API and ISLAC Oil Burning in Cars

[pdawg7]

Hi Folks,

I apologies if this has been done to death. I searched and found heaps of hits but none that really looked like what I'm after.

I have a Toyota with the infamous 2azfe oil guzzling engine. I've noticed in the manual its says that the required oil for it is ISLAC- GF4 or higher. When I went to find this oil in my local store I struggled, all I could find was API specs. SN, SM or SL. I asked my local parts guys who said SN is the same is ISLAC-GF5.
So I’ve been using that, a Valvoline Syn Power API SN. But since the car has developed the infamous oil burning issues lately I’ve started digging. I’ve found many manufactures have oils which meet API-SN and then different oils in the same class which meet ISLAC-GF5. Many such as Valvoline and Penrite, make a big marketing thing out of meeting ISLAC-GF5.

Am I correct in thinking these standards are NOT equivalent? ISLAC-GF5 is a higher/different spec to API SN? Can anyone shed any light? I’m wondering are ISLAC grades more resistant to sludge and varnishing effects which seem to lead to the piston ring drain ports blocking on these Toyota Engines.

This also got me wondering, could this be one of the causes some of these engines develop oil consumption issues? It seems not all 2azfe engines develop the problem. Most people in parts stores, garages, and even forums like this when they talk about oils talk about them as full or part synthetic and then the viscosity ie 10w-40 etc. Its unusual to have someone talk about the specific grade of oil.
en

 

[Garak]

SN is not the same as SN/GF-5. Normally, I'd say look for the API Starburst up front, which indicates ILSAC certification, but in your neck of the woods, that's going to be difficult to find.

Basically, GF-5 lubricants, at least in 5w-30 and 10w-30, are thin within the grade. If you find a 5w-30 or 10w-30 in A3/B4 on the shelf or E7, E9 or E6, E7, E9, then it's not a GF-5 lubricant.

Others from your neck of the woods will have to chime in with more specific details, but if you are looking for an SN/GF-5 oil (or something very close), you might be best off grabbing an A5/B5 option. Certainly not all SN/GF-5 5w-30 options are A5/B5 up here, but every A5/B5 example here is also SN/GF-5, since it's a less robust spec.

 

[pdawg7]

Interesting thanks for that!

I've since sourced some GF5 here with out too much issue. But my main question (sorry if it wasn't clear) is what is the difference between an SN and a GF5? Could this difference be one of the causes of blocked piston oil return ports?

Thanks!

 

[Garak]

GF-5 tends to be thinner within the grade, with respect to HTHS. GF-5 is also, generally and loosely speaking, what limits phosphorus content in what are known as ILSAC grades (0w-20, 5w-20, 0w-30, 5w-30, and 10w-30) within the API regime. To be honest, while there's nothing wrong with an SN/GF-5 oil where specified, in your location, I'd be "happier" with the A3/B4 options.

A good example of the difference would be you can have something like Mobil Delvac 1 LE 5w-30 in CJ-4/SN and E6, E7, E9. It's certainly SN. Now, it's a robust synthetic HDEO as well. It has reduced phosphorus already thanks to E6. But, it's HTHS is 3.5 or greater, thanks to the E specifications and therefore cannot be GF-5. If you take an SN/GF-5 5w-30, you'll be having an HTHS of 3.1 +/- 0.1. GF-5 does bring a few more things to the table than the basic SN specification, but it is primarily a fuel saving specification.

SN versus SN/GF-5 shouldn't matter much in relation to cleanliness, all things considered, assuming you're not trying to stretch the limits of an oil change interval, at which point an A3/B4 might be more suitable in any event.

Here is a link from Lubrizol which might be able to provide you with much finer details. There are also lubricant handbooks available, such as this one which outline parameters for various specifications.

 

[pdawg7]

Thats awesome thanks very much!

 

[BrocLuno]

Originally Posted By: Garak
SN is not the same as SN/GF-5. Normally, I'd say look for the API Starburst up front, which indicates ILSAC certification, but in your neck of the woods, that's going to be difficult to find.

Basically, GF-5 lubricants, at least in 5w-30 and 10w-30, are thin within the grade. If you find a 5w-30 or 10w-30 in A3/B4 on the shelf or E7, E9 or E6, E7, E9, then it's not a GF-5 lubricant.

Others from your neck of the woods will have to chime in with more specific details, but if you are looking for an SN/GF-5 oil (or something very close), you might be best off grabbing an A5/B5 option. Certainly not all SN/GF-5 5w-30 options are A5/B5 up here, but every A5/B5 example here is also SN/GF-5, since it's a less robust spec.


+1

 

[SonofJoe]

In broad terms, API SL is ILSAC GF-4 without the Sequence VIB fuel economy test. It also leaves out a few other cats and dogs like the Gelation Index test.

API SN is ILSAC GF-5 without the Sequence VID fuel economy test, the Gelation Index and silly stuff like the Phosphorus Volatility restriction.

The above really applies only to the so-called ILSAC grades (30 weight and below). For 40-weight oils (and above) you only get API specced oil and these also have less restrictive limits on things like Phosphorus (or ZDDP if you prefer) and TEOST.

ILSAC oils are very much a North American thing. You don't tend to find them in Europe and I doubt if they're that common in NZ. That said, GF-4 & GF-5 oils are generally rubbish (they're way too volatile). You're far better off going for the API equivalent oil.

The causes of your Toyota's oil consumption problem are however not rooted in this difference between ILSAC & API specced oils. If anything, using a GF-4/5 oil, as opposed to the API equivalent oil, would in all likelihood have made the problem worse.

I've been out of the game too long to give you definitive answers but from what I've seen of the Toyota problem, I reckon it's caused by hot blow-by progressively stripping the light front-end of your engine oil, routing it through your PCV system, into your air intake and into the combustion chambers where it burns badly, leaves behind gunk which either plugs your piston drain holes or sticks the oil control ring. Accumulation of the gunk is a slow but steady process which is why the onset of the problem only manifests itself late in the life if the engine.

You could have helped to prevent (or slow down) the accumulation of in-cylinder gunk by using a very low volatility engine oil (a low Noack oil in industry parlance). Sadly once the gunk has built up, it's seriously difficult, if not impossible to reverse the problem simply by using a different engine oil. Really the problem calls for a full engine strip down, cleaning up the pistons and drilling out the gunk from the drain holes.

However if you can't justify this, then try using a low spec, very heavy Group I oil in your engine; something like an API SG 20W50 (a 20W40 would be preferable). You want the aromaticity of the Group I to soften the gunk, the low Noack of the 20W oil to stop further build-up and, for want of a better word, the hydraulic pressure that a heavy base oil imposes in the ring pack (you need something capable of squeezing itself behind the rings). The SG oil will contain less Ashless Dispersant which both helps reduce Noack and allow a high percentage of heavy base oil in the blend. In this instance, additive is not your friend so avoid oils with lots of specs (like A3/B4, etc).

Hope this helps....

 

[Olas]

It's either going through the rings or the stem seals. Replace them and the consumption will reduce/stop.

 

[SonofJoe]

Toyota issued Tech Bulletin TSB #0094-11 about the AZ-FE oil consumption problem. Google the code and download the PDF for detailed info.

It sounds like it's a piston/rings problem rather than one of seal leakage. The oil consumption problem typically kicks in after 60,000 miles.

Toyota stopped using the 2AZ-FE engine in 2012 so I'm guessing a) your problem isn't covered by warranty and b) the cost of a complete strip down is more than the car is worth. In which case trying a heavy, low volatility oil might be worth a shot.

 

[Olas]

You can re ring it in a weekend for less than the cost of 1 weeks worth of fuel.

 

[SonofJoe]

Yes, if you know exactly what you're doing and don't ascribe any value to your own labour, expertise or the tools you use. Take the engine to any UK Toyota dealer and he will charge you an arm and a leg to do the work!

The OP didn't say how old his car was but say it's ten years old. What's it worth? Maybe £1,500 say (it's only a Toyota!). Suddenly that dealer strip down and fix looks very bad value for money. Better to just keep putting cheap oil in it until it dies of old age.

 

[d00df00d]

Originally Posted By: SonofJoe
API SN is ILSAC GF-5 without the Sequence VID fuel economy test, the Gelation Index and silly stuff like the Phosphorus Volatility restriction.

Appreciate the detail in your post. I'm... shall we say, "puzzled" by the Group 1 oil advice, but overall it's nice to have serious propositions on the table to discuss.

Question: Why do you think the phosphorus volatility restriction is silly?

 

[SR5]

Hey Pdawg,

Welcome mate.

API SL, SM, SN is a good base level spec. From there ILSAC GF-4 , GF-5 is mostly an American thing that pushes things to the thin side to chase fuel economy. The other way is the European way with ACEA A3/B3/B4 that pushes things to the thick side to chase long drain intervals. They are all good oils and using SN without GF-5 will not be the cause of your problems. It's a Toyota thing, and to be honest going a little thicker and avoiding GF-5 probably helps a little due to all the reasons Joe gave above.

So what to do now? You and I have much the same oils in our shops. I would go thicker like Joe said, and I would go for a mineral 15W40 like Castrol GTX or Shell HX5, they are cheap, they are everywhere and they are good.
https://bobistheoilguy.com/forums/ubbthreads.php/topics/4293744/

Don't waste your money on a full synthetic if your are burning lots of oil, it won't help and it's a waste of good beer money. A semi-synthetic 10W40 would be my second choice, they are also cheap and easy to find. Both will be API SN and ACEA A3/B3 or A3/B4, but that is what is avaliable around here. Very hard to find a simple SN only oil that doesn't carry a few other specs.

Maybe Silk will drop around for a chat, he's from NZ too and knows what he is talking about.

 

[d00df00d]

Originally Posted By: SonofJoe
Yes, if you know exactly what you're doing and don't ascribe any value to your own labour, expertise or the tools you use. Take the engine to any UK Toyota dealer and he will charge you an arm and a leg to do the work!

The OP didn't say how old his car was but say it's ten years old. What's it worth? Maybe £1,500 say (it's only a Toyota!). Suddenly that dealer strip down and fix looks very bad value for money. Better to just keep putting cheap oil in it until it dies of old age.


I know it's common to compare the cost of the repair against car's value, but that not the way to go.

The best way is to look at how much your car is worth as-is, plus the cost of the repair, and then look at how much you'll be spending each month to keep it on the road. With that money, what are the odds you could find a better car than yours would be post-repair?

If those odds are high, the repair isn't worth it. Run your car into the ground or sell it immediately and buy what you can buy. Otherwise, you're better off doing the repair.

For example, say I have a beater that's worth $500 as-is and needs a $1000 engine rebuild, but after that it should cost me about $50/month to keep on the road. Not a lot of good cars available for $1500; maybe they'll cost me less than $50/month, or maybe they won't. It's possible I could end up with something better, but it doesn't seem likely. So, if I know my car will be good after the repair, I should go for it. It's more of a known quantity.

OTOH -- not all that realistic, but it serves the point -- if I have a commuter car that's worth $10,000 as-is but could use 5,000 in repairs, and would cost me $100/month to keep on the road afterward, it's a different story. This is new car money, easily. $15,000 would make for a nice downpayment on a nice new car with a warranty, and $100/month would cover the monthly payments and then some. In that scenario, the repair isn't worth it.

 

[SR5]

Originally Posted By: SonofJoe
... then try using a low spec, very heavy Group I oil in your engine; something like an API SG 20W50 (a 20W40 would be preferable). You want the aromaticity of the Group I to soften the gunk, the low Noack of the 20W oil to stop further build-up and, for want of a better word, the hydraulic pressure that a heavy base oil imposes in the ring pack (you need something capable of squeezing itself behind the rings). The SG oil will contain less Ashless Dispersant which both helps reduce Noack and allow a high percentage of heavy base oil in the blend....


Those old school API SG 20W50 mineral oils are not as common now days.

Castrol GTX 20W50 is API SN and Shell Helix HX3 20W50 is API SL.

Joe, would you go those 20W50's or would you go the API SN - GTX 15W40 / Shell HX5 15W40 ?

I assume they are all pretty much Group 2 now days.

 

[FCD]

Changing the valve stem seals has given new life to my engine, it burns basically no oil now, just saying.

 

[SonofJoe]

Originally Posted By: d00df00d
Originally Posted By: SonofJoe
API SN is ILSAC GF-5 without the Sequence VID fuel economy test, the Gelation Index and silly stuff like the Phosphorus Volatility restriction.

Appreciate the detail in your post. I'm... shall we say, "puzzled" by the Group 1 oil advice, but overall it's nice to have serious propositions on the table to discuss.

Question: Why do you think the phosphorus volatility restriction is silly?


As the engine oil world (and especially the US) has both moved away from basic Group I base oils to Group II & III's, and moved to lighter engine oil grades (which contain less heavy base oil) the ability of the oil to solublise 'stuff' has decreased. It's all to do with the de-aromatisation of the base oil and the fact that aromatics content generally increases with heaviness .

TBH, for a fresh oil, this matters not a jot (unless maybe you're trying to get a particularly insoluble additive into something like a GTL based 0W20). However as you load up the oil with grot, especially grot that really shouldn't be there in the first place (such as partially burnt engine oil) then it becomes extremely important. Once the solubility limit is reached, stuff will plop out on the handiest, nearest metal surface. Traditional sludge type oxidation products dump out on the sump tray as the oil cools down. Burnt oil insolubles dump out on the sides of the piston. By running an oil based on heavy Group I (something like AP/E Core 600SN or Shell HVI 650BS), you're using an oil that, whilst not good from an oxidation point of view, has a HUGE solvency reserve. Of course its far easy to keep something in solution before it plops out. Getting something back in solution, once it's out, is far more tricky, which is why trying to clean up piston deposits is so difficult. But in theory, given infinite time, it should/might go back in...

The Phosphorus Volatility limits are what happens when self-interested people play silly beggars and game the existing engine tests to seek commercial advantage. High levels of Phosphorus volatility are an artefact of the Sequence IIIG test. It's what happens when you artificially keep oil at 150C for 100 hours on an engine that's being thrashed and who's test limits allow oil consumption to reach stupidly high levels before the test is declared invalid. The only link to reality is a field trial that just happens to have been run in conjunction with said self-interested party. So yes. I think 'silly' is an apt word to use...

 

[d00df00d]

Thanks for the explanation. I'd imagine that if one went the Group 1 route, the oil would have to be changed quite frequently, yeah?

On phosphorus volatility, to make sure I understand: Are you suggesting it's a pointless thing to consider because it's only a real factor in conditions that normal engines almost never see?

 

[2004tdigls]

this link should help, it includes the extended warranty letter and the tsb

https://www.toyoheadquarters.com/threads/excessive-oil-consumption-on-2az-fe-engine-lsc-ze7.362/

 

[Olas]

Originally Posted By: SonofJoe
Yes, if you know exactly what you're doing and don't ascribe any value to your own labour, expertise or the tools you use. Take the engine to any UK Toyota dealer and he will charge you an arm and a leg to do the work!

The OP didn't say how old his car was but say it's ten years old. What's it worth? Maybe £1,500 say (it's only a Toyota!). Suddenly that dealer strip down and fix looks very bad value for money. Better to just keep putting cheap oil in it until it dies of old age.



Well you probably already paid for the tools a long time ago, I know I did. And it's not a case of valuing your own labour at zero but at valuing your own work at what the Toyota dealer would charge, only because you're paying yourself you save that money.
And by just letting it burn and topping more up there will be other problems that manifest along the way, taking more time and effort. Best to fix it now, and save a fortune no in the long and short term.