high Mileage 4.6, use 15w40?

[MNgopher]

Well my '99 4.6 hasn't blown up yet using 5w40. Of course, it didn't blow up using 5w20 either, so go figure...

My point is simple: We've seen a boatload of used oil analysis using xw20's and xw30's on this board with the Ford Modular motors. The vast majority of them look excellent.

There is very, very little information on using an xw40, though I know I am not the only one. I just took a sample out of mine late last week, so I'll get a baseline on 5w40 versus 5w30 and 5w20.

My suspicion is that xw40 oil works fine in these motors, but may not be the best overall choice, unless chasing another condition. In particular, this post is working against and oil consumption issue, and I can vouch that my consumption was cut to about a 1/2 quart over 6000 miles, as compared to 1-1.5 quart per 6000 miles using 5w30 or 5w20. In that sense, it worked. Of course, my fuel mileage is off, the engine feels sluggish, etc... I'll see what the used oil analysis says when I get it.

Honestly, running a 15w40 over the summer months here wouldn't bother me a bit. You already know about winter, so I don't need to mention that

Contrary to popular belief, we do get some warm to down right hot weather in this part of the country.

 

[mf150]

gopher-

let me know if you have the same hp/mpg loss that I did with Mobil 1 15W-50. The 4.6L had 150,000 miles on it when I tried this.

 

[mf150]

quote:

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Originally posted by Michael SR:
dan, i looked at the shop manual at a ford dealer, the clearances are the same. (wish i'd had the opportunity to measure for myself.) i'm guessing the true difference is the intended use/application. the cobra R is marketed as a "racecar," so the oil temps at the end of a long track session might mean the 15w-50 is as thin as a 5w-20 is during light/regular street use.

the clearances are actually tight, compared to what i'm used to seeing. from memory (this is ~4 years ago) both the rods and the mains had .002" as an upper limit, with middle of the range roughly .015".

i actually did not intend to say i think the original poster should use a thick oil, i just wanted to point out the folly in making a blanket statement that modulars require thin oils. (a blanket statement even ford doesn't make, apparently.)

one thing i have noticed about (4V, i never had the opportunity to try this with the 2V) modulars is oil pressure. it's extreme. i put a mechanical gauge on a few i built while on the dyno, and i was shocked. the 100psi gauge is pegged through the upper half of the rev band.

i think they also have some sort of inherent oiling problem, either in the drainback, or maybe the pan/pickup design. during a lot of dyno pulls, i noticed the oil pressure drop all the way to zero, then slam all the way back to the peg, somewhere in the upper rev band. it did not happen consistently, but i noticed it on multiple cars, including ones that were near stock. this pressure loss was less than 1 second long, and so fast that the stock gauge and/or idiot light would never catch it, i never saw it until i used a mechanical gauge.

something else about those engines, the cam bearing bores are almost always out of line. one or more of the cam journals would usually be ultra tight. (i don't know if this plays into ford's recommendation of thin oils, but probably not.) i had a few problems with that when using aftermarket cams and/or mega rpm/hp, so we started to just machine the heads to insert cam bearings and all the problems vanished. (stock the cams ride directly on the aluminum of the head.)

quote:

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Originally posted by mf150:
seems like complete BS to me, especially since my pal has a cobra and uses 5w30 (4V DOHC 4.6L).

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since you asked nicely, let me backup my "BS" by asking you to google "cobra r 15w-50," you'll find plenty to corroborate my assertion, including mobil's own website.

quote:

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Originally posted by mf150:
I'd put my money on 5w30

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pay up!

thing is, i don't think any of us have yet seen an engine fail due to using the "incorrect" viscosity. so who's to say what's "incorrect?"

i worked at mti, then helped start houston performance, and built plenty of modulars. i'm definitely familiar with them, tuning them, racing them, and i was doing so since '96. (i'm out of the industry now.) i never saw an oil related failure (except for oil starvation, which might still be some inherent oiling problem as i described earlier, but open-tracked modulars had a habit of blowing up unless the oil system was modified), so i can't tell you anything about what oils work best in them, because they all worked fine to me. i never even saw any oil pump breakages that were widely reported in the high hp cars, so i can't comment on that either.

i see nothing more concrete in your anecdotal evidence, even empirically it's not enough data, especially since we have evidence to the contrary. (that thick oils don't hurt modulars.) but you assert that a 10w30 should be more than enough, and i can't argue against that. ford would argue against that on the cobra R, but we don't have the full story there, i'll concede that.

again, i'm not trying to comment on the use of 15w40 vs 5w20, just trying to bring a saner view to the debate.

thanks.

-michael

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Dude, you're saying that the clearances are the same...Cobra R versus what?

As far as I know the Cobra R is the only car with that configuration engine (5.4L 4V).
Closest thing would be a Lightning engine with DOHC heads.

My point is that you cannot draw any conclusions based on a Cobra R engine...all 300 of them. They are a whole nother beast.

Our 97 lariat with 215,000 plus miles is running on all compression (as of 8-23-04) with nothing but Mobil 1 10w30 in the sump. Sound like more than anecdotal evidence, and we are talking about a 2V most likely.

Did you read the list of mods. that I posted above regarding the Cobra R specs.

[ September 27, 2004, 03:10 AM: Message edited by: mf150 ]

 

[Michael SR]

quote:

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Originally posted by mf150:
Dude, you're saying that the clearances are the same...Cobra R versus what?

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versus any other modular.

quote:

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As far as I know the Cobra R is the only car with that configuration engine (5.4L 4V).
Closest thing would be a Lightning engine with DOHC heads.

My point is that you cannot draw any conclusions based on a Cobra R engine...all 300 of them. They are a whole nother beast.

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i feel differently. it's still a modular, there's no design change anywhere. here's what's the same to regular production:

oil pump (common)
block oil passage design (indeed, it's just a regular 5.4L block)
bearing journals (common)
bearing clearances (common)
cam timing chain tensioners (common, oil-fed)
valvetrain (indeed, they're just regular 4V heads)
rod length (5.4L)
piston compression height (5.4L)
piston pin size and clearance (common)
piston ring sizes (common)

in other words, it's a parts bin special.

what's different:

rod manufacturer (this is actually manley, not carillo as you reported)
crank (steel version of cast 5.4L)
pistons (i forget who makes them)
oil pan
oil cooler
unique front cover to deal with 4V heads on tall 2V block

if anything, the pan and cooler should allow it to run thinner oil.

quote:

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Our 97 lariat with 215,000 plus miles is running on all compression (as of 8-23-04) with nothing but Mobil 1 10w30 in the sump. Sound like more than anecdotal evidence

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that actually sounds a lot like an anecdote to me.

you know, when i worked in italy our shop had a shop truck that had over 300k km on it, all short trips. it had an 1100cc engine, and was sometimes used to tow cars to the shop. it had never had its oil changed, ever. as it burned oil, we just added more.

but we didn't add good motor oil. we had this big drain where we placed all cans (except coolant and brake fluid) upside down, in order to catch the last few drops. this had hydraulic fluids, engine oils, gear/transmission lubes, etc. that slop is what we used to fill the shop van. it was still running strong when i left, and the engine had never needed repairs of the longblock, and certainly nothing oil related.

that is an anecdote. it's true, it's interesting, but i don't think it says anything about what kind of oil was good for it. if it does, we've all been doing the wrong thing.

-michael

 

[MillerMan]

thanks for the comments people, I have decided to try MC 15w40 next summer, when I'm boat pulling

 

[97flairside]

That knocking on the those cold mornings is called piston slap. Common problem in the modular motors. I had it then was told to switch to Mobil 1 10w30 Full Synthetic with the fl820s filter.

 

[MillerMan]

na I don't think it was pistion slap, it only lasted a few seconds till oil hit the bearings then all quite. doesn't pistion slap last a little longer?

the knock sure sounded like crank bearing to me

the other slight knock i heard I think was timing chain, that noise was much quiter and lasted for about 10 seconds, this noise got worse with new heavier oil, the bearing knocking noise was gone with new heavier oil.

 

[honus402]

It's not a bad crank bearing and it's not piston slap. It's due to the 2000 rpm "race start" which is supposed to heat the CAT quicker, thus reducing emissions. If you listen carefully to any of the newer V8s (Ford, GM, etc) you'll hear it. These new engines start within 1/4 revolution and rev to 2000 RPM before there is any oil to the bearings. May be good for emissions, but it has to be **** on engine life.

 

[Dr. T]

FWIW, I owned a `97 DOHC Cobra that I used Mobil 1 5w30 from day 1. The oil turned black after about 3k and consumed 1qt. every 2k mi..

From what I know now, I would be using a synthetic 5-40 as a minimum.

Yes, it's an OHC...but so are 99% of European engines...they don't use pushrods and nobody there uses 5w30 oils (in the traditional sense).

 

[MillerMan]

well my cougar had a tach in it, it never went to 2000 rpms on start more like 1200 to 1400 rpms before dropping down.

 

[Gene K]

Entire LAPD fleet of 4.6L Fords gets 15w40. No adverse effects.

Gene K

 

[mf150]

okay, you all sold me, but my personal preference is at most a 10w30, because I've personally experienced a major drop in performance when switching to 15W-50 MObil 1. Maybe 15w40 will be different...I hope it is you.

As for the "anecdotal" debate between SR and myself, I don't consider your statement to be true. Experience is just as legit as specs. or used oil analysis. My philosophy is use what works for you. It's your car/truck and you are paying for it.

I just know that our 97 4.6L had a compression check done all all cylinders and came back with virtually no wear out. We've been running on nothing but Mobil 1 10w30.

15W-40 and 15W-50 are overkill in these engines.

take a consensus over at www.f150online.com and see what people are using with great results, even in extreme racing conditions.

You could also try www.mustangworld.com and see what they are using in SC, NO2 , and N/A Mustangs pumping 500RWHP. Just to give a wider spectrum of experiences to draw from.

 

[MNgopher]

mf150, yes, my fuel consumption is up around 4% versus running 5w20 or 5w30. I didn't see much difference between those two (statistically indiginifcant anyways), where 4% worse is defintiely noticeable.

As far as hp, the closest my truck will ever get to a dyno is driving by one on the way to work, but my butt dyno says the engine is more sluggish and less responsive. Of course, we all know how reliable that dyno is

I'm still keeping an open mind for the used oil analysis results (just sent in a 6000 mile run on 5w40). I suspect 5w20 or 5w30 will be going back in the sump, but I'm still going to ride the year out (if I can stand the winter) to see how it does.

I will say the reduction in oil consumption was nice, but wieghed against fuel costs, the consumption was not that big of a deal.

 

[mf150]

quote:

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Originally posted by MNgopher:
mf150, yes, my fuel consumption is up around 4% versus running 5w20 or 5w30. I didn't see much difference between those two (statistically indiginifcant anyways), where 4% worse is defintiely noticeable.

As far as hp, the closest my truck will ever get to a dyno is driving by one on the way to work, but my butt dyno says the engine is more sluggish and less responsive. Of course, we all know how reliable that dyno is

I'm still keeping an open mind for the used oil analysis results (just sent in a 6000 mile run on 5w40). I suspect 5w20 or 5w30 will be going back in the sump, but I'm still going to ride the year out (if I can stand the winter) to see how it does.

I will say the reduction in oil consumption was nice, but wieghed against fuel costs, the consumption was not that big of a deal.

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Please keep me posted if you decide to do a used oil analysis with a heavier weight. It would be interesting to see how a 40 weight would fair in a 4.6L.

Maybe we will finally see some verifiable evidence that the only reason for 5W-20 is CAFE related. It would also show that Ford is brainwashing their technicians into telling everyone that their clearances are measure in thousandths of an inch (even though this is true). and that a thicker oil will not lubricate as well at higher rpms.

thanks.

 

[MNgopher]

UOA was sent in earlier this week. Look for a post next week when I get the results. I'm curios as to what it will say (and I have a hunch about it)!

 

[pmt]

Originally posted by MNgopher:


"There is very, very little information on using an xw40, though I know I am not the only one. I just took a sample out of mine late last week, so I'll get a baseline on 5w40 versus 5w30 and 5w20.

My suspicion is that xw40 oil works fine in these motors, but may not be the best overall choice, unless chasing another condition. In particular, this post is working against an oil consumption issue, and I can vouch that my consumption was cut to about a 1/2 quart over 6000 miles, as compared to 1-1.5 quart per 6000 miles using 5w30 or 5w20. In that sense, it worked. Of course, my fuel mileage is off, the engine feels sluggish, etc."

I'll add my 2 cents. 96 T-Bird 4.6, about 55,000 mi. Was consuming over 1 quart of Mobil 1 5w30 in 5000 mi. Switched to Mobil Delvac 1 5w40 for a couple changes - only used about 1/2 pint/5000 mi. Noticed no decrease in gas mpg, but I imagined little less power? Anyway, I'm trying to find a "synthetic" 5w30 that doesn't consume so much. Currently at 3000 mi on Havoline synthetic 5w30 - oil level still at the FULL mark. Will see how it turns out. I know - Group III etc, etc. But studying the used oil analysis on the Havoline, it looks like a pretty good oil.

 

[2004 F150 4x4]

pmt have you tried the GC 0w-30? It may help with your oil consumption issue?

 

[pmt]

quote:

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Originally posted by 2004 F150 4x4:
pmt have you tried the GC 0w-30? It may help with your oil consumption issue?

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I have (6) quarts of the magic green stuff sitting in my basement waiting for next summer's oil change. May the best oil win!