Fuel adatives....

[ArthurPE]

1.5 to 2% fuel dilution is low and pretty much typical...
in a 10 qt engine sump if the level stays the same that means you lost only 6.4 oz, 1/5th of a qt...negligible...

gas is volatile, it's vapor pressure is much lower than oil...so it 'cooks off' and is aspirated/combusted into the engine, the vapor would actually help clean the valves...ever see it spilled on hot asphalt? vaporizes very fast...

it's also got a lower density, so it passes thru the cyclone with a higher efficiency...where as the oil drops out...

I think the problem is the cyclone seperator...the cyclones don't work right, the sequencing valve, bypass valve, pressure regulating valve, something is sticking/gumming up, and not seperating the oil entrained air properly...

I'd like to see someone stick a simple baffle/filter on the output tube of the cyclone module and see if this helps...

the valves get very hot, that's why the oil cokes or 'tars' on them...

[RI_RS4]

1.5 to 2% fuel dilution is low and pretty much typical...
in a 10 qt engine sump if the level stays the same that means you lost only 6.4 oz, 1/5th of a qt...negligible...

gas is volatile, it's vapor pressure is much lower than oil...so it 'cooks off' and is aspirated/combusted into the engine, the vapor would actually help clean the valves...ever see it spilled on hot asphalt? vaporizes very fast...

it's also got a lower density, so it passes thru the cyclone with a higher efficiency...where as the oil drops out...

I think the problem is the cyclone seperator...the cyclones don't work right, the sequencing valve, bypass valve, pressure regulating valve, something is sticking/gumming up, and not seperating the oil entrained air properly...

I'd like to see someone stick a simple baffle/filter on the output tube of the cyclone module and see if this helps...

the valves get very hot, that's why the oil cokes or 'tars' on them...

Arthur,

Sorry, you're wrong. All of these fuel dilution measurements were performed on oil that had been extracted after the engine was run at highway speeds and reached operating temperature to allow maximal burn off. Peak fuel dilution is most likely in the 3-4% range otherwise. It's possible, but unlikely that Audi and VW have both missed an obvious issue with the cyclonic separator on engines lines like the 2.0 TFSI that have been in service since 2005.

These fuel dilution levels correspond to oil flashpoint measurements of 290F down to 230F, and are not normal for most gasoline engines. (The flashpoint is the point at which oil begins to vaporize.) Given that the engine operating temperature is normally in the 230F range, on average, under spirited driving rising to 270F plus, and recognizing that the local temperatures are even higher, it is not surprising that a significant amount of oil is vaporizing, along with the fuel, with some significant percentage passing through the cyclone separators. As long as the effective condensation point (pressure/temperature) of the diluted mixture that volatizes is higher than the expected designed maximum on the separator, the oil is going to pass right through. I expect that Audi and VW engineers who contracted this design out did not account for chemical attack on the oil by aromatic hydrocarbons in the fuel.

Certainly the separator could be redesigned, but this would require that more "bad stuff" be recycled back into the oil to contaminate it.

Not only do we see this issue from fuel dilution, but also we see significant deterioration of the ZDDP tribological layers intended to protect the bearing surfaces in the engine, as evidenced by increase Fe wear during high fuel dilution and increase of the amount of free Phosphorus in the oil.

BTW, all of this was predicted by us 2 years ago through extensive oil analysis, and the experience of my consulting Tribologist.

[P_G]

RI RS4, as much as I appreciate your vast knowledge in this field which is way beyond my comprehension it would suprise me that a company like VAG would be able to produce an engine that is prone to failure in such tightly regulated markets now.

I have no doubt that what you say is right, however I would wonder at the same time whether the engines are designed to be able to tolerate such events and therefore surely the important factor to determine is what is the life of these engines before expiry and the need for FSI engined car owners to replace before terminal damage. If they can still run with decent if not optimum performance for 200,000 miles or 10 years for example is that such a bad thing.

Thereafter if people wish to pull their engines to pieces during or after warranty to clean them then that is at their discretion. I realise the legal action system is different in the US however I would suggest that in UK and European courts what you are decribing ould be categorised as wear and tear attributed to a high performance engine, even on lesser FSI models.

[pippyrips]

it would suprise me that a company like VAG would be able to produce an engine that is prone to failure in such tightly regulated markets now.

It would surprise me if a company like VAG produced a suspension system (repeatedly) that was prone to failure in such tightly regulated markets - oh hang on, they have!

Seriously, I 100% believe there is something in this.

While an engine may take 100,000+ miles to actually break, would you be happy if the performance of the car constantly fell away until it blew? This could well be a contributing factor in why RS4's constantly fail to make claimed performance figures in the rolling roads.

The RS4 is sold as a 50k+ performance car so deterating performance (if proved) is totally unexceptable imho.

Our American friends have had good success in playing with the inlet manifold, but it’s just occurred to me a large chunk of the success could be because you simply cleaned the valves up? (Anto/Silver can you confirm?)

Looking at the pics in this thread, performance must be affected!

It depends to what lengths you want to go to avoid this but as my engine is about to be properly cleaned out I will do my best to avoid it gunking up again. I hope to be able to shed more light on the outcome soon

Of course, this is assuming it is gunked up inside but does anyone want to bet against it? (It’s a 56 plate with 18k on the clock for those contemplating..)

[AntoRS4]

to clean the valves it's a must, but my avant can now run from 0 to 200km/h in less than 15.4 sec. ( vag-com values not from the odometer, mean of both directions )
so i suppose that the intake job it's a full success.

[SR71]

RI RS4, as much as I appreciate your vast knowledge in this field which is way beyond my comprehension it would suprise me that a company like VAG would be able to produce an engine that is prone to failure in such tightly regulated markets now.

I'm not sure RI_RS4 is suggesting the engines are prone to failure, unless the US B7 community does have that observable characteristic?

From where I'm sitting, it does start to look as though the spec of the oil is not up to the job. I'm not sure what the VW oil specs say about longevity of the oil once in situ (absolutely nothing is my guess), but its about as much use as Gordon Brown in a recession to have an oil meet the 502/504 specs before its used, but suffer a 150F reduction in flashpoint once its been in the car for only 200 miles!

Similarly, if the clever Ingolstadt engineers designing their cyclonic seperator(s) only ever used nice fresh oil in their wind tunnel tests, maybe they weren't so clever after all?

Speculation I agree...

But you now have statistically significant, independent analysis proposing a mechanism for high oil usage, deposition on inlet/valve geometries and an emminently reasonable explanation for a reduction in airflow through the engine.

This fits other owners observations of:

1) Failure to produce the numbers on the RR
2) Hideously contaminated inlet tracts
3) Improvement in flow post-cleaning - I hope Caldy and pippyrips get some pre-post cleaning figures as well

Personally, I don't care what the inlet tract of our 2.0 TDi looks like as the car only produces 140hp. Even if it only produced 120hp, I didn't buy it for its performance and I'm happy to accept a reduction in its performance over the duration of its life. It gets me 60mpg and thats all I care about in that car.

However, in a performance vehicle like the RS4, I'm less willing to accept the deficit. Its already ~25hp down on 414...

I'd be staggered if any engineer involved in the cyclone design would be happy that within the space of a few thousand miles, the inlet would look like Caldy's and he'd concur he'd done a good job with the design? Especially if the shelf life of the car is 200K miles!

That said, it looks like RI_RS4's oil formulation is pretty good at resisting fuel dilution if it can run at 1% after 10K miles...

Who has an optic fibre they can bring along to a meet for us so we can each inspect our inlets?

Oooooooooooo eeerrrrrr!

[silverRS4]

The intake work makes a difference. I was able to benchmark the car after valve cleaning, but before the intake work; in other words, the baseline in performance was not established with dirty valves. For the type of performance that Anto and I see from our RS4's, relatively clean valves are necessary. I will probably have my manifold off for inspection within 30 days. I have been using the RLI synthetic oil and fuel additive since my latest valve cleaning, so it will be a interesting reveal.

[PetrolDave]

Got some of the Wynn's DIP3 liquid and aerosol from Camberley Auto Factors (nearest Wynn's distributor to me) at lunchtime, will try it when I get time.

[pippyrips]

Got some of the Wynn's DIP3 liquid and aerosol from Camberley Auto Factors (nearest Wynn's distributor to me) at lunchtime, will try it when I get time.

The spray only takes 5 minutes, get on it man!

[SR71]

For me its too early to switch over to RLI's oil when I have no data on what the Titan Fuchs is doing in my engine...but I'm going to send over the data to Terry on my next change which is imminent.

SilverRS4,

Whats the change interval (OCI) on RLI's Bio-Synth 5w-40?

I can't see any stats on http://www.renewablelube.com/pdf/Bio-Sy ... %20Oil.pdf.

Looking at the 2.0 TFSI owners experience on VWVortex Forums (http://forums.vwvortex.com/zerothread?id=4115371) we need someone to come up with a simple solution like that for the B7. They're ahead of us in the game and, whilst it looks like levels of oil contamination are heavily correlated with usage paradigm and seasonal weather, because I'm a long-term owner, the less s**t flowing around my engine the better.

Not to dissuade you from your experiment Petroldave, but I'm pretty sure that the Wynn's is going to do the square root of FA for your inlet bearing in mind the nature of the characteristic deposits seen in the photos so far...but,anyway, how will you know?

Looks like I'll have to get someone into my manifold at some stage in the near future and then, once clean, my inclination is towards (if the Titan Fuchs appears not to be up to the job) moving to RLI usage, venting to a catch can in conjunction with a methanol injection system, plumbed into the inlet somewhere (something the 2.0 TFSI boys already have available too)...the added advantage being I might get a bit more power too.



I'm looking forward to you pulling your intake again SilverRS4...

PS: Recent surgery means I'm sitting on my a** again with loads of time to investigate the properties of oil....

[P_G]

it would suprise me that a company like VAG would be able to produce an engine that is prone to failure in such tightly regulated markets now.

It would surprise me if a company like VAG produced a suspension system (repeatedly) that was prone to failure in such tightly regulated markets - oh hang on, they have!

Seriously, I 100% believe there is something in this.

While an engine may take 100,000+ miles to actually break, would you be happy if the performance of the car constantly fell away until it blew? This could well be a contributing factor in why RS4's constantly fail to make claimed performance figures in the rolling roads.

The RS4 is sold as a 50k+ performance car so deterating performance (if proved) is totally unexceptable imho.

Our American friends have had good success in playing with the inlet manifold, but it’s just occurred to me a large chunk of the success could be because you simply cleaned the valves up? (Anto/Silver can you confirm?)

Looking at the pics in this thread, performance must be affected!

It depends to what lengths you want to go to avoid this but as my engine is about to be properly cleaned out I will do my best to avoid it gunking up again. I hope to be able to shed more light on the outcome soon

Of course, this is assuming it is gunked up inside but does anyone want to bet against it? (It’s a 56 plate with 18k on the clock for those contemplating..)

Rob, I'm not doubting there is something in this discussion and obviously there will be an affect on performance of a car with cleaned inerts as opposed to clogged up ones. The question I was trying to pose and perhaps did not make a good job of it was that there are, for non enthusiasts and proficient mechanics, some extreme lengths being taken here to improve performance and ultimately what is the cost to benefit ratio and would it break your car if you didn't do it? Even if I take it to a VAG specialist the cost to do this work will no doubt be pricey. Polishing and porting again is not cheap and for what?

I don't want to get back on to the r/r discussion because it appears that all Audis with the new power distribution bias whether 60/40 or 70/30 do not produce what they are supposed to so r/r results are likely more to do with electronically controlled power distribution than actual outright power and as discussed r/r are a very loose and ambiguous (prone to interpretation and conjuring) measure of what our cars can do.

My car is now on 43k miles and if I take it to the same r/r again and it produces the same power as when it did at 16k miles, is this all worth it becasue then I have had no deterioration?

If someone cleans there valves / manifolds etc, takes it to a r/r and it produces significantly more power then I am glad for them, but at the cost perhaps of say instead having a remap and a Milltek for example? And as for DRC, I still hold the view it is more to do with the stat of the UK road infrostructure or lack of it the then car itself, we may as well all go back to leaf springs!

[PetrolDave]

Got some of the Wynn's DIP3 liquid and aerosol from Camberley Auto Factors (nearest Wynn's distributor to me) at lunchtime, will try it when I get time.

The spray only takes 5 minutes, get on it man!

Someone mentioned an easy to access bung of some kind - any details?

[PetrolDave]

The RS4 is sold as a 50k+ performance car so deterating performance (if proved) is totally unexceptable imho.

Loss of performance as a mechanical system (e.g. an engine) is used and ages is part of the natural process - it has always happened and it always will happen since no material has a zero wear rate or an infinite life.

What is unacceptable is if the rate of loss of performance is greater than the "norm" or "average" (whatever that may be).

[PetrolDave]

Not to dissuade you from your experiment Petroldave, but I'm pretty sure that the Wynn's is going to do the square root of FA for your inlet bearing in mind the nature of the characteristic deposits seen in the photos so far...but,anyway, how will you know?

But if nobody tries nobody will know either way.

If I do notice a difference in performance then it will have been money well spent, if I don't then it didn't cost much so who cares?

[RI_RS4]

SR,

For RLI Biosyn, I'd recommend a 4K interval on the 1st introduction of the oil into the engine. It has incredible cleaning properties due to it's polar bio-esters and powerful detergent package. You'll want to drain after that interval and replace the oil filter to remove all the wear metals and contaminants from the previous oils. Afterwards, Biosyn can be safely run out to 7500 miles. 10K is possible, but only with oil analysis to monitor it's progress.

For Fuchs I'd want an oil sample at 3500 miles, to see how it's performing. I'm not sure about the 5W30 version. The 0W20 version of Fuchs Titan GT1 is based on very advanced ester technology. Although the 5W30 does not hold back dilution, because of its' lower viscosity, it might very clean things up. But I'm only guessing.