Hi, guys. Thought I'd post another analysis. This is the longest (not terribly long... I know) I've gone so far on an oil change in this car since I bought the car. Wear trends remain stable. Boring report. I'm happy!
2007 Mercury Grand Marquis 4.6L V8 | Valvoline Synth Blend 5W-20 4,263 mi
- Thread starter BackwoodsAL
- Start date
IMO, the 4.6 and 5.4 SOHC engines need somewhat frequent oil changes to keep the timing chain guides happy. 4,000 miles is about the longest I go on my 1997 F250 5.4 SOHC engine, now entering 270,000 miles without a teardown and still no oil usage between changes.
dnewton3
Staff member
You can easily extend the OCIs out; double to 10k miles. Plenty of proof that distance is perfect sound. And, as an added benefit, the wear rate will probably go down! Save money and reduce wear; what's not to like about that?
dnewton3
Staff member
Actually, I've gone 10k miles on really inexpensive Rural King dino oil, and it did just as well as any synthetic.
See these as proof:
https://bobistheoilguy.com/forums/threads/5w-20-ford-4-6l-engines-uoa-testing.269435/page-3
You'll perhaps note that the wear rate for Fe is at or lower than 1ppm/1k miles for ALL lubes, whether it be cheap dino or expensive syn. There was absolutely no difference in the performance of those lube choices; there is no statistically significant difference between any of those UOAs and they completely far in line with marco data normality.
So, yeah, 10k on a semi-syn is a total no-brainer. And, what's wrong with saving money? The inference I get from you comment is that it's somehow a risk to do this, but there is TONS of data to show it's perfectly safe.
The more laughable thought is throwing money away on the oil AND the UOA. After all, why pay for the UOA if you're just going to ignore what it's telling you? That's just doubling down on waste.
See these as proof:
https://bobistheoilguy.com/forums/threads/5w-20-ford-4-6l-engines-uoa-testing.269435/page-3
You'll perhaps note that the wear rate for Fe is at or lower than 1ppm/1k miles for ALL lubes, whether it be cheap dino or expensive syn. There was absolutely no difference in the performance of those lube choices; there is no statistically significant difference between any of those UOAs and they completely far in line with marco data normality.
So, yeah, 10k on a semi-syn is a total no-brainer. And, what's wrong with saving money? The inference I get from you comment is that it's somehow a risk to do this, but there is TONS of data to show it's perfectly safe.
The more laughable thought is throwing money away on the oil AND the UOA. After all, why pay for the UOA if you're just going to ignore what it's telling you? That's just doubling down on waste.
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Good info, thanks!
dnewton3
Staff member
There is no reliable data that shows any correlation between OCI and timing guide wear. And without correlation, there can be no causation. Generally the chain guides in these engines get destroyed because the guide tensioners start to leak at the gaskets; that had ZERO to do with the OCI duration, and more a result of simple heat cycling and luck. Hence, that's a farcical myth.
The old 2v mod-motors are generally very long lived and are not sensitive to oil brand/grand/OCIs.
The old 2v mod-motors are generally very long lived and are not sensitive to oil brand/grand/OCIs.
Yep, keep giving them the 20K intervals and see how long they last.
dnewton3
Staff member
Folks who do 3k mile OCIs said that about people who do 5k mile intervals.
Folks who do 5k mile OCIs said that about people who do 7.5k mile intervals.
Folks who do 7.5k mile OCIs said that about people who do 10k mile intervals.
See a pattern here?
I've done 15k mile intervals upon occasion in several vehicles over the years. I've pulled valve covers off and looked for sludge. I've pulled UOAs and looked at soot and insoluble counts. Even the Ford/Conoco SAE study I referenced ran the OCIs up to 15k miles for the tests.
As I said before, there is no (zero, none, zilch, nada) correlation in data that shows timing chain guides will wear out sooner with longer OCIs in this engine series. The guide failures are typically because they start to run loose and allow the chain to slap against the guide liner, thereby eventually beating it to death. If you are diligent, you very well may catch it by listening for that slap, and also see it in the UOAs with Al and Fe spikes. But all that has ABSOLUTELY NOTHING to do with the OCI duration.
I would admit there is a practical limit to any OCI. At some point, the additives will be overwhelmed. The continamination will become too great. The vis too thick from oxidation. I do agree there are detrimental effects from over-runing an OCI. It's just that your view seems limited by mythology and rhetoric, not facts based on data.
Since you seem adamant about your position, then please show me the evidence (credible facts like SAE study, or similar) that directly attributes timing chain guide lifecycle to the OCIs. I'm all ears. But please, make sure it's creditbly sourced, and not some YT vid or shade-tree ol' timer who has nothing but suspiciion and wife's tales.
I really enjoy your posts on the TCB theory relating to OCI's and of course one of it's by products, ROI. Cheers.
You do realize how many 300,000 mi+ 4.6L have done that on Amsoil right?
I do have some data on this but it's from a larger vehicle.
40 Quart Sump + 4 qt add oil every 18,000 mi.
Conventional Oil (14.5 TBN D2896)
6.0 average mpg
Operating Conditions: 6 to 30 psi of turbo boost, cruise to max.⁴
Typical after 40,000 mi on oil.
Oxidation: 18 abs/cm
Nitration: 12 abs/cm
Soot: 0.2%
TBN 6.0 (D4739)
I think it would have went 60,000 mi easily but that was the max Donaldson would approve their extended drain filters for us at that time so we just changed it.
Ran it like that for 1.2 million miles and tore it down for leaking head gasket (Liners walked) and since that's a major undertaking did the inframe at that point. Valves all still had good seal, bearings had approximately another 400,000 mi left in them. No sludge just the usual million mile light varnish in non-contact areas.
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