High mile 4.6 Ford - Ok to use heavier oil?

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Jun 5, 2016
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574
Location
California
I’ve spent pretty much all day researching the forum on this topic. I’ve found some rather interesting threads all the way from 2003 up to now on whether or not people have used something like 10w40 in a 4.6 modular motor. It’s 50/50 and very subjective..

My vehicle:
- 2002 F150 with 226k
- Vehicle used daily in Northern California (Hot summers 100°+)
- Have used PUP 5W20 w/FL820s and Fram XG2 filters since ownership from October 2018 (purchased w/187k miles)
- Has always consumed 1 quart around the 3K mark of the strict 4k mile OCI
- Motor gets a little louder in the summer months (can audibly hear valves working more and 1.5’ish loss mpg)

A lot of threads on here speculated that 10w40 was just not correct for a 4.6 simply because it’s not what the manufacturer called for, however we all know that BITOG’ers have superior analytical evidence that says otherwise..

My question now is, would I create/develop an issue(s) with cold start rattling (cold here being 50°) if I move to 10w40? I like Pennzoil and don’t mind moving over to their high mileage flavor however they offer only 10w30 in full syn.. other options are:

- Mobil 1 HM Full Syn 10w40
- MaxLife 10w40 Syn Blend

Would like to hear what you all have to say
 
You will find the same thing here. Some will say "oh no", some will say "sure why not". I say with that many miles, assuming it is running good, run what you have been running, dont change a thing.

 
You will find the same thing here. Some will say "oh no", some will say "sure why not". I say with that many miles, assuming it is running good, run what you have been running, dont change a thing.

Even with the 1 qt oil consumption condition?
 
Maybe the same brand stuff you have been using, maybe 30wt, maybe 40 wt....point being, the oil thickness will not be a guarantee in oil consumption reduction.
I read through that thread you linked earlier. Someone said that they took a small penalty in mpg using a 40wt but gained 1k miles for the 1 qt consumption condition their 4.6 has vs having to top off every 3K miles on 20wt and 30wt. I guess it’s very minimal when it all boils down..
 
I read through that thread you linked earlier. Someone said that they took a small penalty in mpg using a 40wt but gained 1k miles for the 1 qt consumption condition their 4.6 has vs having to top off every 3K miles on 20wt and 30wt. I guess it’s very minimal when it all boils down..
Some people look at oil consumption like an issue, which it is, mechanically. And of course, everything gets a return.

What I see, is that every 1000 miles, you have to add or "refresh" the oil in the sump, by 1\4 quart give or take. I'll bet at the end of your 4000oci, if you got you oil analized, the oil would be good for several more 1000, just because you refreshed it.

You also are mindful enough to check your oil, which is a plus.

Sure, an engine that uses no noticeable amount if preferred, but with close to a 1\4 of a million miles, how much gain could you get.

Many here, use 0w40 MI FS in many applications not by the book with great success. Not saying to do that, but i dont think the weight will help ypu much in the using oil dept. Maybe in the longevity dept, maybe not.

That is why I recommended just staying the course you are on.

Good luck.
 
Some people look at oil consumption like an issue, which it is, mechanically. And of course, everything gets a return.

What I see, is that every 1000 miles, you have to add or "refresh" the oil in the sump, by 1\4 quart give or take. I'll bet at the end of your 4000oci, if you got you oil analized, the oil would be good for several more 1000, just because you refreshed it.

You also are mindful enough to check your oil, which is a plus.

Sure, an engine that uses no noticeable amount if preferred, but with close to a 1\4 of a million miles, how much gain could you get.

Many here, use 0w40 MI FS in many applications not by the book with great success. Not saying to do that, but i dont think the weight will help ypu much in the using oil dept. Maybe in the longevity dept, maybe not.

That is why I recommended just staying the course you are on.

Good luck.
I appreciate the thoughtful response =)
 
What problem would one think there would be with running a 10W-40 oil in that engine?
Cold start rattle from timing chain guides to oil passage issues from what I’ve read.. None of it analytical but what people felt could happen
 
If you're worried about startup rattle, there's an easy way to find out. :)
Personally, I'm using 5w-30 in my 5.4 mod motor with >260k on it. No startup rattle that I've noticed.

Good to hear! I may stick with 5w30 PUP or even try QSUP this time around. Looks like my local Walmart has the QSUP gallon jug for $18.82 right now too
 
No engine is harmed by an oil with a higher HT/HS. If you were researching this all day I’m surprised you didn’t see the discussions on this.

The winter rating controls the cold weather performance. If your starting conditions permit then try a 20W-50 and see if it helps.

Owner’s manuals give recommendations on grades, not requirements.
 
The only concern I would have are the orifices that feed the tops of the heads & valvetrain-one cold morning start will tell you all you need to know on whether you're getting enough oil up top or not! Clackety clack clack would mean no...
 
Cold start rattle from timing chain guides to oil passage issues from what I’ve read.. None of it analytical but what people felt could happen

I just did timing chains / tensioners / guides / arms on my 01 4.6 with 135k-ish miles on it. I ran 5w-30 because that's what I had when I did the chains in october. Even with new parts, it had some timing chain rattle on a cold start. With the 0w-20 that's in it now, it rarely makes any noise.

My 245k mile 5.4 2 valve is using 5w-30 and has no timing chain rattle (also did chains / guides on that ) but horrendous piston slap and the cylinder walls are smooth or scored. It doesn't seem to care for some reason.
 
I just did timing chains / tensioners / guides / arms on my 01 4.6 with 135k-ish miles on it. I ran 5w-30 because that's what I had when I did the chains in october. Even with new parts, it had some timing chain rattle on a cold start. With the 0w-20 that's in it now, it rarely makes any noise.

My 245k mile 5.4 2 valve is using 5w-30 and has no timing chain rattle (also did chains / guides on that ) but horrendous piston slap and the cylinder walls are smooth or scored. It doesn't seem to care for some reason.
My old GMs had slap and 10w30 helped them. May try it and see if you care to, worth a shot.
 
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