I have a '94 toyota pickup 2wd with a 22re. There is a strange noise coming from seemingly the back middle of the engine. It sounds like a relay going crazy (a very fast, hi pitched, sporadic sound). I recently have replaced the head (including the valves, valve springs and cam), adjusted the valves twice warm, replaced the timing set (including guides), replaced the water pump, oil pump, timing cover and Idle Air Control Valve. The timing is set at 5 degrees btdc. Aside from a minor idling issue the engine runs great but the noise is driving me crazy! Any help would be greatly appreciated! Thanks!

 

It might be the pulsed air thing that goes the the exhaust manifold. Just a shot in the dark but I can't think of anything else that would cause that. Maybe a pulley or the throw out bearing on the clutch? sorry I couldn't be more help

 

Is it the back or the middle? Is it more noticible on the intake or exhaust side?
All 4 fuel injectors pulse once per engine revolution and are more 'click' than 'tap' like a loose valve would, and a valve would only tap once every other revolution anyhow.

Yeah, could be the PAIR valve but not likely if you have the resonator chamber hooked up to it.

 

if it seems to be an internal noise you can use a socket extension to go around and listen for which metallic part it is comming from, that is, if it is comming from a metal part. i'll agree with everyone else and guess PAIR valve.

 

it seems to be coming from the back middle. its not a steady sound, its very random. where is the PAIR valve and how do i check it? Thanks for the help!

 

it sould be some kind of valve system mounted near the exhaust manifold, i have the 3vze so idk where it is on the 22RE, check the Factory Service Manual. there should be a link to the FSM somewhere on this site.

 

Seems obvious, but you might check the metal plate that is bolted to the top of your valve cover. Should be three bolts holding it on. I misplaced one of my bolts once and without it the plate would rattle at odd rpms. I guess 2 bolts wasn't enough to keep it from rattling on occasion.

 

There is a bracket(s) that goes along the PAIR/heater pipes that attaches the pipes to the back of the head using the egr cooler plate bolt(s). The bracket(s) wrap(s) around both pipes. Maybe the bolt(s) is(are) loose after the head install and the pipes or the bracket(s) is(are) moving around hitting the pipe(s)?

or maybe those pipes got bent someone and are hitting/rubbing on the firewall.




The PAIR (reed) Valve is at the end of this pipe to the left and above the oil filter.

 

Thanks to all for the advice! It ended up being one of the Vacuum Switching Valves, or more specifically the filter (I guess that's what it is) on the end of it. Take the filter off the noise stops, barely touch it to the VSV and it starts making the noise again. I don't know how necessary the filters are. This one VSV out of the three is the only one with a filter.

 

you got a pic? not sure what your talking about, but I think I caught mine doing this today lol.

 

In the pic I'm pointing to the filter on the VSV that is making the noise.

 

ok I don't have one of those must be a efi thing.