Secondary air alternative

Chester Instructor California Posted   Latest   Edited  
Resolved
Tooling
2012 Audi S5 3.0L 7-spd (S Tronic)
P0491 — AIR System Insufficient Flow Bank 1
P0492 — AIR System Insufficient Flow Bank 2
MIL On

Hello, Does anybody have an alternative to the high pressure washer set up that Audi recommends? I’ve heard of sources in Europe that use a different (dry)method, but have not been able to find any. I guess I will have to just pull the exhaust manifolds….

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Charles Technician
California
Charles
 

Pulling the manifolds will not help. The restricted ports are in the cylinder head facing towards the intake side off the air passage running from the combi valves on the back of heads. You need a 4000 PSI pressure washer and the special attachment kit to get in there. And even then you should use an endoscope to double, triple, check the ports. Some carbon gets packed in and hardens to the…

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Michael Owner/Technician
California
Michael
 

This is a thorough explanation Charles. I purchased the tooling from Audi and after one use I would be ok if it was my last time, not a fun repair but made for a happy customer. The tooling from audi is poor aswell in my opinion, I fought it the first couple goes because their ruler markings are not straight and makes for guess work.

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Charles Technician
California
Charles
 

I will admit it does feel cheap. Best way to use that tool is to use those markings as suggestions of where you should be. Instead of using the guide holders I move the mount to the ruler marking so I have an idea of where the port is and what direction it is face and then just move it back and forth by hand and listen for change in the water pressure. Once I know I'm on it I spend about 5…

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Don Diagnostician
Tennessee
Don
   

Hi Chester, I don't know of a method other than pressure-washing, but I made my own pressure-washing wand for decarbonizing Audi engines from a few bits from the hardware store. I used a section of standard 3/8" O.D. copper pipe and cobbled together plumbing fittings that would connect to my pressure washer at one end, then crimped the other end so it would spray from the tip, and drilled four…

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Michael Diagnostician
California
Michael
 

I used carbon cleaner sprayed it in to soak and stuck a wand and used shop air I could feel it unplug as I stuck it in. Car did not return.

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Kirk Owner/Technician
California
Kirk
 

I did a few using drill bits and it works Ok. Also, not messy at all.

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Dan Owner/Technician
Texas
Dan
 

… I often wonder if the method I use for de-coking weed whacker mufflers would work on things like this (and also nasty valve stem deposits on GDI's… Yet untried) where as I set the carbon ablaze (slightly) with my oxy/Acetylene torch and turn off the Acetylene and hit it with short bursts of the pure oxygen…keeping the glow going (important)… and in doing so, the carbon will “self consume” and…

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Kevin Educator
California
Kevin
 

I like the idea. I have some reservations, especially until tested. But, I like the idea.

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Dan Owner/Technician
Texas
Dan
 

… I would like to test it on a filthy core GDI head… If valves are closed and seated (like they would have to be for media blasting) I think it would work BETTER than media BLASTING and be a heck of a lot cleaner with just ash as an end product… the discretion would be in the amount of oxygen fed to the glowing carbon down in the port , once it is set to glowing(should be very visible)… I just…

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Don Diagnostician
Tennessee
Don
   

It's a very interesting idea, but you would have to take into account that the melting point of many aluminum alloys is only about 1,200 degrees Fahrenheit…. I don't know how hot carbon burns, but according to this article, if coal dust explodes, temperatures can reach 2,500 to 2,600 Centigrade (4,500 to 4,700 degrees Fahrenheit)! sciencedirect​.​com/topics/enginee…

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Dan Owner/Technician
Texas
Dan
   

… I don't think that this procedure would generate anywhere near those temps … as the amount of FUEL (the carbon) would be very small , and it would only react to the small amounts of oxygen fed to the “glow” (With discretion by the operator). … someone with a core PLEASE try it and see how it goes … Dan H . … Hobbs … South Texas …

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Dan Owner/Technician
Texas
Dan
 

… Nothing would be “exploding” … just the glowing ember, as it was consumed…I'll try to find a core to “test” on. … Hobbs.

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Antonio Owner/Technician
Ontario
Antonio
   

I have used a home made rig another shop made. Simple to make and effective. 26" 3/8 Fuel line, old school hard type better. Weld a power washer fitting to one end, block off the other end. Drill small hole about ¼ inch from blocked end, about same hole size found on the washer bits. Put 3 marks on the tube, at 2", 5.5" and 9¼, those will be the marks that will line up with holes in the head…

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Erik Diagnostician
Florida
Erik
 

Easiest way is to get that tooling and the correct CFM pressure washer or it’s the more time and parts removal with 36in drill bits and such. Surprisingly almost every 3.0L Supercharged version of this engine almost always has these codes with a new SAI pump but no cleaning. Lol. eBay has them slightly cheaper than the dealer.

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Chester Instructor
California
Chester Resolution
 

Hello, so we just pulled exhaust manifolds and everything clean up to the valve therefore has run the monitor. Thanks

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