Do Direct-injection gas engines sound like diesel?

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Sometimes the fuel injectors can be noisy, depending on the design. Could also just be a noisy valvetrain.
 
Sounds normal for DI. My 2006 Accord is NA and the injectors are loud in it too, so I would say for DI this is normal.
 
My DI 135i is very quiet, while the injectors on my non-DI 318i tick and clack very loudly.
 
The noise is purposeful. It occurs after a cold engine start-up to warm up the catalyst to aid in reducing emissions.
 
Originally Posted By: JHZR2
My DI 135i is very quiet, while the injectors on my non-DI 318i tick and clack very loudly.


I had a new 328 for a day and the 4 banger turbo sounds exactly like a diesel when first started! DI needs an absorbent engine cover...
 
Direct inject gas motors operate very similarly to diesels. They must force the gas through over 1,000psi of pressure into the cylinder. This requires a lot of force, which can turn into that ticking/clicking sound if not properly damped. Some oems do a good job as hiding the noise, others don't care enough to do it. Really just personal preference.
 
I spent some time reading about gasoline direct injection. Apparently the main advantage is the ability to do lean burn (less gas injected). I thought lean burn engines had gone out of style, in order to meet California's strict NOx limits, but I guess not.
 
Originally Posted By: blackman777
I spent some time reading about gasoline direct injection. Apparently the main advantage is the ability to do lean burn (less gas injected). I thought lean burn engines had gone out of style, in order to meet California's strict NOx limits, but I guess not.


DI helps mitigate some of the issues that port injected lean burn has via additional control over the process and how / when the fuel is injected.
 
No. Most of the sound from a diesel comes from the fact that it "diesels", that is it depends on the compression to ignite the fuel/air, not a spark plug.
 
Lean-burn engines get outstanding fuel economy. Honda's lean engines in the insight & civic used to get 90mpg and 70mpg with careful driving (light foot on the throttle).

I bet these GDI engines could do some amazing things too, thanks to their lean burn operation. In fact one of them (Kia) got over 70mpg when driven by hypermiler Wayne Gerdes.
 
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