bswindell

Hey guys, I've got an 87 P/U 2wd with 178k on the motor. Everything was well maintained. The engine runs great, plenty of power - no sputtering or missing but when it revs over 2000 rpm a loud tapping noise comes from what sounds like the top center of the engine. Initially I had so many people tell me to replace the timing chain that I did (avoid mizumoauto on ebay - poor quality). The problem was not solved. I then adjusted the valves (none were out of adjustment more than .001). Before I junk the thing I wanted to check with anyone to find out if there is anything it could be other than a rod? Getting a motor rebuilt will cost more than I paid for the truck.

People kept telling me how great these motors are and how they can go high mileage but if this one didn't very few will. The truck is a rust free CA vehicle formerly owned by a Army transportation officer. I've owned two 4 runners that gave me lots of problems so at this point i'm not really a Toyota fan.

abecedarian

if it's a rod bearing, the rod bearings are easy enough to replace without removing the engine from truck, provided the crank is in good condition. I suppose it could be the little end of a rod so that is a little more difficult, but still can be done without pulilng the engine out.
now you're saying tapping though, not knocking, so...
any evidence of an exhaust leak?
is the valve cover tightened down too much?
is the air-injection system working properly?

thook

The valve cover is a definite consideration. I've learned recently, though, a loud tapping can occur if the vehicle's running too lean. My fuel pump was on the skids and finally crapped out half way home on a 50 mile travel. So, might check fuel press.

Another thing........these are great motors. Very tough. But, that doesn't mean they won't have some issues particularly if they are older and used roughly. On the 22r/re's, it has been noted by some of experience that the factory tolerances on the valves are what could be considered rather loose. By the same folks, it's been suggested to actually tightened the valves somewhat tighter than factory. Plenty of threads covering this. I have done it with great success. Motor is fairly quiet for a 4cyl.