FSI Engines - Audi RS4 Engine Oil-Related Deposits

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I've been posting on Audi FSI engines for some time now, and have discussed my oil analysis and issues with FSI engine fuel dilution impact on wear and deposit formation. Well, we now have confirmation of the oil-induced deposit formation issues with FSI engines.

Here's a direct quote from an RS4 owner who is also a Mechanical Engineer.

Quote:
A little over a month ago, had the car in for CEL, misfires, etc. They found bad injectors, replaced them and the car runs fine now. They also found the buildup on the intake valves that been talked about here. I was able to briefly look at it while they were cleaning them, but wasn't really able to inspect them. Well, I took the manifold off myself this weekend because I was bored and felt like wrenching on my car. It obvious from the intake ports and intake manifold that there is quite a bit of oil vapor in the intake air stream. Which is typical, especially on high performance engines. There is a light oily film on the manifold port (and flaps) leading directly into the cylinder head as well as in the port itself. The closer you get to the valves, the film is more tacky and in some places, almost hard. But not like dry flakes. IMO, the oil vapor entrained in the air stream just clings to the valves and sticks because the valves are relatively hot. Its not "carbon" buildup due to combustion, its oil film buildup thats not effectively cleaned by fuel since the engine is direct injected, not port injected. The RS4 has an elaborate crankcase ventilation system equipped with a 3-stage venturi cyclone to help remove the oil particles. Obviously it doesn't separate all the oil out. I don't think some buildup would be out of the ordinary on these engines. The valve in the pic was the worst and its been roughly 800 miles since the dealer cleaned them.


Quote:
After my $70k car's performance went down the gutter (the first oil change after the break in), I dug into it. I do various data logs almost every day. I plot the info and try to notice certain trends. After a while, things become clear but after you see your intake valves crudded up beyond belief and then in bad shape again only 800 miles later, it becomes obvious. The volatized oil creates buildup, which constantly breaks apart, which enters the combustion chamber, then adheres to injectors, which disrupts flow patterns and/or causes injector damage, which leads to poor economy and performance and fuel leakage into the chamber, that leads to cold start misfires and damaged coils. The buildup also drastically affects airflow into the engine. Dealers are good at replacing the coils, but bad at persisting to find what the root cause is. Its so ironic that the RS4 community thinks that my car is an exception just because I took the time to unveil an obvious problem. I would bet that 80% of them are having the same issues. Its really a shame, because the 4.2 FSI is going to get a bad wrap when its truly a masterpiece. I ordered 5gal of the RLI 5W40 and will be monitoring the intake valve buildup since I have no problem taking my manifold off to see what's going on.


IMO fuel dilution is the root cause for increased volatization and breakdown of the oil. 10 year oil Audi/VW formulations, designed to deal with engine sludge, do not stand up to fuel breakdown and end up as deposits on the valves, combustion chamber and injectors.

a-intakevalve.jpg
 
Wouldn't it also be smart to trap the oil before it gets to the valves etc. using something like this?
catchcancopy.jpg


This is for the 2.0l FSI, brand is BSH, from their website:

Details:
Designed with simplicity of install in mind the BSH Bulletproof PCV Stage 2 kit takes our already successful PCV program one step further. Manufactured here in the US, the CNC machined BSH Bulletproof PCV Stage 2 fixes all the major problems associated with the prone to failure PCV system and adds a true catch can to capture all oil vapors that would otherwise make their way back into the engine. This package is the ideal performance solution for those who want the most out of their tuned 2.0T!

This kit comes complete with every hose, bracket, nut, and bolt needed to install!

Function:
Increase your engines performance and longevity with a BSH catch can system. Our catch can catches oil vapors and still fully meets emission requirements. Internally the catch can has chamber that forces oil to separate from the air as it passes through. This oil then falls into the gut of the can and can be drained at your next oil change.

For the best performance possible you do not want this oil making its way back into your engine! Short term oil vapors being ingested result in a greater chance for pre ignition, over time however this oil will cake the intake valves shortening the life of the engine. Outside of oil, the can will also catch water and fuel. Take a look at the detailed pic section to see what muck is getting ingested into your engine! Stop this once and for all!
 
Thanks for sharing. How is the RLI oils holding up for other members? Is it reducing any of the deposits? It's my understanding that the bio syn oils have exceptional cleaning capability.
 
saaber1

There is already a cyclonic oil separator in these engines that is a bit more advanced than a catch can. There is nothing more efficient in removing oil from the PVC system that that. But, a cyclonic separator cannot remove volitile oil components that remains in the vapor stage. Fuel dilution can drive flashpoint down in the mid 200F range in these engines, which is the operating oil temperature.

42FSIpg9.jpg
 
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What is the best plan for preventing this? I think it requires attention to oil choice, oil change interval, and fuel additives.

The first two are simple: superior oils and sufficiently short OCIs...whatever those are.

It is the latter that is less clear to me. What additives should be used and at what treat rates? I'm quite sure a constant dosing would be best rather than letting buildup happen then shock-dosing it to clean it up. Some candidate additives are: FP60, RLI's Fuel Additive, Techron or similar products, BG44K, and ester-based two-cycle oil like Maxima K2.

I am experimenting with Maxima K2 in my guinea pig, the VW 1.8T, using it at 750:1 and 500:1 ratios. It is not direct-injected engine but I think it can still provide insight as to relative effectiveness of various fuel additives. It is too early to tell if it will clean the carbon from the piston tops but it certainly did leave the carbon "wet" and able to be easily scraped off.

Prior to using the two-cycle oil, I tried many uses of FP60 and it did NOT clean the carbon from the piston tops. The only hope for it would be for me to increase the treat rate above what's recommended.

I just got done running BG44K in one tankful and I will pull the spark plugs any day now to see what it did. I'll report back what I find.
 
No one running Biosyn is reporting any misfires or loss in power. This particular owner just bought a 5 gallon pale of Biosyn 5W40 and will be monitoring it's progress by pulling the intake manifold and performing visual inspection of the valves. We'll know after a month on how well it does.
 
For those who like to read patents, Lubrizol has done some interesting work on creating oil formulations specifically designed to reduce intake valve deposits. In the case of the VW 4 cylinder FSI engine, they show around 40% improvement. One of the key features of the patent is the combination of PAO and synthetic Esters in the oil, with a high percentage of Esters. The one thing they could not patent was RLI's Bio-Ester technology, which was already patented, and uses PAO, bio-ester blends and stabilizers in their formulations.



Method for Reducing Intake Valve Deposits in a Direct Injection Engine
 
Rl_RS4, are you saying that the cleaning which takes place is from the oil vapors going through the intake valves and combustion chamber? If so, is Biosyn effective because it reduces volatility or because of the cleaning effectiveness of the volatilized oil?

Is the oil volatility inevitable with any oil in this engine and the most important factor in terms of preventing deposits to the intake valves, injectors, etc. the oil's ability to clean?

Very cool info. posted above BTW, thanks!
 
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Originally Posted By: JAG
What is the best plan for preventing this? I think it requires attention to oil choice, oil change interval, and fuel additives.

The first two are simple: superior oils and sufficiently short OCIs...whatever those are.

It is the latter that is less clear to me. What additives should be used and at what treat rates? I'm quite sure a constant dosing would be best rather than letting buildup happen then shock-dosing it to clean it up. Some candidate additives are: FP60, RLI's Fuel Additive, Techron or similar products, BG44K, and ester-based two-cycle oil like Maxima K2.

I am experimenting with Maxima K2 in my guinea pig, the VW 1.8T, using it at 750:1 and 500:1 ratios. It is not direct-injected engine but I think it can still provide insight as to relative effectiveness of various fuel additives. It is too early to tell if it will clean the carbon from the piston tops but it certainly did leave the carbon "wet" and able to be easily scraped off.

Prior to using the two-cycle oil, I tried many uses of FP60 and it did NOT clean the carbon from the piston tops. The only hope for it would be for me to increase the treat rate above what's recommended.

I just got done running BG44K in one tankful and I will pull the spark plugs any day now to see what it did. I'll report back what I find.


best plan for preventing this is to vent crankcase out to atmosphere rather then back into intake. I did this on my S4 and no more oil deposits on the intake side(intercoolers, bypass valves and IM)

second option is to seafoam/water your car twice a year to get rid of the deposits..

first option gets my vote since it eliminates root cause of the problem.
 
Originally Posted By: zoomzoom
best plan for preventing this is to vent crankcase out to atmosphere rather then back into intake. I did this on my S4 and no more oil deposits on the intake side(intercoolers, bypass valves and IM)

second option is to seafoam/water your car twice a year to get rid of the deposits.
Thanks. Yeah that will work but isn't the loss of having some vacuum in the crankcase (due to PCV suction) a concern that fuel dilution will significantly increase? I've often wanted to install an electric "wet" pump to pull a vacuum out of the crankcase and get rid of the PCV system.
 
How would you vent to the atm when the PCV is a closed system? Would you just have to run a secondary pump to keep the crankcase under vacuum. Also I will be interested to see how RLI helps with lower deposits.
 
Originally Posted By: agpatel
How would you vent to the atm when the PCV is a closed system? Would you just have to run a secondary pump to keep the crankcase under vacuum. Also I will be interested to see how RLI helps with lower deposits.


no need to keep crankcase in vacuum.crankcase with atmospheric pressure is just fine..

you just need to cap of source of crankcase vacuum so you don't have vacuum leak.
 
Originally Posted By: SubLGT
How are Audi service techs cleaning the valves?

This is from dsire on vwvortex. Looks like a good method to me.

basketballneedle.jpg


Remove the intake air temp sensor using a t30 torx.

1/4" fuel line (the heavy duty stuff with 1/2" OD) fits perfectly into the intake air sensor port, which is centrally located directly above the throttle body. This will distribute evenly to all four cylinders.

A basketball needle fits perfectly inside and provides enough restriction that you can run without codes. It also will meter the valve cleaner at a rate of approx. 100-150 ml/min, which will prevent hydrolocking the engine. (calcs based on a 0.5 to 0.6 mm diameter opening in the needle, and an intake vacuum of 20" of hg (approx. -10 psig)

Leave the intake air sensor electrically connected so you do not get any faults. It will still sense the air temp, albeit a little off.

Do not goose the throttle with it connected. You want the intake under vacuum, and not boost pressure.

The active ingredient in the valve cleaner is naptha. The good German Ventil Sauber (valve cleaner) is about twice the concentration as the domestic Seafoam, but you get twice as much Seafoam for your buck.

Use a longer fuel line than I have shown so you can dip into the can.
 
Here is a photo posted by vwtechhouston on vw vortex. It is the intake valves of vw eos with only 22k miles. It appears reducing oil/other-derived deposits in the pcv system is a big deal in direct injection engines.

valve2pn3.gif
 
Has this problem been an issue in Europe? If it hasn't, perhaps it relates to the North American market's lower standard of using 502.00 oil.

Are there reports of this problem while running a 504.00 oil? Just curious, as I haven't had any issue with my 2.0T FSI and I'm running 504.00 certified Mobil-1 5W-30 ESP.

Cheers
 
Originally Posted By: rshunter
Has this problem been an issue in Europe?


One of my German friends told me recently this joke:

In Germany we change the oil. In the US they change engines.


LOL.gif
 
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