I want to run a thicker oil but…

[Japanese]

I just bought the truck and I don’t know if it was neglected or not. The fact that it’s using so much oil has me leaning towards “neglected”.

Get a new valve cover gasket and take off one of the valve covers (whichever looks easier to remove) and take a picture of the valve train.
Then we'll have a better idea of what that engine looks on the inside - is there sludge or only varnish. You can also take off the valve cover after 4-5K miles with VRP and we can see if there any difference.
At 250K miles I bet your problem is not the PCV.

 

[F150…]

I agree with the Fallacy comment, let's be realistic when the OP says that the PCV Valve does not look normal, we need to ask what vehicle he had before where it looked normal. The OP needs to pull off the Valve Cover where the PCV goes in and see what is going on.

I don’t inspect the PCV valve on a vehicle unless I suspect a problem. Every PCV valve I’ve ever messed with was a simple mechanical device with a weighted plug on the inside. When pressure develops in the crankcase the gas can push the weight and escape to the intake. The one in the picture is just open with no weight inside and has wires that run to it. How does it work?

 

[GR_CoB]

All of these messages got something in common, and I support it. Below I will drop down one more link in support of these...

Plenty of Ford modular v8s were serviced with the all-fleet 15w-40 from the 55gal drum in the corner. You’ll be fine with anything from 5w-20 an above in it.

Around me farm trucks get whatever the tractors get, typically 15w40 or 5w40 whether gas or diesel.

Ran 10w40 in my 05 Expedition 5.4l with zero problems. Many mod motors got 15w40 for millions of miles. You will be fine running thicker.

The old 5.4 on the farm that pulls trailers runs 10w30 or 10w40. Never an issue.

If you rarely start it below freezing, and never below 0F, I would probably just put in whatever you use in your tractor.
Rotella T4 15W40 does everything at my place, except the road cars, but I do use it to top up the Focus as it seems to burn a quart every 3k miles now.

Ford themselves rec using 10W-40 oil in 5.4 engines with noisy valvetrains or consumption issues.
Were it mine, I’d use an inexpensive 15W-40 in it bought in pails to cut down top off costs.

Here is that link, welcome to the thickie side:

Post in thread 'MOBIL DELVAC™ 1300 SUPER be ok for my 3.5 eco boost'

Aug 21, 2025

I have MOBIL DELVAC™ 1300 SUPER SERIES plus SN 15w40 I am planning to mix 50-50 with Mobile 1 0/20. For 3.5 eco boost
Will this result in a massive explosion/ massive civilian deaths?

This EcoBeast did just fine on HDEO 15w40.

And here are a few more vehicles that ran on HDEO. I'd say you got nothing to worry about, except for how to spend the money you saved on oil cost.

• GR_CoB

• 

 

[GR_CoB]

My Nissan Armada says 5W-30. It is currently running on AmazonBasics Euro 0W-40, and next oil change going on Amalie Elixir 5W-50.

My Infiniti EX35 is on the first run of Amalie Elixir 5W-50. Engine is noticeably quieter, no power or MPG loss. Which is why I'll switch the Armada to it as well.

Once the stash of Amalie oil runs out - both vehicles will be on SuperTech Full Synthetic 15W-40. My climate and usage patterns allow it year round, and it's easy to get in any WalMart across the USA.

 

[F150…]

The part in the picture is a “pcv fresh air tube”. It doesn’t have a traditional pcv valve. I went through the troubleshooting process and it seems to be functioning properly.

 

[Cujet]

I bought a truck with 250k to use as a farm truck. It doesn’t leak oil and it doesn’t smoke but it’s using a quart of oil every 500 or so miles. I’m considering running a thicker oil to see if it slows consumption but I’ve seen so many oil experts online that say to not go heavier than the manufacturer recommended viscosity. It’s a 2004 F150 5.4L and the factory recommends 5w20. Twenty weight isn’t very thick. Would it be unspeakable to use good old 10w30?

10W-40 is the right viscosity for Ford 5.4L engines, despite what the specs say. This is very well known.

 

[Brian123]

I don’t inspect the PCV valve on a vehicle unless I suspect a problem. Every PCV valve I’ve ever messed with was a simple mechanical device with a weighted plug on the inside. When pressure develops in the crankcase the gas can push the weight and escape to the intake. The one in the picture is just open with no weight inside and has wires that run to it. How does it work?

You bought a truck with 250K on it, and you are using a quart of oil every 500 miles, all I can say is look for leaks or make sure everything in the PCV system is clear. When I talk about the PCV system I am talking about hoses and whatever baffle is in the Valve Cover. Years ago, a buddy of mine had a small block chevy and his car was using oil, he changed the PCV, still it was using oil, he ended up getting Edelbeock Valve Covers and there was no more oil usage. The old Valve Cover he took off had some junky metal vent that was clogged up.

 

[F150…]

The part in the picture is a “pcv fresh air tube”. It doesn’t have a traditional pcv valve. I went through the troubleshooting process and it seems to be functioning properly.

I’m now having doubts that this PCV tube is actually working correctly, but I’m also having a hard time finding the tube to buy. Does anybody here know the correct part number? all the AI chat bots are giving me the part number for the hose that connects this part to the to the valve cover

 

[kschachn]

I’m now having doubts that this PCV tube is actually working correctly, but I’m also having a hard time finding the tube to buy. Does anybody here know the correct part number? all the AI chat bots are giving me the part number for the hose that connects this part to the to the valve cover

Why do you keep listening to AI?

 

[F150…]

AI has provided me with lots of useful answers and doesn’t waste my time by asking me why I’m asking. Do you know the part number I need?

 

[kschachn]

AI has provided me with lots of useful answers and doesn’t waste my time by asking me why I’m asking. Do you know the part number I need?

If you say so. So far you haven’t been taking the advice here so you might be on to something.

As for the part number if you really cannot determine that then visit the dealer with your VIN.

 

[rydaddy]

7L3Z-9F695-A
PCV Tube Heater

The PCV "Valve" may be built into the drivers side valve cover.

 

[F150…]

If you say so. So far you haven’t been taking the advice here so you might be on to something.

As for the part number if you really cannot determine that then visit the dealer with your VIN.

What advice are talking about?

 

[Revving2Redline]

Schaeffer's 132 Moly with M1HM 10w30 or VRP 5w30 w Schaeffer's 132

 

[redhat]

If you have VRP 5W-20 on hand, keep topping off the ole 5.4 modular with it until you run out. After that, feel free to grab some 5W-30 or other viscosity of VRP if you want to keep seeing if it’ll clean anything up.

If you think the motor might be grimey inside, you can change filters. No need for a super expensive one if they’re being filed in the trash bin after 500-1000 miles.

 

[Plumb Bob]

What advice are talking about?

Re-read the previous posts. Lots of good advice given, especially by @Astro14

 

[Japanese]

Re-read the previous posts.

The man is already running VRP 5W-20 (that were most of the advices). Let's see what will be the oil filter after 2-3K miles and then we can go from there. Hopefully when he switches to 5W-30 VRP his oil consumption will get better, since there is no VRP in higher grade than that.

I had actually already purchased some VRP in 5w20 to use in another vehicle so I just used it in the truck.

 

[BC1]

My logic for staying with the 5w20 would be to help get in all the nooks and crannies before going to a thicker viscosity.

The PCV valve is disappointing. It doesn’t seem to have any obstruction but it’s not your normal PCV valve. I can blow through it and the line just fine but I don’t know how it works/closes. Pictured below.

View attachment 299147

Stop searching with AI. Listen to people who have experience with these engines. Put a 40 grade in the 20 year old "farm truck". Watch this video to find and inspect your PCV.

 

[TomYoung]

This is a complete fallacy.

The “nooks and crannies” fallacy, or the disappointing PCV valve? Maybe two fallacies here.

 

[EBruce]

I have an email from Lake how to find which oil works best for my application. After several recommended steps with testing, he recommended moving up a grade. Moving up is not going to create any new problems.


Find a good-quality oil, like the Valvoline Restore & Protect or Mobil 1 mentioned earlier in a 5W-30 and use it without any additional oil additive. WalMart currently has some good oil sales happening. Consider moving up to a 5W-40, also.

How did you get Lake's Email?