There is oil in the water and it keeps overhaeting; have flushed the hoses and it still overheats

Check your oil dats da only other solution to this problem your car might be burning oil and cause it to run hot

If you got a blown head gasket, water is getting mixed with your oil, pretty much ruining it, and your oil's viscosity will be affected, causing oil pressure to drop and your light turns on.

How do you know your car is overheating if it's not showing in your gauge?

When replacing blown gaskets there are a few things that is best to do, like sandblasting the heads, clean, scrape block and use proper torque an sequence, only removing old gasket and placing new ones won't fix the issue, those gaskets go through extreme conditions, expansion, temp changes, etc, they need to be put mindfully. I mention this because it seems you changed a lot and ended up with the original issue...

If your gasket is blown you need to fix that asap, then identify where is your coolant leak/blockage that causes alleged overheating, doing a coolant flush might help. Good luck.

Ask a skilled mechanic to have a look as the causes can be numerous from a head gasket to a water pump impeller

is your water pump circulating the water nissans used to have a problem with impellers on pump
leave rad cap off and run enginge should see water circulating when stat opens

blow head gasket or cracked head

it could be the thermostat has gone bad-does top hose get hot if no then likely bad thermostat, water pump is bad if pulley is wobbly it is bad, radiator is clogged with corrosion, look in rad when cold and if it is dirty or milky it needs flush and refill with new antifreeze

check the casting on your replacement water pump..4.0l engines require a reverse rotating water pump..may be causing your problem.

sounds like oil in the water blown head gasket check oil to see if iy is same color as water

remove coolant.remove thermostat remove bottom radiator hose to water pump.put a empty container under the radiator.take a water hose put it where thermostat goes flush out the rust in block.watch the water as it come out the water pump .if stream water is small keep flushing until you get a study sream of clear water. also flush out radiator. lower water pressure dont flush radiator it with high water pressure you could burst it. make clean the over flow jug .make sure it not stopped up.put in a new thermostat and radiator pressure cap. fill radiator with half antifreeze and half water.bleed the coolant system.

its under the throttle body near the coil pack