Intake manifold off with pics of intake valves with deposits.

GDI Tech · January 29, 2016

fondupot is correct. I wish it was helpful as it sure was in the old days of carbureted and port injection engines, but not with GDI.. The automakers have marketing deals with different fuel brands and oil brands (GM for years with Mobil, and BMW with Castrol, etc.) so that is a big part of recommendations. What E85 is good for is making power if you bump up boost and add more timing, etc.

Also, I have mentioned before, but there will always be a small amount of coking no matter what you do as there are some expended gasses that back swirl to emulate the EGR function and that brings in some contaminants to the back side of the valve, but the only way any fuel can help is if it is directly sprayed onto the valve to cool and clean it. Meth/water injection does show some reduction, but as it is only sprayed for brief times during boost, (for those with a system) it is only a small improvement.

Kerrslight · February 4, 2016

Fondupot, could this valve buildup cause the issue we've discussed before with the lunging acceleration and "plateau" while accelerating?

GDI Tech · February 5, 2016

The symptoms to start that are noticeable are hesitation off idle when accelerating, and as the deposits grow it becomes more noticeable. Then random misfires and some surging or chugging when cruising. Loss of power is hard to notice as it is gradual, but the difference after valve cleaning is dramatic. When the deposits are not severe, most is noticed at lower RPM's as the airflow disruption is most affecting when coming off idle, but will smooth out at higher RPM's due to the greater flow of incoming air. But as it builds even at higher RMP's it will be present.

What is occurring is the coking builds more severe the closest to the point of ingestion, and those cylinders are then getting less air entering yet the PCM is still commanding the injectors to deliver even fuel to each cylinder on that bank (the upstream O2 sensors measure the exhaust gasses as a whole from each bank). The cylinders farthest from this point of ingestion will develop deposits at a less severe rate, so they end up with more air than needed and run lean, while the worst are running too rich. This effects all drive-ability and the more they grow, the more disruption in airflow to the cylinder. The computer is still commanding an equal amount of fuel delivery from all injectors in that bank.

Hope that helps!

Kerrslight · February 5, 2016

The symptoms to start that are noticeable are hesitation off idle when accelerating, and as the deposits grow it becomes more noticeable. Then random misfires and some surging or chugging when cruising. Loss of power is hard to notice as it is gradual, but the difference after valve cleaning is dramatic. When the deposits are not severe, most is noticed at lower RPM's as the airflow disruption is most affecting when coming off idle, but will smooth out at higher RPM's due to the greater flow of incoming air. But as it builds even at higher RMP's it will be present.

What is occurring is the coking builds more severe the closest to the point of ingestion, and those cylinders are then getting less air entering yet the PCM is still commanding the injectors to deliver even fuel to each cylinder on that bank (the upstream O2 sensors measure the exhaust gasses as a whole from each bank). The cylinders farthest from this point of ingestion will develop deposits at a less severe rate, so they end up with more air than needed and run lean, while the worst are running too rich. This effects all drive-ability and the more they grow, the more disruption in airflow to the cylinder. The computer is still commanding an equal amount of fuel delivery from all injectors in that bank.

Hope that helps!

That definitely helps. That being said, my truck has 37,000 on the clock and I don't have a catch can installed, but I have tuned out AFM. How would I go about cleaning the valves? From what I understand I can get something at my local auto parts store and spray into the throttle body correct?

GDI Tech · February 5, 2016

This video shows pretty good, but I would add to first spray the valves your working on first with Amsoil/CRC/Seafoam valve cleaner and let soak to loosen, makes it much easier. Let soak for 15-20 minutes. Use a long shaft flat blade screw driver first to scrape loose the larger chunks before starting with the brushes. I use a shotgun cleaning kit as they have several sizes of brush ends and they are brass so last. Then suck out with shop vac and further blow out with compressed air. MAKE SURE the valve is completely closed when working on the cylinder you are going to first, and then tape off the rest. You do not want any debris falling into the cylinder. You will see 3-4 cylinders will have the valves closed at the same time so you can do several at one spot of the rotation. Make sure to pull coil plugs off so it does not fire when turning it over to get piston at TDC. It is best to put a socket on the crank pulley bolt and turn over that way.

Then ONLY install a system like fondupot.

Let me know if you need more help.

Takes about 3 hours for someone handy with tools.

Kerrslight · February 5, 2016

This video shows pretty good, but I would add to first spray the valves your working on first with Amsoil/CRC/Seafoam valve cleaner and let soak to loosen, makes it much easier. Let soak for 15-20 minutes. Use a long shaft flat blade screw driver first to scrape loose the larger chunks before starting with the brushes. I use a shotgun cleaning kit as they have several sizes of brush ends and they are brass so last. Then suck out with shop vac and further blow out with compressed air. MAKE SURE the valve is completely closed when working on the cylinder you are going to first, and then tape off the rest. You do not want any debris falling into the cylinder. You will see 3-4 cylinders will have the valves closed at the same time so you can do several at one spot of the rotation. Make sure to pull coil plugs off so it does not fire when turning it over to get piston at TDC. It is best to put a socket on the crank pulley bolt and turn over that way.

Then ONLY install a system like fondupot.

Let me know if you need more help.

Takes about 3 hours for someone handy with tools.

So there's nothing I can do without actually getting into the valves?

insanity213 · February 5, 2016

Which Elite Engineering catch cans are you using on the 5.3 afm engines? About to order one for my LS3 camaro but didn't see any options for the 07 - 13 afm trucks.

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GDI Tech · February 5, 2016

Always the E2-X as it is the most effective period. Get the dual valve so it evacuates at all times.

kerrslight, after you have say 10k miles on a GDI engine, the deposits become very hard and abrasive...like sand. So using a solvent based upper induction cleaning service (done while running) you risk damage as it breaks some of the deposits loose. None of those treatments clean more than 30% or so of the deposits either way though.

The manual cleaning is not hard to perform, if your not confidant, find someone near you to assist.

jrob56 · February 5, 2016

Which Elite Engineering catch cans are you using on the 5.3 afm engines? About to order one for my LS3 camaro but didn't see any options for the 07 - 13 afm trucks.

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07-13 trucks arent direct injection so I wouldnt even worry about it. If you want one though just get the basic can because its cheaper. You have fuel washing those valves all the time.

amfr · February 5, 2016

So after reading this thread I looked up the first article I could with gooogling seafoam. http://diysrc.com/how-to-seafoam-your-cars-engine-to-clean-and-dissolve-carbon-buildup/ obviously not the engine oil or gas part but the intake part had some interesting points I haven't seen in this thread. Has anyone tried this method or would anyone suggest that this not be tried?

sent from Florida beech

ToesonTheNose · February 6, 2016

GDI if I drive over to your shop you wanna clean my valves you installed my catch can last yr

tnchevy · February 6, 2016

I still have my doubts on how beneficial these things are and they, like most mods, will void your warranty if GM wants to press the issue. I guess I will keep going without one and see what happens down the road but I doubt it will be much. We have 4 silverado 5.3's in our fleet at work now and we put 35K+ miles on them a year so in a year to year and a half 2 of the trucks will have over 80k on them so we will see what happens with those.

GDI Tech · February 6, 2016

I still have my doubts on how beneficial these things are and they, like most mods, will void your warranty if GM wants to press the issue. I guess I will keep going without one and see what happens down the road but I doubt it will be much. We have 4 silverado 5.3's in our fleet at work now and we put 35K+ miles on them a year so in a year to year and a half 2 of the trucks will have over 80k on them so we will see what happens with those.

Never been a voided warranty for the Elite style cans as they cannot in any way cause any failure. They maintain a emissions compliant closed system and in the US, it would be against Federal law for a dealer to do so.

Here is another good article:

http://netwelding.com/catch_can.pdf

tnchevy, I would be willing to demonstrate on the fleet showing fuel consumption alone (average fleet owner see's 1-2 MPG improvement Port injection or GDI) and do a before dyno on your highest mileage truck and then clean the valves and do an after to prove if that helps. You would only need to get the truck to a shop of my choice. All else is no charge. That should do a ton to demonstrate how effective and how degrading the power/economy is over time.

On the SeaFoam, in the gas tank will do absolutely nothing as it never touches the backsides of the valves. That is throwing $ away. In the engine oil I would never dilute the oil with a solvent...risk damaging a rod or main bearing.

The engine running upper induction cleaning I have gone over in great detail as well. With an older port injection engine these are fine, with a GDI the deposits are not soft carbon, they are hard baked on crystalline abrasive as sand when broken loose, and even the solvent sellers state it only removes up to 30% or so. ONLY a manual cleaning with crushed walnut shell blasting or the solvent soak and brush method can clean them properly w/out damaging the engine. I do advise using it along with a good catchcan system every 10-15k miles as the amount of coking is so minor after installing and using a system like the Elite E2-X series it keeps them clean the life of the engine. But never use after say 10-15k miles w/out running a good system or the amount and hardness of the deposits may cause damage as it breaks loose.

And finally, for the pre 2014 engines that are port injection. You will have no deposits on the valves at all as the constant spray of detergent fuel keeps them clean and deposit free, but the oil and other compounds ingested via the PCV system cause increased detonation and the knock retard the computer commands when it detects this pulls timing, and if your not running optimum timing advance, power and fuel economy decrease. Then over time varnish builds up from this gunk in the ring lands and causes the rings to stick and not move freely, so that allows more blow-by and increased oil consumption.

Hope that clear some up!!

Silverado-Hareek · February 6, 2016

Never been a voided warranty for the Elite style cans as they cannot in any way cause any failure. They maintain a emissions compliant closed system and in the US, it would be against Federal law for a dealer to do so.

Here is another good article:

http://netwelding.com/catch_can.pdf

tnchevy, I would be willing to demonstrate on the fleet showing fuel consumption alone (average fleet owner see's 1-2 MPG improvement Port injection or GDI) and do a before dyno on your highest mileage truck and then clean the valves and do an after to prove if that helps. You would only need to get the truck to a shop of my choice. All else is no charge. That should do a ton to demonstrate how effective and how degrading the power/economy is over time.

On the SeaFoam, in the gas tank will do absolutely nothing as it never touches the backsides of the valves. That is throwing $ away. In the engine oil I would never dilute the oil with a solvent...risk damaging a rod or main bearing.

The engine running upper induction cleaning I have gone over in great detail as well. With an older port injection engine these are fine, with a GDI the deposits are not soft carbon, they are hard baked on crystalline abrasive as sand when broken loose, and even the solvent sellers state it only removes up to 30% or so. ONLY a manual cleaning with crushed walnut shell blasting or the solvent soak and brush method can clean them properly w/out damaging the engine. I do advise using it along with a good catchcan system every 10-15k miles as the amount of coking is so minor after installing and using a system like the Elite E2-X series it keeps them clean the life of the engine. But never use after say 10-15k miles w/out running a good system or the amount and hardness of the deposits may cause damage as it breaks loose.

And finally, for the pre 2014 engines that are port injection. You will have no deposits on the valves at all as the constant spray of detergent fuel keeps them clean and deposit free, but the oil and other compounds ingested via the PCV system cause increased detonation and the knock retard the computer commands when it detects this pulls timing, and if your not running optimum timing advance, power and fuel economy decrease. Then over time varnish builds up from this gunk in the ring lands and causes the rings to stick and not move freely, so that allows more blow-by and increased oil consumption.

Hope that clear some up!!

I have a question about doing an upper induction service later on in an engines life. My wife has a Hyundai Accent with a direct injection engine. We did a BG upper induction service around 45,000 miles and she does not have a catch can. After reading about the issue with the abrasive particles, do the particles cause damage at the time of the service only or do they get stuck in the cylinders and continually cause damage for the rest of the engine's life?

In other words, her car is running fine now. Am I ok to just avoid doing any more induction services or is there still potential for damage from the first service to occur and I need to be on the lookout for it?

Luckily with my truck I had the catch can put on at 11,000 miles and did a BG service at 14,500 so I should be ok to keep up with the services on the Silverado.

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HondaHawkGT · February 8, 2016

Here's a worthwhile link to check out. BG did a long term test on an EcoBoost Taurus. The PCV system Ford selected for the EcoBoost is prone to rapid carbon buildup/oil consumption. Pretty interesting.

https://www.bgprod.com/bgfueltest/