98 F-150, High Consumption

[Jackpot01]

Hey All,
About a month ago I posted about switching to 5w20 in my Dad's F-150 Click Here

Now his consumption of oil is WAY UP. He was using a 10w30 Mobil Drive Clean. He is about 1000 miles in to using Motorcraft 5w20 and he is down about 1 to 1.5 quarts. He hasnt had any issues with the truck, its running good and smooth and no smoking. Any suggestions?

Eric

 

[haley10]

I hope Dad isn't too mad at you. Remember, I liked his idea of the Syntec Blend?

I'm not surprized at the consumption.

I have no experience with Auto Rx, so no recommendations here, but the Drive Clean may have built some deposits affecting ring seal and that's why you are having the issues with the thinner oil.

I might wait for another oci or two and see if it stabilizes now though. I wouldn't pull the plug on it yet.

 

[Gene K]

LAPD uses 15W-40 HDEO in their 4.6L OHC Fords. So I would think anything up to that Viscosity should not cause any harm.

If the 5W-20 Motorcraft is causing some consumption issues I would switch to a 30 Weight.

5W-20 MC is a excellent oil but not all engines are going to like it.

As stated above you could run some Auto-Rx through it to clean up any ring deposits that may exist.

High consumption with the 4.6L is not unheard of though.

Gene

 

[Whimsey]

quote:

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Originally posted by Jackpot01:
Hey All,
About a month ago I posted about switching to 5w20 in my Dad's F-150 Click Here

Now his consumption of oil is WAY UP. He was using a 10w30 Mobil Drive Clean. He is about 1000 miles in to using Motorcraft 5w20 and he is down about 1 to 1.5 quarts. He hasnt had any issues with the truck, its running good and smooth and no smoking. Any suggestions?

Eric

---

Something just doesn't seem right. Am I to understand that your father's truck went from consuming 0 oil with 10W-30 Mobil Drive Clean to consuming 1 to 1.5 quarts per 1000 miles with it's first change of Motorcraft 5W-20

! Unless the Mobil DC really hardened the seals and the Motorcraft cleaned up the hardened seals I just don't see how you could have that drastic of sudden oil consumption. As much as I'm a fan and user of Motorcraft 5W-20 you might want to think seriously of going back to a 10W-30. Trust me, it's best to keep peace with your father. Since 10W-30 has not done any visiable harm and even if it has, ignorance is bliss and it probably won't show up for a while anyway

. But keep Dad happy

.

Whimsey

 

[Jackpot01]

I recommended he stick with it for the OCI and see how it goes. Consumption could stop in the next 500 or not I guess so the only way to find out would be to run it. The only other suggestion I could think of is add Mobil 10w30 for the make up oil. That may just thicken it up enough to cut the consumption down.

Eric

 

[02supercrew]

Are you getting any leaks from the head gaskets...especially on the right side just above the starter?

Really sounds like you are leaking some oil.

 

[Jackpot01]

UPDATE Well my dad's truck is doing GREAT on 5w20. The consumption was WAY up for the first week on the MC 5w20. I know my dad was double thinking his new oil. After another week or so he added another quart and the miracle happened.....the consumption stopped. It hasnt used a drop at all now. I am really anxious to get a sample of this truck now.

Eric

 

[97tbird]

I'll post this here 'cause I'm going to have a similar situation:

I'm really happy to read that update, to see that consumption has stopped with the 5/20 in your dad's truck....

I'm thinking(almost decided now) of switching my 98k mile 4.6L(97 T-bird) to MC 5/20 too, and I'm a little scared of how the consumption is going to be when I switch from the M-1 Truck/SUV...

but I want to believe so badly in the MC 5/20 and give it a try...I really want to escape from the "thick-oil mentality" in the 4.6L mods.

Finally I have seen what I've been looking for: a HIGH mileage 4.6L from around 97/98 making the switch to 5/20 and being OK! That initial raise in consumption must have been scary, though: My T-bird will probably go through it, too, but I'll be prepared, and be patient, just like you/dad were. (I already have done Arx a few 1k miles ago, and the engine, to my knowledge is very clean)

I'll be making the switch to MC 5/20 with the start of winter: that way I can "test" the 5/20 in milder(not really hot) conditions. You guys think that's a good idea?

[As the bird is going be driven little, if all is good, I'm going to use it for 6 month OCI's.]

a few related questions:

(A)is MC the thickest 5/20 among Castr/Hav/MC/Mobil/Pennz? (non-syn oils)

(B) would mixing a qt of MC 10/30 with 4 qts of MC 5/20 be a problem(because of syn-blend + dino)?

Thanks.

 

[MNgopher]

I've posted this before, but I also switched a '97 F150 with the 4.6 from a steady diet of 5w30 until 160,000+ miles to 5w20. No change in consumption (it was nil) until I sold it. I also switched my '99 with the 4.6 over around 80,000 miles or so. No change in consumption from 5w30 to 5w20. (Roughly 1qt per 4000 miles). I'm tryin Rotella T 5w40 right now in the '99, and I lowered comsumption a bit at this point (down 3/4 qt at 3500 miles).

MC was one of the thickest 5w20s on the market last I checked. On your list, Havoline is the thinnest, at 8.0 Cst. I had good luck running the Havoline though, with vis remaining rock solid on 5 and 6000 mile intervals.

Mixing some 10w30 in is no problem. THe 5w20 marketed as a syn blend is really just a Group II/Group III blend, technically all dino. Even if that were not the case, you still wouldn't have an issue.

Honestly though, I'd use just the 5w20. Its likely the 10w30 is of weaker strength in comparison to the 5w20 in the same brand, and it still isn't going to make your oil a 30w.

 

[97tbird]

quote:

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Originally posted by MNgopher:
I've posted this before, but I also switched a '97 F150 with the 4.6 from a steady diet of 5w30 until 160,000+ miles to 5w20. No change in consumption (it was nil) until I sold it. I also switched my '99 with the 4.6 over around 80,000 miles or so. No change in consumption from 5w30 to 5w20. (Roughly 1qt per 4000 miles). I'm tryin Rotella T 5w40 right now in the '99, and I lowered comsumption a bit at this point (down 3/4 qt at 3500 miles).

MC was one of the thickest 5w20s on the market last I checked. On your list, Havoline is the thinnest, at 8.0 Cst. I had good luck running the Havoline though, with vis remaining rock solid on 5 and 6000 mile intervals.

Mixing some 10w30 in is no problem. THe 5w20 marketed as a syn blend is really just a Group II/Group III blend, technically all dino. Even if that were not the case, you still wouldn't have an issue.

Honestly though, I'd use just the 5w20. Its likely the 10w30 is of weaker strength in comparison to the 5w20 in the same brand, and it still isn't going to make your oil a 30w.

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MNgopher,

Thanks very much for your reply. My mind is at peace with my decision now. I'll give MC 5/20 a try on my next change, and hope all goes well. I really hope so: I'll get good protection and save some money with 6-month OCI's...