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Kiwi · 03-20-2012, 04:38 AM

Here are some more information regarding this matter about DI & Catchcans.
DI has been used in the GTI's engine and carbon deposits has been a well known issue among the owners.

Here it shows the amount of build up that can happen with DI. The owner disassembles the intake manifold to manually clean the valves.Take note of the how the valves look like after cleaning.
http://www.golfmkv.com/forums/showthread.php?t=103885

In this thread is the same car again but this time a VTA (vent to atmosphere) catchcan has been installed since he cleaned the valves. So everything from the PCV system is vented outside. Despite this, carbon deposits on the valves are still present.
http://www.golfmkv.com/forums/showthread.php?t=148048

Now I'm not here to say that catchcan's are totally useless in preventing carbon deposits, but maybe there are other reasons causing the deposits rather than the PCV system.
Personally I believe the inclusion of direct and port injectors in the Toyota system is ingenious. Even if the port injectors aren't always being used but it should still be quite effective at help reducing or preventing carbon buildup.
IIRC Toyota's patent on this dual injector system recently expired. So for the newer generation of Volkswagen engines being introduced now, they also has port and direct injectors. I think this means that Volkswagen also realizes the benefits of this system over the normal DI.

03-20-2012, 04:38 AM	#88
Kiwi Senior Member Join Date: Sep 2011 Drives: Volkswagen Golf GTI Location: Canada Posts: 151 Thanks: 1 Thanked 13 Times in 9 Posts Mentioned: 1 Post(s) Tagged: 0 Thread(s)	Here are some more information regarding this matter about DI & Catchcans. DI has been used in the GTI's engine and carbon deposits has been a well known issue among the owners. Here it shows the amount of build up that can happen with DI. The owner disassembles the intake manifold to manually clean the valves.Take note of the how the valves look like after cleaning. http://www.golfmkv.com/forums/showthread.php?t=103885 In this thread is the same car again but this time a VTA (vent to atmosphere) catchcan has been installed since he cleaned the valves. So everything from the PCV system is vented outside. Despite this, carbon deposits on the valves are still present. http://www.golfmkv.com/forums/showthread.php?t=148048 Now I'm not here to say that catchcan's are totally useless in preventing carbon deposits, but maybe there are other reasons causing the deposits rather than the PCV system. Personally I believe the inclusion of direct and port injectors in the Toyota system is ingenious. Even if the port injectors aren't always being used but it should still be quite effective at help reducing or preventing carbon buildup. IIRC Toyota's patent on this dual injector system recently expired. So for the newer generation of Volkswagen engines being introduced now, they also has port and direct injectors. I think this means that Volkswagen also realizes the benefits of this system over the normal DI.