2003 Whistling Noise (revisited)

In my thread from before, I explained how about a week or two after cleaning the throttle body, I started experiencing a whistling noise coming through.

Recently, I installed a K&N intake. Truck sounds beautiful and runs beautifully. However, the whistling noise is a lot more prevalent. Mechanic said there were no vacuum leaks or anything of that nature. The noise—expectedly—got louder after installing the intake, leading me to believe it’s intake-related. Howe’s were replaced and are nice and snug, as well.

It’s loud enough to be heard on video, as well.

Not sure how videos work on here, but you can hear it through the video. I believe it starts from like 1/4 throttle, peaks at 1/2, back down at 3/4, then no whistle, then it shifts after a bit more throttle after it quiets down.

Seems to not affect performance; I just don’t want it to turn into a larger problem.

Videos:

https://imgur.com/a/qPlztBT

https://imgur.com/a/PssuIR7

Any ideas would be appreciated

 

Hard to tell from the video. Are you sure it's engine related and not wind noise entering the cab? My initial thought was something disconnected under the hood but you say the mechanic couldn't find any vacuum leaks. I think the intake is your most likely cause. Can you switch it back to the OEM intake and see if the noise persists? Then you could at least rule that out.

 

I can't quite hear the whistle from the video. But here is a thread to check out: https://www.tundras.com/threads/diy...-adding-high-flow-air-filter.2619/#post-38681

There is a well known instance of whistling that occurs when switching to any sort of high flow intake. There is a gasket with a screen at the throttle body that causes some whistling. It is possible to switch the gasket to a version without the screen to remove the whistling.

 

Both me and my buddy checked the intake and all the hoses after install both with engine off, on, and after driving for awhile. I also check it at least once a day so far.

Also, the whistling noise was there before the K&N, it just wasn’t as loud.

I did see a couple forums about the gasket before, but mine doesn’t have one.

I thought it might be cabin-related, but it’s dependent on RPM’s and not speed, which leads me to engine-related.

Here soon I’ll check every hose I can find to make sure it’s nice and tight. I was probably gonna replace them when cleaning the engine bay, as well.

Thank y’all for the replies

 

I may have found a potential culprit, but at the same time I have no experience whatsoever and it may be perfectly fine or not even a vacuum line

https://imgur.com/a/klSDPUR

 

Put your old intake back on and see what happens.

 

So there was a whistling noise before you changed to the aftermarket intake?

When I first bought my truck, I noticed a similar whistle but only after 3000rpm. It wasn't till I got it in the shop on the weekend to do all the services I noticed it did not have an air filter in it...

Sometimes aftermarket CAI make noise. I know throttle body spacers will do the same thing. In theory, it should do it in neutral with someone throttling it so maybe have a friend do that while you poke your head under the hood. My guess is something isn't sealed all the way and it's pulling air from somewhere it shouldn't be.

 

Sorry I just have to,,,,if I have a whistle.. I probably have a boogie in my nose......