Doctorgilli

I have used only Mobil1 5W20 with a Mobil1 oil filter, changing both at around the 4000 mile mark. I have 330,000 kilometres on it now and it's running as new. At idle sometimes it runs a bit rough and smooths out again and I'm going to remove the egr valve and clean it up to check for it sticking or dirty with carbon.

ceasefire49

At start is pretty a much a common problem. I have tried it all smooths right out I have 277k did the complete timing deal with new lifters and the Bosch 4 hole injectors and new cops. Runs great burning about a at every 5k but that's only when I drive 600 miles a day at hiway speeds. Great engine I use the 5 30 mobile one with the wix filter.

TerragonSix

I use Motorcraft Synthetic Blend 5W-20. I change every 3000-3500 miles anyway. Been using Motorcraft in all the Fords I've owned.

I know with synthetics you can wait a bit longer to change them, I don't.

Oil is relatively cheap. Engines are expensive. And with a 5.4L 3v, I am not about to skimp out on oil. My truck has 225k; running 5w-30 would probably work great, but naaahh, I'm good.

Roofis

FordTechMakuloco has a video on maintaining this engine.

He recommends 5w-30 at the 1:15 mark in this video:
Here's another video on visualizing oil flow at various temperatures:

LariatDude

Your money your oil but 5000 is perfectly safe with Motorcraft oil. Do it myself and the oil is always dirty but still opaque. Also depends on how hard you run the truck in those 3300 miles I guess

SilverSport

I thought he recommended this oil after the repairs...is there any benefit to using this slightly thicker oil (when warm) after your engine is already experiencing the phaser/pin lock issues???

Bill

Doctorgilli

I don't get it either, the oil galleries don't expand in these triton heads as the reason for recommending the 5w20 to start with. IMO, using a good quality 5w20 along with 3000 mile oil changes is all that required to experience a good high mileage engine. When I lived in the Arctic for a few years, where I experienced -60 C cold, I saw the need for light weight oils and also saw failures from 30 weight oils used and over extended oil changes with low mileage engines. With this cold temp I saw tensioner failures as most damage caused.

TerragonSix

The way I understand it and it was explained, 5w-20 was recommended primarily for CAFE standards and fuel consumption. But for engine longevity you want to switch to 5w-30 full synthetic.

I imagine since 5w-20 synthetic blend has both conventional and synthetic oil (hence 'blend'), switching to full synthetic 5w-30 would simulate 5w-20 blend, but without the conventional oil, making it less likely to sludge up the engine.

It's an interesting school of thought, and makes sense. I'll switch to 5w-30 after the timing chain, phaser and oil pump replacement when the trouble starts.

SilverSport

sure and I get that but I don't know (and have not read) where switching to 5W30 on an older engine before the improvements are made is worth it...i believe at least one reason is the thicker oil when warm (the 30 part) might raise the oil pressure just enough to quiet it a bit...

having an older engine that experiences these issues right now, I don't know that going with a slightly heavier oil when warm is a good idea or not...

I have 122K miles on mine and have only changed the oil once since I got it (almost 3K miles ago) and I used 5W20 full synthetic oil...my engine is noisy but the oil still looks pretty clean, it doesn't leak anything and it still shows full on the dip stick so I don't believe it is burning much if any...

Bill

650NutKase

The difference between 5w30 and 5w20 ins't a noticeable one, noise-wise. The 5.4 3v has been spec'd for heavier oils elsewhere in the world. The USA mainly used the 5w20 for increased mpg's. Honestly, use what you want. It's more important to just change the oil vs worrying about wt or syn/conventional/blend.