leak.

My car is a 07 with 57K miles and always used Mobile 1 5W30 with Toyota filter every 5K miles. I bought the car new and it has never been in any kind of collision. Thanks for any insights anyone can provide!

 

Thanks for the feedback Hobbit and Patrick. The thing is that the drop of oil would reappear every time after I wiped it clean, so this appears to indicate it's coming from the engine. While doing oil changes i have never spilled from the top out of the funnel. I will remove the cowl this weekend to have a look from the top.

My car has 57K miles - still within the 60K power train warranty, if the leak is from the engine (valve cover, etc) would it be covered under the warranty?

 

The powertrain warranty does cover engine gaskets and seals.

I took the cowl off today but it's still hard to see the back of the engine when looking straight down from the top as the valve cover lip and exhaust manifold heat shield are in the way. But I was able to feel around the valve cover and there was no oil around the gasket.

Then i went under the car and it appears oil was leaking from several spots: upper oil pan gasket was wet at the location indicated by the lower red circle in the diagram and a spot near the #1 cylinder exhaust (upper red circle). THe middle red circle is where the surface crazing is, and that area is also wet.

I felt around the timing chain cover, there doesn't appear to have any leaks around the cover gasket.

Has anyone else noticed oil in these areas? Patrick you mentioned if the leak is minor then it's not serious - but will it get worse? Should I take it to the dealer? Is it a big job to fix this? I will attach some pictures soon. Thanks.

 

OK on more careful inspection, the leak came from 2 places: 1. upper oil pan gasket like i said before, 2. timing chain cover near the exhaust manifold.

So how long a job is this at the dealer, to change the 2 gaskets, if these need to be fixed? Is there supposed to be oil inside the timing chain cover? Thanks.

The picture shows the leak from the upper oil pan seal. I can't get a picture of the timing leak from timing chain cover.

 

Good suggestions here. the valve cover gasket was the first place i checked after Hobbit first suggested it. With the cowl and water catch basin removed, using a mirror and the feel of my fingers i went around the valve cover and it was all dry, no sign of leak or oil grime.

Then i went under the car to look up past the oil pan. with the cowl removed more light came through and made it easier to see with a mirror. there was oil grime in the timing chain cover area around where exhaust comes out of #1 cylinder, as the upper most circle shows in the marked-up diagram i posted before. Then there was another wet spot at one of the corner bolts that hold the upper oil pan to the block - this one Patrick mentioned could possibly be drippings from the upper leak point.

Then i did remember from reading here that a stuck PCV valve could cause leaks. So I took mine off and it does rattle clearly, so i put it back. But there was grime on the valve cover near the PCV valve/tube and there was what looked like caked oil residue on the end of the PCV valve that resides inside the valve cover, I will post some pics later.

Just out of curiosity, does the dealer need to drop the engine to replace the timing chain cover gasket?

 

Thanks for the reply Pat.

So while all this is happening, today i parked the car on the street and I think i might have forgotten to power it down (headlights were on at the time). When i returned 4+ hours later, headlights were very dim, car was off and would not power on into any mode. Parking button light was on, clock was on but barely visible. Doors were locked (does this mean i DID turn the car off? because Prius does not allow locked doors in Ready mode), and smart key didn't work. Every time when I press the power button the check engine light came on.

So I said shit, i drained the 12V. I got the car jumped, thank god the HV battery did not drain. Then i wanted to check the 12V voltage on the MFD but forgot how. So I drove 25 minutes highway home so i can look up the procedure to check the 12V voltage. Is 25 minutes at 60 mph enough to recharge the 12V battery?

Now I'm trying to figure out what happened:
All 4 doors were locked when I returned, this means car was IG OFF at some point. With doors locked headlights would turn off automatically, regardless of switch position. But when I came back headlights were very dim and tails lights were also on with the car OFF, I had to use the little metal key to unlock the driver door. what could have happened?

 

Thanks for the quick reply Pat.
I just measured the 12V, you are right, it's only 12.75V. I do not have a charger. 8 hours to fully charge - can this be done cumulatively through everyday driving, or is it best to leave car in Ready overnight?

I did not climb out another door, I came out the driver door. Could this scenario be possible: left car on with lights, car shut off automatically to protect HV battery (3 blue bars after jump start), locked itself automatically after 30 seconds, but did not shut lights off.

 

Update: i took the car to the dealer, even though both the shop foreman and service writer saw the hanging oil drop and felt wet oil in the areas i indicated, they insist putting in a small bottle of dye in the engine oil and have me drive 500 miles, then they will check with UV light to be certain of the leak and the location. Then they will file claim with Toyota warranty.

They tell me they are following warranty claim procedures for oil leaks. It does make sense but this will push the mileage even closer to 60K (58300 mi right now) and that concerns me. How long does it take Toyota warranty to process a claim? Can they usually approve/reject over the phone after receiving all information in the same day? I have never dealt with car warranties. I'm thinking about having them file a claim right now so the next time i come in they can just supply the additional dye test results and get a decision right there (saves me another trip).

And how much control or say does the dealer have in convincing Toyota to honor the claim? So far the shop foreman took pictures, pulled all dealer visit histories and carfax report to make sure it's not in a collision. Thanks all.