Hey guys,

I am at 900 miles and just did my first sporty driving yesterday. I did not push it too hard (7k or so max, though once, just once, I did go to the beep). All good, all fun. BTW, after some highway and sporty driving, I got 20 mpg (5 gals for 100 miles of fun).

I have some comments about noises the engine makes:

1. When it is cold (meaning in garage, say 60-degrees) and just started up I hear this very mild vibration underneath the car. It sounds like a cover of some part of the exhaust system (catalytic convertor shield?) vibrating a bit. I say this because I have heard this sound before, at least it seemed similar, on another car that had that problem (a 300ZX). But when engine warmed up after some driving, it was all gone. What gives?

2. This is perpetual question of mine: if you have the vents on feet and windshield, and the temperature on mid to cold, does the AC turn on behind your back? I seem to hear this clicking and changing engine sound periodically at idle. I should pop the hood and look when this is happening, but in general I wonder does the AC turn on (even if the button is off) when windshield defrost is on? BTW, my 4runner seems to exhibit similar weirdnesses.

3. The engine really sounds nice at higher rpms and is truely smooth. I can compare to my BMW E30 325i which is in great shape and sounds nice too but near its max RPM you can tell it is stressed.

4. The sound when you accelerate in 2nd or 3rd to a high RPM and then remove your foot from the throttle and let the car coast (but in gear) is great! Its like a turbine winding down or something. Awesome!

 

1. dont know i dont have this noise. is your car a 2005?
2. anytime the floor is selected defrost is automaticlly selected. any time defrost is on the AC is on. whether it is indicated or not.

 

#1 might be the air pump that runs when the car is first started cold... brings the cat up to temperature quicker...

 

My car is a 2004, 4/04 build date, with GT and AP packages.

Thanks for the AC bit and for the air for the cat converter bit. Where can I read more about the cat air warming thing?

 

I don't know where it's documented, but it's an emmissions thing- by pumping in fresh air when the engine is cold the cat can reach operating temp faster and burn cleaner. It's an electric pump located on the left side under your shock tower brace, circled in this pic below... maybe next time you hear it, open your hood and put your ear to that thing to see if that's the culprit.

 

"2. anytime the floor is selected defrost is automaticlly selected. any time defrost is on the AC is on. whether it is indicated or not."[/I]

The AC won't operate below a certain temperature though. Certainly not at minus 32C, which is what it is here today.

 

G8rboy,

I see you engine cover is off --- is it always? Does it cause any problems?

 

The cover won't fit of the strut brace he has. It doesn't on a lot of aftermarket braces. No known issues with it off....

 

[QUOTE=zoomallday]Hey guys,


I have some comments about noises the engine makes:

1. When it is cold (meaning in garage, say 60-degrees) and just started up I hear this very mild vibration underneath the car. It sounds like a cover of some part of the exhaust system (catalytic convertor shield?) vibrating a bit. I say this because I have heard this sound before, at least it seemed similar, on another car that had that problem (a 300ZX). But when engine warmed up after some driving, it was all gone. What gives?\

The noise you are hearing when you start up is an air bypass valve, I have the same noise on mine, I talked to the Service Dept and thats what he told me it was.

Have fun driving- I just hit 15K miles, alls good.