engine sound / function question

[SSPey]

seems to me that engine noise in the 5th Gen doesn't clearly reflect RPMs, and I am curious how the engine works to make that noise. It isn't something I had experienced in my 4-cyl Tacoma or 8-cyl Tundra

For example, when the engine is started in Park, there is a lot of noise as if a fan is really working hard. The noise goes away once shifted into gear, in idle. Then when the accelerator is pressed to start moving, it again makes a lot of noise that seems much greater than the RPM.

Is this the fan, or what, and what's the design philosophy? I remember the old Chevy Blazers made all this "noise without power" but never understood what it was about

 

[03_4x4Runner]

From the few 5th gens I test drove it seems like toyota really cut back on sound deadening. All the 5th gens I tested the engine sounded rough/noisy even the limited.

 

[harper7]

seems to me that engine noise in the 5th Gen doesn't clearly reflect RPMs, and I am curious how the engine works to make that noise. It isn't something I had experienced in my 4-cyl Tacoma or 8-cyl Tundra

For example, when the engine is started in Park, there is a lot of noise as if a fan is really working hard. The noise goes away once shifted into gear, in idle. Then when the accelerator is pressed to start moving, it again makes a lot of noise that seems much greater than the RPM.

Is this the fan, or what, and what's the design philosophy? I remember the old Chevy Blazers made all this "noise without power" but never understood what it was about

Could be the fan clutch engaging and disengaging the fan as needed. Mine doesn't seem that loud but my hood does have sound deadening insulation on it.

Here is another thread on the SR5 engine noise..... http://www.toyota-4runner.org/5th-gen-t4rs/70561-2010-sr5-engine-sound.html

And here is a good read on the improvements made on the engine starting in 2010 for the FJ and the 4Runner. They use the same engine. 2010 1GR-FE Engine Improvements

 

[SSPey]

must be the fan noise that I am noticing ... so the question about "function" becomes: why have a fan designed like this? I like a good rumble out of an engine, but the "whoosh" of a fan, not so much. What's the performance advantage? Does this engine run hotter, or require more cooling, than the 4-cyl and 8-cyl engines in previous Toyotas?

 

[Ryan_S]

The clutch driven fan is an older design I believe. Most cars now have an electric fan.

Personally I like the clutch fan. It seems more reliable (I have absolutely no data to back that up). Although I'm sure there is some fuel economy gains to be has with an electric, and of course the noise issue.

 

[DigableKid]

The engine does sound a lot louder than my V8 07'. When I'm driving, it sounds like I have a heavy right foot. Whonnnnggg is the sound.

It's all good though. I just drown it out with my 15 speaker sound system.