I am not aware of anyone running anywhere close to 15K mi and doing oil analysis. Keep in mind - absence of evidence is not proof to the contrary. I think longest reported was 5K and at that point oil was mostly fine, with slightly elevated metal particulates.

So no, there is no direct evidence that oil change at 15K miles would harm your F-type. Nobody here drove F-type for 5+ years, changing oil at 15K and then had to rebuild engine as a result. I suspect with time we will see some cases, but it won't be mine.

There is, however, evidence that other cars with extra-long recommended oil change intervals suffered adverse consequences. Similar technologies, similar engine oils. There is also evidence that 'normal use' is overly broad and should not be applicable to all climates/geographic areas that it presently does. Lots of dust, harsh winter, extreme summer heat, high humidity... all will reduce effective oil life. The same idea as EPA mileage and actual mileage, most of the time they don't line up yet EPA is one that is always advertised.

There is also historical evidence from other attempts (e.g. 'liftemine transmission fluid', 'lifetime coolant') that always ended in greatly reduced component life at long service intervals to suspect it is marketing decision, and not based on actual engineering principles.

 

I dont remember the mileage- but they were right about the mileage. The logic is that if you drive 20,000 miles a year, then you are cleaning the engine out. Unless its the odd guy that drives 20,000 miles in the city as a cab driver, to them they will just silently take the car back.

I have found something wrong with the 12/15000 oil change in my personal application. I dont use mine much, and in following their suggestion for the first 3 years wound up with valve train noise on the forth. Cleaned the daylights out of the engine and noise gone.

Also, the science that was not previously known at time of design of the DI engine is that the quality of oil can greatly reduce carbon buildup. Its widespread knowledge now. So not unlike those who want to make performance mods, I change my oil more frequently to preserve the power I have.

Incidentally, GM and others have also reduced their intervals. So it seems that several companies were wrong. Perhaps Jaguar isnt. Its cheap not to gamble in this case.

 

Really well put sir.
Yes look no further than the historical precedence with supercharger oil and transmission oil.

 

If someone did, and the results were positive, would you change your oil changing habits?

 

No because I race my car, and it is entirely different use-case. Now, suppose I only commuted in it. In that case, yes it would. I would require more than one report from more than one user showing the oil to be acceptable at 15K.

 

Yes, racing does introduce an entirely new set of variables. Anyone remember how long it's been 12yr/15k at JLR? Pretty sure that's what it was in 2011 when I bought my first one. So at least 5 years and hundreds of thousands of cars and we know of nothing to suggest that interval leads to any problems correct?

I mean, we've had our fair share of other issues but not premature engine failures or sludge buildup that are systemic. Right?

Lets also stay focused on the topic at hand which is JLR's interval recommendation. It really doesn't matter if company xyz recommended something different because they didn't build our cars and we don't use their specs.

So, I can't help but to conclude that saying the 12yr/15k oil interval is crazy is, based upon........nothing. I'm not here to change anyones minds though. Just having a conversation and gathering different views and opinions. We'll all do what we feel is best with our toys and that's just fine.

 

Dont speak for me and several others here and even way more on the LR site who have had premature chain failure.

Given how small the sample pool is in JLR its already a very high number. Regardless, no one should have to replace a timing chain for $3500 below 40,000 miles.

And yes the fact that no other car manufacturer has been spared using the same design does speak volumes of the potential problem. And since they have a much larger sample pool we should look to them as well.

 

Well, I'm not sure what timing chain failure has to do with a oil change interval but I am sorry to hear about your trouble with it. I agree that shouldn't be a failed component below 40k miles. That's a hardware problem though.

Also, 2 years or 20 thousand miles is drastically different from our stated intervals so I don't understand why you want to pull from a sample pool that doesn't compare equally to our own. That is useless data.

 

My service manager specifically warned me about this, he said he have seen quite a few of these on both Jags and Land Rowers that just follow interval and none on the cars that are "cared for" (his words). This is anecdotal, so don't ask me to show you definitive proof...

 

I am not convinced by this argument. Sure, there are some difference but fundamental technologies (e.g. direct injection), tolerances in block machining, and chemistry in engine oil formulation and additives are basically the same. We can and should consider what is going on with other car brands in determining what is likely an area of concern in ours.

For example, recent diesel emission scandal - while only one manufacturer was caught outright cheating, turns out all of them are failing real use tests.

 

A number of classic cars suffer similar problem (you'd think industry would understand and fix this issue by now). What happens is that chain and cam sprocket make high speed contact and tend to wear out unless properly lubricated. Some wear would happen anyways, and chain tensiometer will pick up slack. Typically tensiometers are dual action - spring and hydraulic (not sure if this is the case in Jags, but probably is) and can gunk up and not work as effectively. All of this combined can lead to loose chain - causing chain slap. If this left alone, eventually chain jumps and engine destroys itself. Typically, there are signs of chain slap on valve cover or block that you can see if you open it up. You can also hear noisy start that quiets down if tensiometer is failing but not yet completely failed. Old oil makes this problem substantially worse - it increase sprocket wear and leads to premature tensiometer failure.

Now, what I describe is typically seen on engines that are 30+ year old. If Jags are having this issue this early, none of them will make it to 30 years on original chain operated as-is.

I personally plan to have chain inspected and tensiometer replaced (out of pocket if necessary) at 4 year mark. It is certainly a weak spot for these engines.

 

So let me ask you, how does looking at data from terms far greater than the term in question help you? I am truly trying to understand you two's logic in that.

 

What is being described there is a problem due to design or materials or both. It does not have anything do to with whether you change your oil at the JLR specs or before. One case in evidence of this is Queen and Country himself. He clearly does not extend his oil changes to 15,000, I'd guess much less in fact, yet his chain still failed.

 

Interesting your Forum name is OverBlown considering you prescribe to the 15000 mile manta..... My forgein car mechanic (40 years in the business) stated that if you drive this car like your grandmother you'll get away with 15000 miles service intervals. If you drive it like you stole it change it at 7500..... I think I'll go on the side of caution.

 

Engineering is often not an exact science, but a set of educated guesses based on available data. We know that engines are comparable in manufacturing processes (e.g. cylinder lapping techniques, alloys used) and oils are comparable in chemical characteristics. If you see one set of engineers estimating that acceptable oil change interval is Z, and other A then see Z blow up. Based on that you can conclude that 'blow up' is an issue between 0 and Z, and you need to determine if A, within natural variability, is also prone to 'blow up'.

In other words, if you see two wires on the ground. See someone electrocuted by one of them, what would you assume about the other wire?

 

Very good point. It could be the case that Queen and Country became aware of this issue AFTER his chain failed and this is his understandable reaction. After all, it would be much cheaper to change oil ever 7.5K for 5 years than pay for a chain fix. Perhaps he will clarify this point?

 

Dont worry, not many know. And thats the point!! folks who dont know just believe all is well. I can explain in detail what the timing chain has to do with the oil change interval. But first read it from an authority on the subject, so as to take the pursuant academic debate and hairsplitting out of it.

Please use the thanks button if you find my contribution helpful. Do note that even Jaguar is not giving you this heads-up.

ILSAC To Add Timing Chain Wear Test To GF-6


Gasoline direct injection (GDI) and turbocharged GDI (GDI-T) engines are expected to capture 60 to 65% of the North American new passenger car market by 2019. GDI and GDI-T engines are headed for dominance and for good reason: better fuel economy, better torque, and better power from the same size engine versus indirect port fuel injection (PFI) engines. A turbocharged GDI engine can also be downsized and deliver the same peak power along with significantly better fuel economy.

Blue area is GDI forecast
Red area is PFI forecast
Source: HIS Global Insight
Compared to PFI engines GDI and GDI-T engines have several unique features:

1. increased production of fine carbon particulates during combustion which can enter the crankcase via blow by and cause excessive wear
2. increased fuel dilution of crankcase lube oil (cylinder wall wetting by side-mounted direct fuel injectors allows fuel to contaminate the lube oil)
3. increased oxidation and deposits from higher operating temperatures and pressures
4. higher initial cost than PFI engines for the higher-pressure fuel injection system

The one component that suffers the most from accelerated wear in GDI and GDI-T engines is the metal timing chain, which drives the camshaft(s) off of the crankshaft. Excessive wear can cause the check engine light to illuminate and could result in very expensive internal engine hardware repairs. Excess wear is evident in chain elongation which can disturb valve timing leading to degraded performance and higher engine out emissions. Researchers are not yet sure about the exact wear mechanism—it could be abrasive wear from carbon particles suspended in the lube oil or an interaction between carbon particles and the lubricant or both. A typical timing chain connecting the crankshaft and the overhead cams is shown below.

ILSAC has proposed a timing chain wear test for their new ILSAC GF-6 passenger car engine oil specification click here to view the draft specification proposed for first API licensing on 1/1/2017. Ford is developing the chain wear test in a 2.0 L I-4 EcoBoost GDI-T engine. The wear test procedure is proposed to assure that ILSAC GF-6 engine oils can meet the timing chain durability requirements in GDI and GDI-T engines.
The rest of the world is faced with the same challenge. The European Automobile Manufacturers Association (ACEA) is discussing the problem with counterparts in the oil and additive industry with a view of developing a suitable test in the furutre.
The timing chain is constantly facing unfavorable mixed and boundary layer lubrication regimes. Click video link below to learn more about boundary layer lubrication. Mixed and boundary layer lubrication regimes are not the ideal hydrodynamic lubrication regime where metal surfaces well separated by a protective oil film. GDI and GDI-T engine field experience shows in addition to timing chain wear more aggressive oxidation, viscosity gains, and related increases in varnish deposits. None of this is good, so improvements in lubricant performance is nessesary to enable the successful introduction of this new engine technology.
Lubrizol is developing high performance advanced additives packages for high performance GDI and GDI-T engine technology which will soon dominate the passenger car market. Lubricant additives can minimize wear, combat oxidation and control deposits. New lubricant chemical additives require development involving years of test results before commercialization. Given long lead times for lubricant product development, testing, and commercialization there is a growing urgency to proceed with the ILSAC and ACEA programs if the requested commercializations dates are to be met.

 

Sorry I was not clear.
I did 1 year oil changes- till my chain problem developed.

Look this is no joke. Type in Honda to Hyundai, i.e. best to medicore in super reliable engines- they have all had timing chain problems if there is a direct injection pump on the chain. Its a flaw of the design.

Mark my words- none of us will have a timing chain that goes past 100k- until they develop better oil, or oil change intervals. I am willing to bet money if someone likes.

 

Thanks for the very informative article, but it sounds to me that this is a GDI weakness for which a solution has not yet been identified. I didn't see any discussion that suggested more frequent oil changes offer any benefit or a solution to this problem.

 

Thank you Foosh.
I have seen a few early adopters in the high performance area suggest more frequent oil changes. The same type that adopted synthetics long before OEM did. However lets not muddy up the water by leaning on the word of tweakers.

What we do know from reliable sources is that oil will cause sludge if left in too long. The question we need to ask is how long is too long. Unfortunately OEMs cant be trusted in this matter.

One other data point is that not everyone has suffered chain wear. And the $64,000 question is in what way is their driving habit different. In either case, you can see there is a lot of grey area and when in doubt...dump it out.