Found a puddle of oil beneath the rear of the engine, after I'd run it on the highway for 60 miles. Traced the oil slick all the way up to the front of the engine, fresh engine oil. Coated the oil pan, driver's side steering components, frame & axle, starter. No oil on the other (filter/turbo) side. So it's side-of-the-engine specific. No oil on the engine sides above the oil pan gasket. Checked the oil blow-by bottle, it's dry. Stuck my finger up and wiped the front main seal, it's dry. Oil pan bolts are tight, and the gasket isn't really very wet, just a little greasy/dirty. Truck has 24K miles, no servicing in that area except for changes and cleaning breather blow-by bottle.

Any ideas where it's coming from? It just starts at the front of pan, everything else up in front is dry.

Truck is an '02 ETH/DEE, relatively stock except for 275's, Edge & a 40/35 turbo.

Thanks.

 

Well, OK, I'll just answer myself!

It wasn't engine oil. It was power steering fluid. As in the vent clogged open and throwing it out on a semi-warm day.

Just goes to show you, when you think it's impossible, check your assumptions and it turns out to be easy.