What would you say is better, induction service or walnut blast? I’m guessing walnut is a lot more expensive because they actually have to take apart the intake manifold right?
Just got two prices for induction service out here in California. One was $287 with no guarantee it will solve the problem (and won’t put that $287 toward a walnut blast service if it does not work), and the second was $350, again with no guarantee and that one doesn’t have the equipment for walnut blast.
Can you find someone with a fiber optic scope to look at a few valves?
What makes you think that?
Just based on internet research and what my usual mobile mechanic has told me. Plus the spark plugs were just replaced recently and that didn’t change anything. I’m definitely not a car expert though, do you have other ideas what could be causing the misfire issue? It happens more while idling and at low speeds, and decreases a bit as the engine warms up.
Also can anyone tell me how much damage I might be causing by driving the car while this issue persists?
Ooo that’s a good idea. Not sure I know anyone in the area who has one but I can check
Does your 2009 VW GTI use direct injection Cody?
Yep, I believe that it does. No port injection I’m pretty sure
I don’t work on VWs but I have worked on a number of direct injection Lexus engines that had misfires due to carbon build-up on the back side of the intake valves. What troubles the customer most is that when a misfire is detected, usually intermittent, the computer shuts off that injector resulting in a dead cylinder and poor acceleration until the ignition is cycled.
There is sometimes more than 50% air flow blockage, cleaning the intake valves will restore the engine’s performance.
What would you recommend for cleaning them off assuming the blockage is bad? Walnut blast or do you think an induction service will take care of it? Or clean it the valves hand with a brush?
Your local professional will have their preferred procedure. We used a chemical soak for several hours that paid 4 hours labor but since 2013 the factory has been paying to replace the pistons and clean the valves by hand (removed).
Gotcha. The problem is there are many local professionals and they all recommend something different
A 2009 direct injection VW GTI with a carbon build up problem on the valves is probably going to be a tough nut to crack. The engineers hadn’t figured out how to prevent that for many of the earlier direct injection engines, but supposedly this has been solved w/newer designs. IIn order to get more help, suggest that you post this to a new thread Cody. Click “maintenance/repairs” above, left, then “new topic”, above, right.
Try posting this on VW forums, like VWVortex and TheSamba. Others have dealt with this, they’ll probably be happy to tell you how.
I think I’m just going to have the manifold taken off and walnut blasted tomorrow. You think that’s a bad idea?
BMW has been using the walnut cleaning process for thirty years, the walnut shell particles won’t harm the cylinder walls if they fall into the cylinders.
Lexus used a chemical treatment on the 3GR and 4GR engines. The valves were soaked with GM top engine cleaner, started, oil changed, driven ten miles and oil changed again. The walnut cleaning process would not require two oil changes.
I’d prefer the walnut cleaning. If there are significant deposits the chemical cleaning would move them ‘downstream’, through the turbo into the cat. Not what I’d want.
There is usually more then one solution.
Fuel induction services are not a scam nor are they useless an offer no benefit. You take any direct fuel injected vehicle for instance and don’t do it and you will soon find out why the engine is loud as hell, poor fuel economy and performance and I have also seen pre detonation and engine failure. I have personally had to take intakes off cars and heads to clean the valves by hand because customer thought it was never needed and ended up costing thousands. Direct injection you no longer get the fuel passing over the intake valve to help clean it. So now deposit build up happens much sooner. At Hyundai we do it every 15k I’ve seen other manufacturers recommend every 10-12k. On mpfi and throttle body injection an the others where fuel passes over the back of the intake valve, yes they do stay cleaner an additives an good fuel help but still should be done every 30k. Look up how to do it yourself it’s homestly not that hard especially on a Honda 3.5. Then you will notice the improvement or use a scope through each spark plug before and after and watch the results.
That usually is what I’ve done on bmw and Audi’s they have a lot of carbon deposit issues and have had to remove heads by 60k to blast off the carbon deposits. So many ppl think adding a cleaner to my gas tank will do the trick… ya not on direct injection engines and even on mpi an Tbi an the others yea it helps but only to am extent. Running a cleaner through a vacuum line or through throttle body then letting it hot soak for 15-20 min and then driving it really is the best way other then removing the heads and cleaning the intake valves and piston tops yourself