GDI Intake Valve Cleaning

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2015 Audi A3 2.0T, 97K miles.
EA888 Gen 3 engine

Mostly highway driving and the owner has a heavy foot.

Oil changes are done every 10k using synthetic and generic filters, but I doubt he uses an Audi spec oil.

No misfires, but it did have a somewhat rough idle at cold start up.

Before - Cyl 1:
F1B37407-8BD6-4276-AF5F-9E2F7C31F395.jpeg

Unfortunately I forgot to take pictures of the other cylinders before the cleaning was performed. Cylinders 1 and 2 were much cleaner than 3 and 4.

After:

Cylinder 1:
38E6037B-E418-4B0F-9321-294A6C28B007.jpeg

Cylinder 2:
CD22E200-B246-48FB-A0EC-235ADA1FCCBB.jpeg

Cylinder 3:
85F7123B-D4FC-4EFB-B0E4-D1C718EBD358.jpeg

Cylinder 4:
11C2F33F-2E39-4F32-94E0-9CD7515ADB11.jpeg

All of the carbon was soft and sticky. I think solvent may have been almost as effective as walnut blasting.

I gave cylinders 1 and 2 a follow-up cleaning after taking those pictures. I found some leftover carbon on the backside of the stem.

The process is fairly quick once the intake manifold is removed. Set the cylinder to TDC and make sure the intake valves are closed. Using a pick, carefully “pull off” the sticky pieces of carbon deposit from the back side of the valve stem and the edge of the valve. It takes well under 30 seconds of blasting, per valve, to remove most of the debris. Then, I blow out the remaining media with shop air, scrape off any large or stubborn bits that were missed, and follow up with another quick blast (few seconds). At least for this vehicle, that approach got the intakes valves near perfect.

I bought this machine for the job:

FBBC905C-B552-4FD2-8728-4C8DEF1755A0.jpeg

This is the factory BMW tool for intake valve cleaning. I have never used the HF equivalent, but this BMW tool works extremely well. The bad news is that it consumes an absurd amount of media. I went thru almost 50 lbs of the HF Walnut media (fine grade). And I only blasted each cylinder for 30-45 seconds total.

Cleaning the intake valves does appear to have resolved the rough idle and has greatly improved the throttle response. I recognize that these are subjective improvements, not objective. Although it was nice to do, cleaning the valves was not entirely necessary.
 
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Not really. Water pump/t-stat leak often, injectors leak, piston ring lands fail catastrophically and the cam chain still stretches.
Surprising to hear that because I haven't seen many places talking about the gen3 being particularly problematic. Gen1/2 and maybe early gen3, but not much after that. Especially regarding the piston ring lands failing. LSPI maybe? I'm in the process of trying to convince my parents to dump a high mileage Traverse before the timing chains fail for an Atlas with the 2.0T actually.
 

The Critic

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Surprising to hear that because I haven't seen many places talking about the gen3 being particularly problematic. Gen1/2 and maybe early gen3, but not much after that. Especially regarding the piston ring lands failing. LSPI maybe?
The piston issue is really bad on the 15/16 A3’s and it also affects the S3 and GTI’s to a degree.
 
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The piston issue is really bad on the 15/16 A3’s and it also affects the S3 and GTI’s to a degree.
I also thought the water pump/t-stat issues were on the earlier productions too. I keep an eye on most of the VW forums and I haven't seen much about those failing on newer ones either
 
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Very nice!

Anyone ever see the ice blasting machine? I know it’s not exactly new, or cheap, but it looks pretty interesting. Instead of walnut shells it uses little ice pellets.
 
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Not really. Water pump/t-stat leak often, injectors leak, piston ring lands fail catastrophically and the cam chain still stretches.
The companies try to remove all the extras then can to save a few dollars at the operators expense later down the road.
 
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Could that have been mitigated by limiting OCI's to 5k miles, always using top tier gas, and adding Techron or Redline fuel system cleaner every 5k miles or is that pretty much what to expect at 100,000k miles ?
 
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Could that have been mitigated by limiting OCI's to 5k miles, always using top tier gas, and adding Techron or Redline fuel system cleaner every 5k miles or is that pretty much what to expect at 100,000k miles ?
I don't think that would mitigate the issue, especially the fuel system cleaners...they're not going to touch the back of those valves on a direct injection engine. Better oil, more frequent oil changes? I don't know, maybe could help a little tiny bit with the thought process that the older oil is thinning out even more and escaping up into the PCV system and collecting some in the intake. Or that the longer intervals are causing some ring wear and blow bye, excessive crank case pressure, forcing oil up into the manifold both through the PCV and into the breather. But in all honesty I think it's just a design flaw and was going to happen anyway.
 

The Critic

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Could that have been mitigated by limiting OCI's to 5k miles, always using top tier gas, and adding Techron or Redline fuel system cleaner every 5k miles or is that pretty much what to expect at 100,000k miles ?
Doubt it, but it is always possible. Maybe more frequent fuel system cleaning would have prevented injector failure, though. It needs injectors as well, so the intake is coming back off again in a few weeks.

@The Critic
You're thinking they used basic motor oil like SN etc?
Supposedly he installs whatever 5 qt oil + filter synthetic special is available from Autozone, and he doesn't know what an Audi spec is. So who knows...
 
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Could that have been mitigated by limiting OCI's to 5k miles, always using top tier gas, and adding Techron or Redline fuel system cleaner every 5k miles or is that pretty much what to expect at 100,000k miles ?

The degree of buildup heavily depends upon the PCV system and whether the automaker chose to implement a dual P/DI injection system. BMW for example figured it out over 10 years ago.
 

The Critic

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No and the degree of buildup heavily depends upon the PCV system employed by the automaker and whether they chose to implement a dual P/DI injection system.
PCV was closest to cyl #3/4 on this engine. Coincidentally, those cylinders were drastically more dirty than cyl #1/2.

Regardless, I don't think cleaning is always needed and chemical agitation may be sufficient.
 

The Critic

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The degree of buildup heavily depends upon the PCV system and whether the automaker chose to implement a dual P/DI injection system. BMW for example figured it out over 10 years ago.
I think BMW is doing what GM does, which is increasing valve overlap in hopes of getting some fuel mist onto the backside of the intake valves.

Overall there is some performance improvement to cleaning the intake valves, but until there is an actual misfire that is not related to other items, there isn't a need for this service.
 
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looks great + as i always todays cars are a "crap shoot" + early newer tech is usually worse until its sorted!! only own a PI car + truck + prolly will outlast me! eventually more will use both like VAG overseas as it works better for their tougher pollution standards!!
 
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I think BMW is doing what GM does, which is increasing valve overlap in hopes of getting some fuel mist onto the backside of the intake valves.

Overall there is some performance improvement to cleaning the intake valves, but until there is an actual misfire that is not related to other items, there isn't a need for this service.
I believe hyundai does this also on their DI engines.
 

TiGeo

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I also thought the water pump/t-stat issues were on the earlier productions too. I keep an eye on most of the VW forums and I haven't seen much about those failing on newer ones either
On the 1.8 and 2.0 EA888 gen 3 it's v. common with even the newer model years...a pandemic of sorts!
 
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