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At what point does it typically affect driveability etc? 100k ? 150k ?
On my n54 it was needed every 25-50k or it start to misfire, and the BG stuff was never sufficient, a walnut-blast is the only way to get rid of it.
Mileage is not a factor here !!..when I worked on jet engines back in the 70’s and 80’s we used walnut blasting as the preferred method to clean compressor blades !!
The going rhetoric here is that Chevy doesn't have DI valve deposit issues that ever need to be addressed. Could be that they positioned the injectors correctly so they hit the valves (a la porsche), could be that so few people take their corvettes out of their garage enough to actually develop a problem.
If you aren't misfiring (the feeling of misfire at idle is normal, BTW), and your mileage hasn't suddenly tanked, then you're just fine. Check after 80k+ miles.
The going rhetoric here is that Chevy doesn't have DI valve deposit issues that ever need to be addressed. Could be that they positioned the injectors correctly so they hit the valves (a la porsche), could be that so few people take their corvettes out of their garage enough to actually develop a problem.
If you aren't misfiring (the feeling of misfire at idle is normal, BTW), and your mileage hasn't suddenly tanked, then you're just fine. Check after 80k+ miles.
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GM does not have the DI issues that BMW or Volkswagen have ....... If its not broke ... Don't break it
Curious how we got to the conclusion that ‘GM does not have the DI issues that BMW or Volkswagen have’ — are there articles or videos I can watch to educate myself? I am curious about walnut blasting too and when it’s appropriate on a C7 Z06…
You can't position DI injectors to "hit the valves". The entire point of direct injection is that it injects fuel directly into the cylinder. Well after the valves.
Curious how we got to the conclusion that ‘GM does not have the DI issues that BMW or Volkswagen have’ — are there articles or videos I can watch to educate myself? I am curious about walnut blasting too and when it’s appropriate on a C7 Z06…
There are many posts with pictures proving that most GM DI motors do not have problems with carbon buildup . Occasionally you will see a picture of a bad one but I am a firm believer that they are the outlier and probably caused by other problems just think of how many GM di motors are on the street , don't you think we would have heard something by now . 😉 Heck my BMW did not make it to 30,000 before I had to get it walnut blasted Below is a picture of my valves at 37,000 miles ... I am not worried how about u ... Dave
You can't position DI injectors to "hit the valves". The entire point of direct injection is that it injects fuel directly into the cylinder. Well after the valves.
Now that I htink about it ... the N54 was particularly bad because of the way the PCV system worked. It sucked off the crankcase gases and fed it back through the intake right before the charge pipe. Also, there were ports from the intake tracts into the valve area to pressurize the PCV system (and had a nasty habit of blowing out valve cover gaskets), but when boost dropped it sucked more vapors in over the valves. I tried to mitigate it with a catch can and blocking those ports, but at 60k miles I realized I was spending more to repair it every month than a new car payment would be so i traded it.
I don't think the Corvettes does anything fancy/stupid like that, perhaps that's why there's so little buildup.
This was my BMW at 48k:  Now that I htink about it ... the N54 was particularly bad because of the way the PCV system worked. It sucked off the crankcase gases and fed it back through the intake right before the charge pipe. Also, there were ports from the intake tracts into the valve area to pressurize the PCV system (and had a nasty habit of blowing out valve cover gaskets), but when boost dropped it sucked more vapors in over the valves. I tried to mitigate it with a catch can and blocking those ports, but at 60k miles I realized I was spending more to repair it every month than a new car payment would be so i traded it. I don't think the Corvettes does anything fancy/stupid like that, perhaps that's why there's so little buildup.
yeah that's about how bad my BMW looked lol lol Dave
That design kinda defeats the purpose of DI as it is not an ideal position to spray the fuel , plus it would not provide nearly the cleaning that having fuel flow over the valve and stem from behind provides.
If it was that easy I am sure that the automakers would be doing it
Bottom line is , having a properly designed PVC like the LT motors system eliminates almost all the problems
The only reason I added a catch can recently was because I installed a procharger, having a blower changes things a bit and I did feel the need to add the can but so far I only have a ounce or two of oil vapor condensing in the can .
Curious how we got to the conclusion that ‘GM does not have the DI issues that BMW or Volkswagen have’ — are there articles or videos I can watch to educate myself? I am curious about walnut blasting too and when it’s appropriate on a C7 Z06…
Google is your friend. Build a Google Search to find information on how many GM DI engines have had carbon deposit issues. GM has been delivering DI engines since 2007 and has 100s of thousands or more on the road. The big complaint about the GM V6 DI engines wasn't about carbon deposits it was about timing chains breaking and destroying the engines. As it turns out non of the domestic OEMs seem to have a history of carbon issues with their DI engines.
Google is your friend. Build a Google Search to find information on how many GM DI engines have had carbon deposit issues. GM has been delivering DI engines since 2007 and has 100s of thousands or more on the road. The big complaint about the GM V6 DI engines wasn't about carbon deposits it was about timing chains breaking and destroying the engines. As it turns out non of the domestic OEMs seem to have a history of carbon issues with their DI engines.
Bill
Timing chain wear may be exacerbated by DI, as there is a buildup of soot in the oil and the soot is abrasive.
In the Audi world the 2.0T need timing chain replacement about every 80k. The theory is that soot from DI is getting into the pins and wearing the chain (among other issues). The solution seems to be shorter OCI and using oil specifically designed for Di engines.
Google is your friend. Build a Google Search to find information on how many GM DI engines have had carbon deposit issues. GM has been delivering DI engines since 2007 and has 100s of thousands or more on the road. The big complaint about the GM V6 DI engines wasn't about carbon deposits it was about timing chains breaking and destroying the engines. As it turns out non of the domestic OEMs seem to have a history of carbon issues with their DI engines.
Bill
More like millions in the full size trucks and SUVs alone. Corvette production is a rounding error by comparison.
