Well, I tightened up the manifold and exhaust-to-manifold bolts, and still get the loud ticking when accelerating. If it were worn valve adjustment screws, wouldn't the noise be loud all the time? Is it as easy as taking the valve cover off to check the condition of those screws? I also noticed a very slight wetting around the edge of the valve cover...could be a bad valve cover gasket, but would that cause (or allow to be heard) the loud ticking?
>>>*One thing that might be happening is that exhaust leak is probably still there. Just snugging up the bolts may not completely seal the leak.
A leak around one exhaust port will make a noise similar to the one you describe, which is demonstrate under load yet quiet down at idle.
I would suggest changing the gasket, and while off check for the fairly common vertical crack on the inside of the manifold right in the center of the inside curve.
We see that quite a bit and it makes a sound like something banging around in there at engine speed while under load.
*The valve cover gasket will not cause any noise although an overly tightened valve cover can cause the rocker arm to contact the inside of the cover. We snug those holdown bolts just enough for the grommets to begin to bulge out, it won't fall off.
Another under load noise we find outselves chasing is a single cylinder ping. This is a bit like a soft tapping noise, the cause is usually carbon buildup from a cylinder using a small amount of oil. The stock compression ratio on the 22RE engine is pretty close to the edge for regular fuel, it doesn't take much to create some pinging.
If suspicious of that, run a tank of premium fuel through her, if the noise goes away then you know for sure.
One fix that often works if you do have some carbon buildup is to head out to the drag strip. Some nice full throttle runs will usually blow the carbon out..Besides, the Mitsubishi guys will have to give you a good head start....*LOL**....*EB
