Valve Stem Carbon Build-up from Oil in DI Engines

[Mad_Hatter]

Originally Posted by UG_Passat
over 100,000 miles on my current car, using high SA oil, and hasn't started to misfire, which is usually a symptom of excessive Intake Valve buildup.

The only change from my previous car, religious use of additional fuel injector cleaner with every tank (1 oz of Renewable Lube fuel injector cleaner).

That's only for excessive carbon on the piston tops, which can alter compression amongst other things (like hot spots and pre-ignition). The effects (symptoms) of excessive carbon buildup on the valves are different.

 

[Mad_Hatter]

Originally Posted by thunderchild
Originally Posted by UG_Passat
over 100,000 miles on my current car, using high SA oil, and hasn't started to misfire, which is usually a symptom of excessive Intake Valve buildup.

The only change from my previous car, religious use of additional fuel injector cleaner with every tank (1 oz of Renewable Lube fuel injector cleaner).

I have 142,4** on mine and she runs great so far. Will a good fuel injector cleaner help with this issue?

Do you have a port injected engine?..if so, than a system cleaner (not injector cleaner) from Gumout or similar will help.

 

[buster]

Modern Engine Oil never fully explained how it works. They did a terrible job marketing this oil. The price of it tells me there is something unique about it, but I still don't understand how it works. It is odd to me that the Noack is higher than their regular FS oil and they don't provide you with the SA level, which we know is a source of IVDs.

Mobil as usual was way ahead of Vavoline on this issue.

 

[Mad_Hatter]

Originally Posted by buster
Modern Engine Oil never fully explained how it works. They did a terrible job marketing this oil. The price of it tells me there is something unique about it, but I still don't understand how it works. It is odd to me that the Noack is higher than their regular FS oil and they don't provide you with the SA level, which we know is a source of IVDs.

Mobil as usual was way ahead of Vavoline on this issue.

+1

 

[UG_Passat]

Originally Posted by Mad_Hatter
Originally Posted by UG_Passat
over 100,000 miles on my current car, using high SA oil, and hasn't started to misfire, which is usually a symptom of excessive Intake Valve buildup.

The only change from my previous car, religious use of additional fuel injector cleaner with every tank (1 oz of Renewable Lube fuel injector cleaner).

That's only for excessive carbon on the piston tops, which can alter compression amongst other things (like hot spots and pre-ignition). The effects (symptoms) of excessive carbon buildup on the valves are different.


On my 08 Passat, with FSI-turbo engine, when the IVD was too much, the most common symptom was multiple misfires.

 

[PimTac]

Originally Posted by buster
Modern Engine Oil never fully explained how it works. They did a terrible job marketing this oil. The price of it tells me there is something unique about it, but I still don't understand how it works. It is odd to me that the Noack is higher than their regular FS oil and they don't provide you with the SA level, which we know is a source of IVDs.

Mobil as usual was way ahead of Vavoline on this issue.



Dittos.

 

[LeoStrop]

Originally Posted by paoester
Originally Posted by LeoStrop
Originally Posted by paoester
This will make you want to use a low saps oil!
But will that eliminate the problem? I'm not so sure...
Great question. I suspect its caused by higher saps levels, based on some engineering statements made over the years. You're right we can't be sure.

It is speculated that Valvoline is putting some of its patented "Valvoline Premium Blue Restore" low aniline point oil patented chemicals in Valvoline Modern Engine oil. Although their Restore product mostly affects the ringlands on engines.
https://www.bobistheoilguy.com/foru...arbon-cleaning-valvoline-premium-restore
It dissolves carbon: https://www.bobistheoilguy.com/forums/ubbthreads.php/topics/4995896/1

Several years ago Lubrizol thought valve deposits in DI engines were at least partly caused by ash combined with carbon, getting sticky. I'm not sure if they were ever right about it. They might be.


Although the oil will help alleviate the problem, it will not get rid of it completely. Because, isn't low saps oil already being recommended for those cars?
The Valvoline PBR is on another league, maybe that can help a lot, but some would have to use it all the time to really work and let things clean.

Maybe a timed dosage of some sort of intake cleaner can be much more effective, but maybe the only right way to do it is taking the manifold out and do a blasting with the valves closed.

The only severe problem i have heard happening, is the valves getting stuck after a long period if the car is not being used.

 

[BLND1]

Originally Posted by buster
Modern Engine Oil never fully explained how it works. They did a terrible job marketing this oil. The price of it tells me there is something unique about it, but I still don't understand how it works. It is odd to me that the Noack is higher than their regular FS oil and they don't provide you with the SA level, which we know is a source of IVDs.

Mobil as usual was way ahead of Vavoline on this issue.


I think that as a whole, this site has obsessed over NOACK while marginalizing other potential contributing factors to deposit formation.

More than one way to skin a cat and all.

 

[BMWTurboDzl]

Originally Posted by thunderchild
I have a BMW X5 3.0 si. I have the DI engine. What is the best way to keep the carbon buildup off the top of the valves? I am looking into the Seafoam treatment. Does anyone have any ideas on how to maintain this?


Answer: You don't have DI. You have the BMW N52 with port injection and consequently don't have to worry about it. The first DI BMW engine sold in the US was the N54 (Turbo I6).

 

[thunderchild]

Originally Posted by BMWTurboDzl
Originally Posted by thunderchild
I have a BMW X5 3.0 si. I have the DI engine. What is the best way to keep the carbon buildup off the top of the valves? I am looking into the Seafoam treatment. Does anyone have any ideas on how to maintain this?


Answer: You don't have DI. You have the BMW N52 with port injection and consequently don't have to worry about it. The first DI BMW engine sold in the US was the N54 (Turbo I6).

Thank you this was the answer I needed for my truck. No DI. That is a relief.

 

[Luftmasse]

Low sap vs Noack, which has a stronger effect?

Valvoline has high Noack number, 12% on the 0w oils.

 

[buster]

Sulfated Ash is more important than Noack for reducing IVDs IMO.

 

[Mad_Hatter]

Originally Posted by buster
Sulfated Ash is more important than Noack for reducing IVDs IMO.

And i don't imagine leaking valve seals helps this problem either. All the more reason to stay on top of your changes to minimize the potential for the seals going bad.

 

[paoester]

What's in Valvoline Modern Engine? Could be they are going more ashless (ironic from Ashland...) by using something similar to the oil released last week https://www.ccjdigital.com/chevron-debuts-lower-ash-diesel-engine-oil/ which has SA = 0.4%, a CK-4 oil.

Shell jumped on the "low-ash / cleaner intake ports" bandwagon with "Shell Rotella T1 provides low ash content for clean intake ports..." in their diesel oil product description.

Not sure what to make of all the clues. Still could be some kind of cleaner-solvent-chemistry like Valvolne Premium Blue Restore.

 

[gathermewool]

I read on another Subaru site that, in our FXT's (and WRX's, and supposedly all of their DI/DIT engines), they mitigate buildup by design. They supposedly designed some sort of baffling (torturous path) in the crank-case-to-PVC plumbing, similar, I guess, to an internal catch can. I'm sorry that I don't remember more and I don't have references; just memory from reading it several years ago.

It makes sense that manufacturers could design IVD mitigation strategies, including the above, as well as internal EGR, with variable valve timing now being common on both intake and exhaust valves. I don't know how it would work, exactly, but there's got to be a way to allow some of the DI fuel to be forced back into the intake just enough to provide at least some minimal level of cleaning. Does this make sense? Is this already a real thing?

Great conversation, btw. I'm enjoying reading the comments!

 

[benjy]

engines vary and its when not if you will have issues with DI only! of course theres a few newer vehicles using both or as i do NO direct injection period. 200 thou trouble free miles on my port injected 1.8t vw at trade on a 1.8t audi tt both 2001

 

[Luftmasse]

Originally Posted by buster
Sulfated Ash is more important than Noack for reducing IVDs IMO.


I believe for OTC oils, Mobil 1, would fit best in that category for 0w oils.

 

[Luftmasse]

Originally Posted by UG_Passat
over 100,000 miles on my current car, using high SA oil, and hasn't started to misfire, which is usually a symptom of excessive Intake Valve buildup.

The only change from my previous car, religious use of additional fuel injector cleaner with every tank (1 oz of Renewable Lube fuel injector cleaner).


Year, make and model?

On GDI engines only, fuel injector cleaner does Nothing to clean up the valves because the fuel injectors does not spray onto the valves...

 

[Luftmasse]

Originally Posted by gathermewool
I read on another Subaru site that, in our FXT's (and WRX's, and supposedly all of their DI/DIT engines), they mitigate buildup by design. They supposedly designed some sort of baffling (torturous path) in the crank-case-to-PVC plumbing, similar, I guess, to an internal catch can. I'm sorry that I don't remember more and I don't have references; just memory from reading it several years ago.

It makes sense that manufacturers could design IVD mitigation strategies, including the above, as well as internal EGR, with variable valve timing now being common on both intake and exhaust valves. I don't know how it would work, exactly, but there's got to be a way to allow some of the DI fuel to be forced back into the intake just enough to provide at least some minimal level of cleaning. Does this make sense? Is this already a real thing?

Great conversation, btw. I'm enjoying reading the comments!


Vehicles with EGR system also causes carbon build-up in the intake system also.

 

[Mad_Hatter]

Originally Posted by gathermewool
I read on another Subaru site that, in our FXT's (and WRX's, and supposedly all of their DI/DIT engines), they mitigate buildup by design. They supposedly designed some sort of baffling (torturous path) in the crank-case-to-PVC plumbing, similar, I guess, to an internal catch can. I'm sorry that I don't remember more and I don't have references; just memory from reading it several years ago.

It makes sense that manufacturers could design IVD mitigation strategies, including the above, as well as internal EGR, with variable valve timing now being common on both intake and exhaust valves. I don't know how it would work, exactly, but there's got to be a way to allow some of the DI fuel to be forced back into the intake just enough to provide at least some minimal level of cleaning. Does this make sense? Is this already a real thing?

Great conversation, btw. I'm enjoying reading the comments!

Someone a while ago suggested that vvt allowed fuel spray to travel back up into the intake but I couldn't nail down during what stroke, in a 4 stroke engine, this phenomena could occur???