myers_jas

I have a 1994 toyota pickup with a V6, 3VZE engine. I recently washed the engine and now the hose leading into the PAIR valve makes a bubbling/gurgling noise after engine start up and especially during deceleration. I have strict emissions standards where I live so removing the valve isn't really an option for me.

When I remove the hose connected to the valve the noise stops. My mechanic thinks that the vacuum isn't sealed and some air is being sucked in from outside the system. Does anybody know an easy fix for this? The noise is very distracting and now that I am considering selling the truck I don't want something like this to drive the price down.

Thanks!!!

Jason

By the way, there are 71,000 miles on the engine.

Gamefreakgc

There's two main hoses on the PAIR system, plus lines from the VSV http://personal.utulsa.edu/~nathan-b...78pulsedse.pdf. If it's the one leading from the front Air Chamber over to those boxes next to your air cleaner/VAFM, then that's an easy fix. If it's the one from the back of the Air Chamber to the PAIR valve, then good luck! Mine had corroded and was so stuck on that I couldn't get the Air Chamber off. 1 hour later with an Xacto knife and a whole lot of pulling it finally gave way. Get rid of those silly tension clamps and put on a hose clamp with a screw.

Check you VSV before you decide to do that, it may be broken and not closing the PAIR valve. It should only be open when the engine is cold or decelerating. Since you can hear yours (it's a hose problem somewhere) make sure you only hear it during those conditions.

scope103

You probably have one or more loose screws on the PAIR; that will produce a classic buzzing sound. If you have small hands and a stubby screwdriver, you may be able to fix it without much disassembly. Consider replacing them with allen-head screws; they don't cost much more and are easier to get to with an allen wrench. 5mmx10mm should do it.

The large hose connecting the PAIR to the metal tubes under the plenum is, as gamefreakgc points out, hard to disconnect because it so hard to get to. I suggest using a heatgun or even a hair dryer to GENTLY warm the rubber. It will make it a tiny bit softer, and make a lot of difference for removing it.

myers_jas

On the passenger side under the hood there is a grouping of 8 or 9 hoses. The hose marked with the number "4" is the one that seems to be making the noise. I am TERRIBLE with cars but I THINK that this is the hose that connects the VSV (whatever that it) to the PAIR valve but it COULD be a hose that connects to the EGR valve (whatever that is, too).

I've been pouring through the engine diagrams/schematics but it may as well be written in greek.

myers_jas

Sorry for the quick double post but I had a little more info: the reason I think it's this number 4 hose is because when I unplug it from the valve the noise stops, then when I re-connect it the noise starts up again.

I've read about the PAIR valve screw issues but I don't think that's it because the noise sounds like gas escaping and not like a rattling sound which i would think a lose screw would sound like. Either way, I will check the screws just to be sure.

Gamefreakgc

I can't speak to the numbering, most of my hoses have been replaced and don't have that anymore. However, chances are that's one of the hoses that operates the VSV. That's those small contraptions bolted to the frame right above you passenger side wheel well, I think there's three of them. (follow the hose). By disconnecting it, it disables your PAIR reed valve so that it doesn't open, I believe.

Like I said before, the PAIR valve should only make noise on cold starts for a few minutes, or when decelerating. Since you can hear it, drive it around to make sure it only runs during that time. If not, you're going to need to replace the VSV, in addition to replacing the hose that has the leak in it causing all the noise in the first place.

scope103

For what it's worth, the stock #4 vacuum line goes from the PAIR VSV to the PAIR valve. If your hoses have been moved (like Gamefreakgc), then we can't say.

The PAIR VSV is the furthest aft of the four. The other side of the VSV goes to the orange side of a black/orange check valve, then to the "gas filter" (three nipples on the side of the plenum) via hose #1.

Why don't you put your hand on the PAIR valve. Do you feel it when it makes noise? Can you feel all four screws; is one of them loose? Could you have fluid of some sort in the valve?