CAT 3412 oil/fuel exhaust leak

I wonder if anybody could help with this problem.

We have 2 x 3412 CAT 1400hp ( 1800 engine hours). Recently noticed an oil / fuel leak coming from exhaust on stbd engine and creating a sheen or small slick on the water.
Only evident after engine has been used and well heated through (not present when cold or even at 70 degrees C

Engine is running fine, possibly fuel pressure down slightly, other pressures / temps all ok.

Don´t know if it´s relevent but an oil change was done and tappets adjusted.

Turbo chargers have been checked. Oil samples are being done and fuel return cooler and gearbox oil cooler being pressure checked.

Does anyone have any information / advice they could give me, would be highly appreciated.

Thanks, Ron

I think you might be on the right track with the fuel cooler.
when checking the turbos, was oil noted in the exhaust side at all?

did the oil leak in the exhaust is too much..when do you last overhaul the engine?... what is the sos result? hope i can help.

Ron, not sure if i have got the right Ron, but my name is George Jeffreys did i work with you in Airlie Beach in 2004, if so would be great to get back in touch