Why does the the Ford 7.3 PSD take 15 qts of oil?

[Thomas1190]

My dad has owned his '02 Ford Super Duty with the 7.3 Diesel since new. He always does his own oil changes and every time i wonder why does this engine take 15 quarts of oil? I asked my dad and he also wonders the same thing. Is it because its a diesel? Maybe because its turboed? Whats the reason for such a large sump of oil? All i know is it will be expensive as [censored] to put synthetic in it lol

 

[Dualie]

IT's a diesel. It runs a lager sump because it works the oil harder than a gasoline engine.

Especially the HEUI motors like your 7.3L that uses the engine oil under very high pressures (up to 2,300+ PSI) to fire the fuel injectors. This puts a lot of stress on the additive package of a HDEO especially the anti foam property's.

Also if you use the PSD like it was built to be used, Heavy towing and WORK, that puts a lot of stress on the oil. Turbo charging and soot loading are other issues that lend themselves to having a larger sump capacity.

With a good HDEO you can expect a very long life out of your PSD. I have a Pair of them both over 350,000 miles.

 

[Duffman77]

+1
Dualie beat me to it. Larger sumps give you longer change intervals as well.

 

[Colt45ws]

Yup, a HEUI Diesel. 15 quarts is not actually all the oil, either. IIRC, there is another couple quarts in the high pressure oil system you cant really drain.

 

[DieselTech]

complete capacity of a dry 7.3 is 16qts. After a drain 15 gets it done. The HPOP res doesnt hold that much really.

The HPOS is one of the main reasons of the capacity.

 

[Colt45ws]

Hm, I thought it was more. Does it have some sort at anti drain back or is it pumped in in a way that it wouldnt need one? I ask because some seem to take longer for the romp to settle down after a sump and filter change. Or am I off base and that romp is something else completely?

 

[DieselTech]

When you do an oil change on a 7.3 it does not drain the HPOP resy completely. Approx 1/2qt remaining. The reason for the rumps after your change is because the ICP is not getting an accurate read. A High pressure crossover line could help this problem and smooth out your all around idle quality.

A HPX line bridges the 2 high pressure oil rails together located in the heads and evens out the pressure and takes pressure spike away. It helps greatly in cold weather in ridding the cold rumps