whining/bearing noise in the engine?????

[98frontier_islander]

i changed my ground from my battery to my block and test drove it.ran better than before.i was in second so decided to take it to 3500 rpm then shift quickly and stomp it again to 3500 rpm,then out it in neutral and roll to the stop light.

now i notice a whining noise around the intake manifold area and as i rev the motor it gets higher and as the whine slow down with the rpm i can hear a bearing spinning.

not to mention i smell a burning/melting smell coming from the back of the intake manifold too.

i checked my belts,pulleys,checked the obII's diagnostic codes,nothing.out of the 4 years i had my truck i never encountered this before,please help this is my daily driver.

1998 nissan frontier 4 cyl ka24de 2wd regular cab standard transmission

engines with the 240sx is almost the same besides a couple of parts.

[4cefed]

This may not help at all, but before you start tearing into things, check around for vacuum leaks. My SRT-4 was exhibiting the same kind of noise. I thought it was a high pitch bearing noise, but mine didn't change with rpm. I replaced a $75 belt tensioner, new serpentine belts, and had decided it was either timing belt tensioner or idler.

As it turns out, the intake manifold gasket was bad. It cost me $2.60 to replace. The SRTs have kind of an intake gasket problem, but it might be something to investigate before you go tearing into the engine.

[gumby74]

I can not think of any bearings on the intake manifold side or anything for that matter that would cover what you described.Possible you may have burned the clutch a little during your run? Maybe?