yackowski

I started my car the other day in the parking garage at work (roughly 64 degrees according to the dash) and I got several codes immediately. I also have this annoying humming/whining noise that goes up and down with the RPM. It doesn't really sound like my 4 month old alternator bearing went out (too low and mellow-ish if that makes sense) or my serpentine is slipping really? Could it be my SAIS valve hung open or something along those lines? I kind of felt like it was too warm for that system to operate anyway?

Anyway, I dropped it off at the NTB beside our office (the replaced the alternator for me when I didn't have time) and they couldn't find anything wrong with the belt/pulleys/alternator and said it sounded like it was coming from the intake.

Confirmed
P0456

Pending
P0441
P0455
P0456

Any ideas? Anyone have a similar situation?

Thanks,
Cole

Listers

Have you searched the Secondary Air Injection Pump? Somewhat common and costly problem with the emissions system on the GX470.

sheikhmax

Secondary Air Injection pump noise goes away.
Check the following?
Since the Alt was replace see if that whining is due to power steering pump that is right up top of Alt.
Or
Try the cheapest solution first and get the gas tank cap from Toyota Dealer and replace it. P0456 is vapors escaping from EVAP emission system.

yackowski

*I should have mentioned that I had already ordered a new gas cap seal and that appears to have solved the code issues.

I think this is the same (aggressive vacuum cleaner) noise I used to hear when I would start my car in the morning, but now it doesn't make the strange noise and abruptly quit after a brief period. It just continues to make the noise all the time and sounds like I have a baby supercharger under the hood.

I have read a billion threads about the SAIS and it doesn't appear I am getting any of codes related to that system. I also thought the noise wouldn't be be continuous, but was a little thrown when I listened to a YouTube video of the intake fan with broken blades and it sounded very similar to my sound if not the same.

I also thought about the power steering pump, but the noise doesn't really wine like the old Ford pumps I've dealt with all my life anyway. The minimal RPM drop when you turn appears to be the only noticeable change to the sound in relation to turning (in place or moving). The fact that it does change ever so slightly with RPM does point me toward serpentine related issues.. I find it odd that the mechanic at NTB wouldn't diagnose that tho? They are usually pretty good at suggesting you purchase parts lol, needed or not.

It's going to be a couple weeks before I have time to head back home and tear the issue any further. I'm busy with work and I guess I'll just drive it and hope for the best in the meantime. I'm just hoping someone has had similar issues ans can save me some time with the diagnosis.

Anyway, thanks for any help, guys!

Cole

chiph9

What part of the engine compartment is it coming from?

Chip H.

yackowski

Chip,

I really haven't had the time to take it apart and spend much time messing with it lately. I am going to take the cowls and skids off one evening this week and see if I can locate the noise. It just sounds like the intake/front center of the engine is making the noise with only the hood up.

yackowski

I finally checked out my whining issue today. It turns out it was my alternator after all. I guess I had a diode go out. First time for everything I suppose. I have definitely not heard this particular sound before except when the OEM alternator completely died. I unpinned the side cover in the passenger side wheel well and disconnected the wire connected to the alternator and the sound went away immediately. I actually shot a video of me touching and removing the wire and showed it to the mechanic at NTB this afternoon. They replaced the alternator free of charge.

This sound in this YouTube video is spot on for anyone that is experiencing similar issues.


Cole