Whistle while driving

[BrandonD29]

Between 1800-2500rpm at 1/3 or less throttle, i get a nasty whistle noise. I have an aftermarket cai.

I recently took off the throttle body spacer i had, tossed it in the garbage, bought shorter bolts and snugged up the throttle body (torqued to spec) However it still sounds like i have the exact same whistle even though i took the spacer out.

Today i noticed a vacuum line conmecting to the intake had a crack, which i replaced, but still the same whistle.

In neutral/park there is no problem. Only drive and reverse.


I thought maybe it could be a bad bearing on a pulley run by the belt? But im all ears for suggestions. This has caused some severe road rage.

 

[Redtruck-VA]

Check the other vacum line...

 

[BrandonD29]

What!?! There are 2??? I think i may be ********

 

[Redtruck-VA]

There"s two vacuum lines on the drivers side of the intakes manifold, one goes to the vacuum booster the smaller hose goes to the purge valve. Both are easy to knock off or split.

 

[BrandonD29]

Old pic. But i swapped the ome with the zip tie around it

 

[Redtruck-VA]

Thats a crankcase vent line, not vacuum. Many folks plug the end on the intake tube and put a small filter on the other end.

 

[BrandonD29]

There"s two vacuum lines on the drivers side of the intakes manifold, one goes to the vacuum booster the smaller hose goes to the purge valve. Both are easy to knock off or split.

The one in the far far back ledt of the pic?

 

[Redtruck-VA]

The one in the far far back ledt of the pic?

Yes, those are vacuum hoses

 

[BrandonD29]

Well dont i feel dumb haha.

Ok. I will check out both hoses for leaks.

And i guess find a small filter instead of a vent line

 

[BrandonD29]

All hoses appear solid. No sound change when i sprayed soapy water all around

 

[Redtruck-VA]

The smaller of the two (purge valve) has some hard plastic sections and become brittle. Might check it by pulling it loose and capping the source so it can't whistle.

 

[BrandonD29]

Felt the line up amd down amd didnt feel anything loose. Ill have to disconnect it tomorrow when i have more light and see if i still have the whistle. Thanks for the help.

Got any other ideas just incase?

 

[Jason G Slabaugh]

I usually whistle while driving cause I dont know the word's to the songs playing in truck.

 

[Elevated 2013]

Does the noise change with engine speed or just vehicle speed? Could you have a leak in the throttle body gasket? Did you replace the gasket when you took the spacer out or put it in? Is your idle rough or smooth? If it's smooth it's probably not a vacuum leak as that usually causes the tachometer needle to fluctuate where a normal idle you will barely see the needle move.

 

[BrandonD29]

Does the noise change with engine speed or just vehicle speed? Could you have a leak in the throttle body gasket? Did you replace the gasket when you took the spacer out or put it in? Is your idle rough or smooth? If it's smooth it's probably not a vacuum leak as that usually causes the tachometer needle to fluctuate where a normal idle you will barely see the needle move.

Smooth idle. I did replace the gasket. I put some air tight sealant. Then the gasket. Then sealant. Then my air intake.

Engine speed seems to be what is causing the issue. However it only whistles in drive.

 

[Elevated 2013]

Only because I want to make 100% sure that I understand what you just said and what you said to begin with, it only happens in Drive or Reverse between 1300-2500 RPM? Do you have to be moving or is this just revving the engine a little bit? If you have to be moving then it's time to look somewhere other than the engine. With the idle being smooth and not high, I doubt it's a vacuum leak unless it's in a super small hose somewhere that doesn't need much vacuum if it is a vacuum leak.

 

[BrandonD29]

Yep. Drive or reverse 1800-2500 when throttle is pushed in about 1/3. And more and the noise goes away

 

[OldMaster]

Hi,
I only read the post very quick, so i might have missed some info. but can it be a faulty wheel bearing?

 

[BrandonD29]

Hi,
I only read the post very quick, so i might have missed some info. but can it be a faulty wheel bearing?

I dont think so, becusse it only happens between certian rpm ranges. It starts and stops depending on how much i press the gas pedal. Not the speed im going

 

[Stevieh]

Anyone ever get anywhere with this? Have the exact same issue I’ve been trying to track down for months now.