i havethe B5 S4. Would a leaking head gasket cause the low oil pressure light to come on and off when im driving.

 

In short... no. Low oil pressure is either due to low oil, or a fualty oil pump. You should check or replace the sending unit first. To make sure it's not just the bad sensor. If you really have low oil pressure, your engine will knock, then you'll continue to damage it by driving it. The oil pump is like the heart of your engine, when it fails your blood (oil) stops cirulating and you can imagine how bad that would be if you engine wasn't getting oiled internally. You can completely ruin an engine by running it with a bad oil pump. The screen to the pump could be clogged with sludge preventing the oil to get to the pump. Won't know without dropping the pan and having a look inside the bottom of the engine.

My recommendation: replace sender and have a shop do a test to verify actual oil pressure with a mechanical gauge. This should be on your #1 priority list right now. It can get very expensive to rebuild or replace a 2.7t engine.

The head gasket seperates the water passages in the head, from the combustion chamber. When they "blow" the antifreeze pours into the cylinder, causing a ton of white smoke and then the engine over heats from loss of coolant. You can usually smell the sweet smell of antifreeze in the exhaust. Also having all that antifreeze leaking into the combustion chamber can wash down the cylinder walls causing excessive wear to the cylinder walls, piston rings, and if it seeps past the rings you can wash the oil off your bearings and spin a rod bearing damaging a journal on your crankshaft so the bearing(s) would need to be replaced and the crankshaft would have to be honed, re-cut, or replaced.

This is not specific to an S4, this is general engine theory.