Hi Kim Monroe,
If the timing belt tension is not tight enough, warm starting might cause some abnormal noise. If the noise disappears after the engine has warmed up, it should not be a rod problem.
A rod problem would have the knocking noise during sudden acceleration or revving up the engine.
If oil treatment had been used previously, it could cause partial clogging which can cause the oil to travel slower during starting, thus the noise.
If the valve could not be adjusted, the rocker arm could be taken out and replaced if necessary. The adjusting screw could have been stuck due to sludge and twisting it a few times should get it going.
Saturday, July 5th, 2008 AT 8:48 AM