1fz oil leak under exhaust manifold

[pdot]

Hi team, newish 80 series owner here after owning a couple hundos. This is a 1997 LX450.

Wondering if I can get some input on this oil leak on the passenger side of the engine from under the exhaust manifold. The oil pan is rather wet underneath with the occasional drip as shown in the photos. Valve covers look ok.

This doesn't seem to be one of the common oil leaks, unless I'm mistaken. Maybe the upper pan gasket? Or oil cooler? Any other ideas?

 

[ppc]

Front part of oil cooler looks to be the likely culprit.
Clean it off good the recheck it in day or two.

 

[Kernal]

What does the lower front of the engine look like, got a photo?

Could be the angle of the photos but the oil pressure sender looks like it's sitting too high above the oil cooler (?aftermarket part or some
sort of adapter screwed into that port, or??

@pdot : Do you know if the engine has ever been removed/replaced?

Ditto: wash it off well then watch where it appears.

 

[pdot]

@Kernal lower front looks dry. Doesn't get oily until the pan area.

Unknown if the engine has ever been out/replaced. There does appear to be some kind of connector on the oil pressure sender. Is that normal? [Edit: looking at pictures of a new sender, seems normal.]

 

[Kernal]

Yeah, oil sender looks normal but on closer inspection the oil cooler cover appears to have sealant
pushing out along the bottom edge, that normally is sealed with a crush-type metal gasket. So if the oil cooler
had been taken off in the past and they found corrosion around the mating surface and/or forgot to order the correct
gasket, they may have sealed it with FIPG when they reinstalled the cooler cover.

So oil cooler cover or timing chain cover on that side are two possible sources of the leak.

Wash that area off well and watch it closely, take frequent photos until it shows up.