Originally Posted by vtmbz

you have hydraulic lifters so no valve adjustment is possible. Either the lifters work or they do not. Clean oil is important. My valve train improved over time.

I dont know if the relay is vital or not-- with mine, the engine stays at the right temp winter and summer although I never get caught up in traffic, since there isnt any here. I've heard that with this engine, the fan clutch, which is electrical, doesnt deploy unless the ac is engaged. I dont know if this is true or not, my fan clutch never seems to work, but as noted, I've never needed it.