Camshaft Failure

How did the camshaft fail exactly?

The camshaft was not removed from the car but the failure is inside or just beside the first bearing closest to the timing belt/pulley.

It's not their fault. The engine oil passage feeding oil to the cam bearings plugged up and the cam seized in the engine.

Right, makes you wonder what the oil change interval was.

I'm sure it missed a few. One thing people don't consider are the hours an engine runs. In stop and go - traffic jam type use, 3000 miles is WAY too long to go between oil changes.

I always thought cars should have an "hours" meter. Some of the european cars use a variety of ECM data to indicate when to turn on the "change oil" indicator. That's probably more reliable than a static # of miles.

The car had the oil changed every 5,000 miles or less when I used both Mobile 1 Synthetic or later regular Quaker State oil. If my memory is right, the manual says to change every 7 or 8000 miles. Is lack of oil the only reason the camshaft would fail? Normally lack of oil would cause the bearings to fail and stress would cause a shaft to fail. This is in the aerospace world - perhaps different in the auto world. Camshaft failures on the Maxima engine are rare so if it was oil related I would expect to hear about more of them. I'm favoring a rebuilt factor engine rather than repair the existing one.

When you say the camshaft failed... are you saying it broke? as in two pieces? if so... hard to see how an oil failure could cause that... seems much more likely to be a residual fracture in the cam that was aggravated by the mechanic as he replaced the belt, changing loads and stresses in the process.

BuddyWh