Yea my owners manual and cap are both saying 5w20. So also confused lol

 

Either way I'm gonna try a OEM filter Incase but it came with ford filter when I bought the truck. Willing to give it a try tho. I will hope for the best. Like I said tho. Truck runs great. No performance issues. Just the knock. Put over 40,000 on it and it's not showing up worse yet. I've gotten shed to it. After the stereo it won't matter lol

 

I do have one more question why does my 99 5.4 call for 5w-30 oil and my friends 2001 5.4 call for 5w-20?

 

That's correct, but that's not all it says.

 

We just talked about that in this forum, - uhmm, here,-

https://www.f150forum.com/f6/rotella-15w-40-a-243892/

 

Ah yes. The Nutella thread...

 

Dang man, opened your Image, figured,- this is going to be good, but -



Yea, got slammed.

Was it **** or something?

 

Better?

 

- That's about what I expected; - from you lol.

 

So, - Best thing you can do for your engine in crankcase is exactly what the owners manual and Ford TSB suggests.

Run FL820's in the V8's and 5w 20w SYN Blend. Just the blend and you'll never have to worry about doing the very best you can for it,- in the crankcase.. Simple.

Using the incorrect Oil filter has proven very bad and hard the engine because the lack of proper anti-drain back valve operation. Then of course, there also that $5 little part that can cause catastrophic damage no matter what you do and over a period of time. The PCV valve. Problem here is no one makes a replacement valve with the proper margins other than Motorcraft. So it's very important for this engine to breath properly,- ALL of the time. This valve can prove priceless in order to achieve engine longevity.

All this is in your owners manual. If you don't have one, well that's no excuse. Download one here, -

http://www.fleet.ford.com/maintenance/owner-manuals/