98 Tacoma 3.4 engine tick

I just read through your thread. Your noise sounds very similar to an issue I had with a 2000 Tacoma 3.4.

I was concerned it was a rod bearing gone, but no evidence of metal shavings in the oil. The suggestion came up maybe it was a stuck valve lifter, as my latest oil change had been close to 1000 miles after my regular interval, and the truck was 225k+ on the clock. It was recommended I treat this by changing the oil, shorting half a quart of engine oil and making up the difference with half a quart of tranny oil. Something about the different viscosities would help free the stuck lifter. Ran that for 500 miles with the tranny oil in the engine and then did a normal oil change, and the noise was gone.

Did you ever figure out what your noise was?

 

The 3.4 has "shim over bucket" lifters. They're not hydraulic and therefore cannot "get stuck". The shims can be changed out for valve clearances, although this is very rare to ever require this. Just FYI

 

This is why I love the first gen forum.
Lot of knowledge and people getting dirty.