524td oil change confusion. Oil drain passage Curiosity

[Vixen21]

I have owned a 1986 Vixen motorhome with a 524TD engine for about 20 years. Has Air research turbo with oil cooler.
A 7.5qt oil capacity, with” larger oil pan than car”
In the last two oil changes there seems to be 1.5qts hiding somewhere. I’m only dumping about 6qts.
Hence only adding about 6qts to reach full mark on dip stick. was 7.5qts previous years.


History, two years ago:
Replaced turbo charger
Timing belt, water pump, thermostat
Added blow-by canister
Adjusted valves,

Engine seems to run good, with multiple 3000 mile trips to Fla from Iowa. I have not noticed any oil consumption on dipstick or changes.

This is really concerning to me as thinking there is an oil passage is obstructed?
Any ideas?
Any thoughts or direction will be greatly appreciated.

[gadget73]

I think the VIxens got the same pan as the Lincoln did. Mine ends up with 2 gallons per change with the filter. I think the Ford manual says 7.5 liters.

My filter holds probably a quart. Thats really the only place I can think of where you might be holding that much oil, assuming the dipstick reads full before draining it. Can't think of any oil lines besides the turbo drain line and the oil cooler plumbing. Don't see that the turbo line could hold that much. You'd be burning a lot of oil if it was't draining anyway, the oil would be getting past the seals if it was backed up into the bearing. The oil cooler on the cars is not high enough to drain back into the pan, so I don't think it actually gets changed anyway. Its not very big either.

Ever pop the oil fill and shine a light down in the rocker galley? Maybe a clogged return hole might hold some oil but I'd expect the cam cover to be leaking oil and it probably burning oil if it was that full since oil would be above the valve seals.

[SteveKerwin]

"Maybe a clogged return hole might hold some oil but I'd expect the cam cover to be leaking oil and it probably burning oil if it was that full since oil would be above the valve seals."

That might very well be the case with this one. I hope Vixen21 double-checks it as well.

[gadget73]

oh, totally unrelated question for OP, what does the Vixen cam cover have on it? Internet rumor has always been that Vixen bought the surplus M21 inventory from Ford when they realized that nobody wanted diesel Lincolns. I'm just curious if you have a Ford cover, a BMW cover, or if Vixen had something custom made for it. Also sort of curious what accessories you have, Ford, BMW, or other. I know my alternator and AC compressor are different than what BMWs got.

[Vixen21]

Are there any 524td mechanic still around?
Im in Midwest near Cedar Rapids Iowa,
I see some possible shops at East Coast West Coast and Florida.
Im about limited to changing injector pump, injectors, timing belt, valve adjustment. I don’t even have access to a cam clamp anymore.

Gagget, the valve cover on my Vixen has Bmw stamped on it!

My email for possible future repairs help/advice.
Mwblacksmith@ juno.com

Jack