I am guessing replacing that is an engine-out type operation?

A kindly local diesel tech did a visual inspection for me recently and he suspected there could be a leak from the area of the front main seal.

He could be right; I do get spots on my driveway. But then the lower half of my engine is still recovering from an HPOP disintegration a while back with 20 years of road use + a lot of oil covering everything, so I have to wonder if some of that is what shows up on the driveway.

am also in need of new injector O-rings to slow down the classic 'blue smoke mornings' (seems like there should be a good country song about those). so figure those largely create the need for a pint of oil to bring the level-on-stick back up once a winter.

in these recent warm months, oil level doesn't drop at all - but I still get those spots.

is a main seal tiny leak a bit inevitable at 20 years of age? seems familiar from old old gas engines I have been around.

or could it be a small leak only generating a drop or two when idling, which seems to move things a touch more than when transmission is in gear ?

 

Could just be your lpop leaking... best thing to do is clean everything real good , run the truck and see where it's coming from 👍

 

You have a couple places on the front for an oil leak. The most common being the engine oil cooler o-rings. If it's not that, then have a look at the front main seal, it's mounted in the LPOP and behind the harmonic balancer. You don't have to pull the motor for that. Heck, I've replaced the LPOP without even touching anything other than the belt, the crank pulley, the balancer and the LPOP....it's tight to get a balancer puller in there....but it can be done.

If it is the LPOP shaft seal...I'd probably order a new Melling LPOP...throw that in.

 

I like the lpop idea quite a bit more, will check that out. but would be two distinct areas on engine I expect.



edit - wrote that one while 2nd response coming in. wasn't really sure where 'front main seal' is located. would love to see a tore down 7.3 to poke around some day.

 

New pump comes with the seal.

Melling LPOP

 

First, CLEAN that nasty thing and find where your leak is coming from. Most leaks are cheap and easy to fix.

Second, the blue smoke mornings youre singin’ about are not going to be fixed with injector o-rings. You might get away with shimming the poppet valves - but the reality is that is a bandaid for worn/tired injectors. A fresh set of quality rebuilt injectors are $1300 for stock split shots with 30% over nozzles (or 160/30 single shots if you’ve got or want a chip and gauges).

 

Like mentioned above clean all the grime and **** and go from there.
If you do decide to get a new LPOP get a Melling high volume.

 

You could try putting UV dye in the oil to pinpoint where its coming from.

 

How has this story turned out, jackstraw?

I've become a fan of the UV dye approach, having just used it to chase down a hidden coolant leak on my engine. Seriously considering the "clean up and dye the oil" process as well to capture the source(s) of my current oil ooze(s).