Why would a noisy injector get less noisy as the engine warms up? There is injector noise but there is also this other thing in this thread that we don’t believe is injector noise. Waiting to hear back from Toyota on the actual issue.
Lemon already?
- Thread starter Robbie
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They operate at a much higher pressure when the engine is cold.
There is a thread on the “other” forum that suggests something like 50psi when warm vs. 2500psi when cold.
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engine knock noise
I also don't think this sounds like an injector. But... I have been wrong before. To me is sounds like an exhaust leak but I was told it was a cylinder 1 issue. Still waiting on official word back from Toyota Product Engineering.
Would laugh my butt off if it's an injector.
I have this noise and it does go away when warmed up. Seems part of the design, whatever it is since it is NOT random. Only specific engine loads, and only when the temp is coming up.
That said, I haven't given it much thought. My Mercedes had/has a similar lifter noise when cold. MBworld was full of posts deriding MB's downhill quality lol . 16 years and 255k miles later, that motor and transmission continue to set the bar on reliability.
Just because a user says it's a knock, doesn't mean it is one.
That said, I haven't given it much thought. My Mercedes had/has a similar lifter noise when cold. MBworld was full of posts deriding MB's downhill quality lol . 16 years and 255k miles later, that motor and transmission continue to set the bar on reliability.
Just because a user says it's a knock, doesn't mean it is one.
I think most of my comment around knock have been met with “question mark?” After it. Like “engine knock?” I’ve called out many times I thought it was an exhaust leak. The mechanics tore the engine down because of the sound.
Someone else in here posted a video of how loud the engine was from outside and I believe that one was presumed to be injectors. I do know on other Toyotas the injectors can be ridiculously loud and it varies in intensity whether it’s in a direct injection or port injection cycle.
Not saying that’s what you’re experiencing just noting that loud seems to be the norm.
The fact they ripped into the engine would seem to indicate at least someone thought there was another culprit.
Not saying that’s what you’re experiencing just noting that loud seems to be the norm.
The fact they ripped into the engine would seem to indicate at least someone thought there was another culprit.
It is somewhat similar to the direct injector noise of the Camry engine on this video. Especially after 30 second mark.
Or this video
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Perhaps because the D4S system will transition to port injection at idle once warmed up to prevent low engine load carbon build up, and take advantage of certain engine load conditions where port injection is more efficient than direct injection.
Probably the closest thing I've read on this thread.......
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Just my guess.
Start with the simplest explanation first.
Why is it noisy on a cold start? Because DI injectors are freakin’ noisy and this engine doesn’t have a cover on it.
Plus the engine will run pig rich to warm up the catalytic converter. The colder it is outside the more racket it’s going to make doing it. Hell it probably runs both DI and port on startup for all we know and sends vacuum to open the wastegate and get heat to the catalytic converter. If it has secondary air injection it will run that too when it’s cold to help push air to the catalytic converter, which makes noise for a few seconds.
Once it’s warm all that will change because the emissions system is “happy”.
