dirtroads_33

Hi all,
I just had a great marathon read in the Seafoam thread. Good stuff there. Something like three years long, my brain hurts.
I'm hoping someone with a 3VZ-E engine can relate to my issue. My 4Runner is a 92 with the auto transmission.
The other day I noticed a sound that was unusually loud under the hood. It's a dry, higher pitched kind of sound. I do not think it is normal because I had a buddy with the same engine pull up bumper to bumper with the hoods open and his doesn't make the sound.
When I opened the air cleaner box it got much louder, so I thought it might be from the air vane sensor being stuck or something. Upon closer inspection it was not stuck or dirty. So next, I rigged the vane open so the engine would continue to run and disconnected the big air intake tube from the vane sensor. This made the sound so loud that I thought the neighbors would stare.
It sounds dry. Like air being sucked thru an opening too small. But it also sounds like a dried out hi-speed bearing.
Any Ideas?
I've had the truck for three months, it runs well, has an ongoing code 25, 230,000km and gets 15.2mpg. All responses appreciated.

dirtroads_33

Is there a bearing in the top end of a 3VZE? Anybody?

2WDoffroadx

Dude, this kinda sounds like what happened after a seafoamed last week. I was revving too high..

Is your sound constant, or is it at random times? Mine is spurratic, and whenever i hear it, i think of something dry.
It's almost a hissing sound, so i though a vaccum line might be loose..But there isnt any loose lines.

Lysmachia

Hmmm very intersting. Keep us posted. I have a 93 auto but have not done the seafoam because well at 210K my engine was rebuilt (She is only at 225 now).

But I did have a horrific noise from my tranny yesterday. Turns out it was my newly rebuilt hub that locked my front driveline and ended up trashing 2 of my U joints (one in the cardain joint the other at the bottom of the driveline) But a small price to pay IMHO for a rig that should only be wheeled not driven on a regular basis like I am doing to her right now...

2WDoffroadx

225k? Rebuilt or not, thats a lot of miles. You should seafoam.

Lysmachia

I prolly should. Need to talk to my toyta tech budy who built her and sold her to me as I think he did at 200K

tombothetominator

Hmmm... i have a similiar sound coming from my airbox. I've been noticing it for about the past two years, and just never thought anything of it. Sounds like air being sucked through too small of a hole. I figured it was the AFM, but since it is running fine i didn't worry about it. Interested to see if you find what it is.

2WDoffroadx

Yeah, it hasnt affected performance at all for me..I'm wondering if I should even worry. If i take it to a shop, its my luck that the sound will stop when i get there.

snap-on

yes there is a HUGE bearing that the timming belt goes around right behind the upper water outlet (the water outlet goes THROUGH the bearing)

That bearing gets backed because it has hot coolant running through it ALL THE TIME = day you install it is the day it starts dying.

tombothetominator

I know mine isn't the timing belt bearing. Not only do i distinctly hear it from the air box, but that bearing just got replaced about a year ago. Tyler, DirtRoads - if you put your ear to the air box, is that where you hear the noise coming from?

dirtroads_33

Well Tombo, it's good to hear that your engine is still running with that sound after two years. I guess whatever the problem is it can't be too serious. But still that sound is wrong.
The "sound" definitely comes from the intake. I first noticed it from the air box and it got much louder when I un-clipped it at the filter. So I started removing more plumbing toward the throttle body and it got louder every time.
One tidbit of new info is that when I shut the engine off, this is the last sound I hear. It runs on for a few tenths of a second after everything else is quiet, but doesnt really follow anything visibly like the alternator.
Hey snap-on, nice photo. I hope that monster bearing is not the problem!
2WD, the sound is constant but at the same time sounds sputtery.
Molly, you look and awful lot like the girl from that movie "Who framed Roger Rabbit", maybe it's just my eyes (~8

TNRabbit

Reed Valve.

tombothetominator

That would make sense TNRabbit. The plastic tube that goes from my reed valve to the air box (goes from a metal air tube to a plastic one to the box next to the air filter right?) has been cracked for about the 2 years i have been hearing it. It's got electrical tape over it, which probably isn't keeping it sealed. I might try getting a new one of those hoses and see if that resolves the problem

Edit: found a link to the PAIR system diagram. I definately have at least one of these hoses cracked.
http://www.the-roo.com/4runner/Engin...s/pulsedse.pdf

dirtroads_33

Thanks TNRabbit. I made plans with my Isuzu-Trooper-crazy, father-in-law-to-be to work on our rigs this saturday. I'll check out that reed valve.

dirtroads_33

Got rained out but will get to the reed valve soon.

2WDoffroadx

My sound is coming from a busted timing guide.

dirtroads_33

Have you seen the busted timing guide? Maybe that's my issue. I've only owned this beast for four months approx. and don't know if the timing belt has ever been changed.

2WDoffroadx

I'm not on top about whether 92 4runners come with a t-chain or belt..
I don't think belts have guides..so if yours is running with a belt, its probably not a guide.

GSGALLANT

The 3.0 has a belt, not a chain, so you are correct... it isn't a guide problem.