1995 jeep cherokee overheating...oil getting into coolant system.

If your Jeep is overheating and the coolant reservoir is bubbling, it could indicate that there is an issue with the cooling system. Here are a few possible causes:

1. The radiator cap is faulty: The radiator cap is responsible for maintaining the proper pressure in the cooling system. If it is not functioning properly, it could cause the coolant to boil and create bubbles in the reservoir.
2. The water pump is not working: The water pump circulates the coolant throughout the engine. If it is not working properly, the coolant may not be circulating as it should, which could cause the engine to overheat.
3. The thermostat is stuck: The thermostat is responsible for regulating the flow of coolant into the engine. If it is stuck in the closed position, it could restrict the flow of coolant and cause the engine to overheat.
4. There is a leak in the cooling system: If there is a leak in the cooling system, the coolant level in the reservoir may be low, which could cause the engine to overheat.

It is important to address any issues with the cooling system as soon as possible, as an overheating engine can cause serious damage. You may want to take your Jeep to a mechanic for further diagnosis and repair.

Replace the thermostat and bleed the air from the cooling system, then if it still overheats you may have a leaking cylinder head gasket. Any shop can detect the leakage with a gas analyzer by looking for the presence of combustion gases in the cooling system.

If the system is loosing coolant, it has be leaking from some place, either from a connection, gasket or out of the tail pipe. When you refilled the cooling system, did you start the engine and inspect the vehicle while it was running and at operating temp?

Generally no, the fan belt will not make a difference IF it is tight and turns the fan and water pump. A lot of things can affect the temperature of the coolant including the condition of the coolant. I have to switch my 1995 Jeep GC thermostat from a higher degree for the winter to a lower degree thermostat for the summer. I also found that using a syntinic (sp) oil helps during the summer.

You did not list what year or engine BUT: Overheating can be the product of either poor coolant flow through the radiator (either restricted air flow from leaves bugs etc. or internally blocked coolant passages.) Or, and air-lock in the system from not properly re-filling after service (generally overcome by filling as the engine warms up with the heater turned on high heat).
If the engine overheated substantially before the repair was made, you may now have a blown cylinder head gasket, or, a cracked cylinder head. Evidence of this usually is exhaust in the cooling system (testable with proper equipment), Water or steam coming out of the tail pipe when running that continues after warm-up, or, coolant in the engine oil. (when in doubt drain, and watch for coolant, which will come out first as oil will float on it.)
Water pumps generally still work even when the seals or bearings are gone, providing the system is full. Cap will usually cause a delayed overheat as coolant escapes under pressure over a period of days. (all other leaks can do that as well)
Replacing the thermostat is always a good thing to do providing you put it in correctly (properly positioned in bore and spring end towards the inside of the engine)
Additionally, your cooling fans must be working. Electric fan should come on, especially when the engine is overheating. Mechanical fan should lock up and not freewheel again, especially when in overheat.
Aside from system testing, you always need to maintain a 50/50 mix of water/antifreeze. That raises the boil temperature of the system above the 212(f) of plain water....Too much coolant will lower it though.
Any questions about anything you find and don't understand? ASK.

If you put the thermostat in correctly (spring towards the engine) that should be OK. Likely if the water pump wasn't leaking or had a bad bearing, you wasted your $ on that.
If you re-filled it and did not have the heater on high heat, you may have some trapped air in there. But, still overheating says another thing. If you have a blown head gasket, it can pump compression into the cooling system and drive the coolant from the core. It will also overheat. You can have that tested at most any decent shop that will do a hydrocarbon test to find that.I think someone makes a chemical test kit for that but not sure if it's very expensive or not. White smoke from tailpipe will also be an indicator as will be any coolant in the engine oil or coolant on one or more spark plugs. If it turns out that it has a head gasket problem don't stop looking for problems as often a faulty fan or obstructed radiator can cause the initial overheat that caused the gasket to fail.

Generally that smell is caused by an oil leak that is getting on either the exhaust pipe or manifold (doesn't take much to smell). As far as bottle getting low, I've got a 93 that never stays full but only needs coolant in the radiator about once every two months. Been like that for two or three years and has never overheated. I'm sure there is a small leak somewhere, but I'm not driving myself crazy looking for it. Check all hose connections, and look on the ground after being parked overnight...If it's leaking, something will show up. But if the radiator is staying full, just check it when checking oil level.

This might help you as it looks as though you have an electric fan to cool , there should be a sensor on your radiator hoses upper and lower.they are actually switches triggered by the coolant temperature in side the hose. While your Jeep is sitting idle, shut off the AC as it adds to the heat off the engine not to merntion useing more gas. you should make sure both high and low speeds on the coolant fan work. good luck if this does'nt help check out the post, with more, on the 1995 Jeep heating up..

AIR IN COOLING SYSTEM. NEED TO FLUSH COOLANT AND RUST OUT OF SYSTEM AND INSTALL NEW COOLANT WITH A NEW CAP

possible causes of overheating are, dirty cooling system, clogged radiator, bad thermostat. Use only distilled water with a good quality coolant.

still overheating? have your top head checked - warped head, valves, valve seats, etc. You might need to have your engine's compression checked if it is still within specs.