Fix for tapping at idle.

[mikesfj]

That annoying tapping sound you hear at idle is not your lifters, injectors or your headers. There is an emission control component called the PWM-vacuum switching valve screwed to the intake manifold on the drivers side. You can access it by removing the plastic shield over the intake manifold. It is held in place by a single screw. This thing activates when the vehicle is at idle and at temperature.
To minimize the tapping sound coming from it, you nee to isolate this component from the manifold. The manifold is resonating the sound from the valve making it loud.
Here's what I did to minimize the noise:

You will need 2 rubber o-rings ( I used R03 nitrile o-rings) and a 10 mm Nutdriver or wrench.
After removing engine cover,
remove bolt that holds the valve to the manifold (no need to disconnect any lines or harness)
Place an O-ring on the bolt and push it to the head of the bolt.
Slip the bolt through the valve and slide the other o-ring over the bolt.
re attach valve tightening enough to compress the o-ring and snug the bolt. The o-rings should be enough to keep the bolt from vibrating out.
Replace cover and enjoy the silence!
***This may not eliminate this noise, but it sure quieted mine down.

So, don't worry about trying different weight oil (use the recommended only) or any other drastic measures. From what I have read, most if not all toyotas in the last 5 years have this tick. Maybe the factory should do something about it. I think that Toyota should find a quieter valve or make an isolated mounting kit.

[Cruzer]

Wow, great find, I'll open up the old boy tomorrow and check it out!
~C

[Fixxer]

Mike,

Glad you found the problem.
IMO, as long as I know that the tapping isn't detrimental, I'd leave it alone.

[Chatsworth 818 FJ]

wow, please do pics someone, and where is this on the TRD CAI? I havent payed attention to see if it even still taps with the CAI.

[DominicG]

your my new hero.

[frogeye]

Man, I just don't hear it. All my previous Toyotas made the same sounds. The engine sounds like a sewing machine.

[hero]

I was just going to ask what the hell that tapping noise is...

I noticed it yesterday every time I had to pull over to knock the ice buildup off the wipers... 2006 Storm #2 Pics

[mikesfj]

frogeye previously said:

Man, I just don't hear it. All my previous Toyotas made the same sounds. The engine sounds like a sewing machine.

The 4.0 motor should idle very smooth and quietly. Mechanically they are tight. According to my stethoscope and ear, the only source of noise on this motor is an annoying little valve that makes it sound like a sewing machine. I removed mine completely (left it hanging by the hose)and could barely hear it clicking, but when screwed solid to the hollow plastic intake manifold, the sound is amplified. It needs a rubber isolator to deaden the sound. You can put your finger on the valve and feel it.
Maybe some of these valves are defective?

Any Toyota techs out there know about this???

It may be a non-issue to toyota.

My previous posted solution may be a "bandaid" to the real problem or a viable solution.

[EpicMale]

mikesfj previously said:

The 4.0 motor should idle very smooth and quietly. Mechanically they are tight. According to my stethoscope and ear, the only source of noise on this motor is an annoying little valve that makes it sound like a sewing machine. I removed mine completely (left it hanging by the hose)and could barely hear it clicking, but when screwed solid to the hollow plastic intake manifold, the sound is amplified. It needs a rubber isolator to deaden the sound. You can put your finger on the valve and feel it.
Maybe some of these valves are defective?

Any Toyota techs out there know about this???

It may be a non-issue to toyota.

My previous posted solution may be a "bandaid" to the real problem or a viable solution.

Strange that this valve makes noise on some FJs, but not others. I wonder if there was a change made during this build.

Thanks, if my FJ starts ticking, I'll know how to fix it!

[Noisycow]

I don't have this tapping at idle, even when the FJ is cold. Got mine in late Sept. Maybe Toyota made adjustments for it?