Alternative Theory

[kkrehbiel]

Is it possible to damage, or render inoperable, an Alternator by not changing a worn fan (serpentine) belt?

Also, what might cause Gas to be in the oil? This is on a Chevy V6 w/ Fuel Injection.

Thanks!

-K

[ivymike1031]

If the belt no longer drives the alternator, then the alternator will not perform its job. If the belt is too tight, the loads on the alternator's pulley bearings will be too high, and the bearings may fail prematurely.

Gas can get into the oil through several routes. If you have a mechanical fuel pump that bolts to the side of the engine and is driven by the cam, then it is possible that a failure of that pump could cause gasoline to leak into the oil.

Other routes include:
* Past the piston rings: if the piston rings are badly worn, then unburned charge and some combustion products will blow past the rings ("blow-by") and end up in the oil. In all engines, a certain amount of blow-by occurs, regardless of how worn the rings are, and is considered normal.
* A bad head gasket can allow passage of combustion products into the crankcase, as above
* In nearly all engines, a thin coating of oil will remain on the cylinder wall above the piston. Unburned fuel and/or combustion products can diffuse into this layer of oil. The combustion products typically re-emerge in the combustion chamber after combustion is complete, resulting in higher tailpipe HC emissions, but it is conceivable that some amount of fuel will end up in the crankcase this way.

I've probably forgotten something, so expect to hear from others as well.