ImUrOBGYN Posted January 21, 2016 Report Share Posted January 21, 2016 I've heard and seen quite a bit about this issue. For those who have direct injection engines, what has been your experience? Turbos seem to fair even worse. Here's an example of what I'm referring to: Ignore the actual subject content, or don't, I'm only using this vid for the valve pics. (EDIT***Forgot you cannot embed with a specific start time. Begin the video @4:20, please or click the direct link.) Many manufacturers seem a bit quiet about this. Toyota got around this issue right off the bat about a decade ago by utilizing both port and direct injection with their original D-4S system. (Their system is also the only reason the FA20 in the FRS/BRZ makes its 100hp/L, as it's capable of more than just keeping the valves cleaner.) The only reason I can see other manu's not using something similar is for cost/complexity reasons. Quote Link to comment Share on other sites More sharing options...
Cordell Posted January 21, 2016 Report Share Posted January 21, 2016 Personally I think if manufacturers did a better job with the PCV system it would be much less of an issue. Of course all I'm really familiar with is GM, their position seems to be that it's going to happen so as a tech we have a ton of bullitens about putting chemicals into the intake to clean it up. Take the 1LE Camaro for example they actually used a catch can, although not direct injected they know PCV is an issue. I never thought about Toyota's direct/port injection hybrid system as having benefits of both. Makes lots of sense and aids in cleaning. Quote Link to comment Share on other sites More sharing options...
POS VETT Posted January 21, 2016 Report Share Posted January 21, 2016 I own/have owned three vehicles with GDI, unfortunately all of them have too low of a mileage to make intake valve deposit a problem. AFAIK, there are a few chemicals available over the counter to clean the deposit. There is also another cleaning method using media blasting (walnut shell) which is a lot more involved and expensive. Quote Link to comment Share on other sites More sharing options...
aussiek2000 Posted January 21, 2016 Report Share Posted January 21, 2016 I still prefer to run a catch can when possible, but the D4S system is a good way to deal with the issue. FWIW, I only run shell Nitro+ in both cars. Quote Link to comment Share on other sites More sharing options...
Littleguy Posted January 22, 2016 Report Share Posted January 22, 2016 I know I have seen the D4s used in Toyota trucks in South America for years now. Pretty cool tech. Quote Link to comment Share on other sites More sharing options...
Grudes Posted January 22, 2016 Report Share Posted January 22, 2016 From what I have seen it starts to be an issue around the 50K mark but there are a lot of products out there to help deal with it Quote Link to comment Share on other sites More sharing options...
ImUrOBGYN Posted January 23, 2016 Author Report Share Posted January 23, 2016 What products? Cuz if you think about it, adding it to your fuel won't help you. Quote Link to comment Share on other sites More sharing options...
Cordell Posted January 23, 2016 Report Share Posted January 23, 2016 What products? Cuz if you think about it, adding it to your fuel won't help you. The products GM would have us use get sucked in through a vacuum line, or you'd pull the intake and soak it depending on how bad it was. Quote Link to comment Share on other sites More sharing options...
unfunnyryan Posted January 23, 2016 Report Share Posted January 23, 2016 I'm pretty glad that my accord, for a 2011, has none of this new shit other than variable cylinder management. except I get relatively shit gas mileage Quote Link to comment Share on other sites More sharing options...
acklac7 Posted January 23, 2016 Report Share Posted January 23, 2016 Bring engine up to operating temp. Put car in second gear, bring up to 6000 rpm's. Hold at 6000 RPM's for about 3-5 seconds. Let off throttle, till about 2000 RPM's. Repeat 2-3 times. Carbon Cleaned. Driving like a Women is what causes 70% of Carbon Issues :thumbup: Quote Link to comment Share on other sites More sharing options...
acklac7 Posted January 23, 2016 Report Share Posted January 23, 2016 And before the "ZOMG you're going to blow your Engine" crowd comes in i've used this procedure (multiple times) on every last car i've owned, and they all absolutely loved it. Quote Link to comment Share on other sites More sharing options...
ImUrOBGYN Posted January 23, 2016 Author Report Share Posted January 23, 2016 The products GM would have us use get sucked in through a vacuum line, or you'd pull the intake and soak it depending on how bad it was. This seems to be basically what I'm hearing. Bring engine up to operating temp. Put car in second gear, bring up to 6000 rpm's. Hold at 6000 RPM's for about 3-5 seconds. Let off throttle, till about 2000 RPM's. Repeat 2-3 times. Carbon Cleaned. Driving like a Women is what causes 70% of Carbon Issues :thumbup: The Vibe is barely taking a breath at 6k rpm. Quote Link to comment Share on other sites More sharing options...
cdk 4219 Posted January 24, 2016 Report Share Posted January 24, 2016 Bring engine up to operating temp. Put car in second gear, bring up to 6000 rpm's. Hold at 6000 RPM's for about 3-5 seconds. Let off throttle, till about 2000 RPM's. Repeat 2-3 times. Carbon Cleaned. Driving like a Women is what causes 70% of Carbon Issues :thumbup: Not on a direct injection engine Toolio Quote Link to comment Share on other sites More sharing options...
acklac7 Posted January 24, 2016 Report Share Posted January 24, 2016 Not on a direct injection engine Toolio Afraid someone was going to say that. WOT-runs will still clean the valves/piston/combustion chamber, just not the injector, correct? Quote Link to comment Share on other sites More sharing options...
cdk 4219 Posted January 24, 2016 Report Share Posted January 24, 2016 The buildup on a direct injection engine is much larger, harder, and sticks to the valves with greater force than a port injection/ carburated engine. I have seen the buildup in the 7/16" range on a 1.25" valve. It either has to be cleaned manually, or with a some liquid introduced into the intake. The latter of the two being less effective, but obviously easier. Revving up the engine will either take small particles off or large iceberg chunks, that will not go through the valve, and may get stuck. Then there's the added weight of that buildup on a valve, opening and closing 3000 times per minute, hopefully the spring is up to the task of pulling the valve back in place before the piston takes the same real estate. As stated before in heavy buildup instances, manual scraping and vacuuming out is needed Quote Link to comment Share on other sites More sharing options...
schmuckingham Posted January 27, 2016 Report Share Posted January 27, 2016 I spray meth, clean as a whistle Quote Link to comment Share on other sites More sharing options...
ImUrOBGYN Posted January 27, 2016 Author Report Share Posted January 27, 2016 I spray meth, clean as a whistle You, sir, have a drug problem. I want to help you. Give me all your meths... Quote Link to comment Share on other sites More sharing options...
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