MY NISSAN QD32 ENGINE IS OVERHEATING.I HAVE CHANGED THE FOLLOWING PARTS BUT THE PROBLEM IS THE SAME;WATER PUMP,RADIATOR,CLUTCH FAN,CYLINDER HEAD GASKET AND SKIMMING OF THE HEAD.WHAT COULD BE THE PROBL

If your 2004 Infiniti G35 is still overheating after replacing the thermostat and cooling sensor, there may be a few other issues that could be causing the problem:

1. Radiator blockage: The radiator may be blocked or clogged, preventing the coolant from flowing through it properly. This can cause the engine to overheat. To check for a blockage, visually inspect the radiator for any obstructions or debris, and flush the radiator to clear out any buildup.
2. Water pump failure: The water pump circulates the coolant through the engine and radiator. If the water pump fails, the coolant will not circulate properly, and the engine can overheat. Check the water pump for any signs of damage or wear, and replace it if necessary.
3. Fan clutch or electric fan failure: The fan clutch or electric fan is responsible for cooling the radiator when the car is idling or driving slowly. If the fan clutch or electric fan fails, the engine can overheat when the car is not moving. Check the fan clutch or electric fan for any signs of damage or wear, and replace it if necessary.
4. Head gasket failure: If the head gasket is blown, coolant can leak into the engine cylinders, causing overheating and other problems. Check the head gasket for any signs of damage or wear, and replace it if necessary.

As for the no heat issue, it's possible that the overheating has caused damage to the heater core or other components. It's also possible that there is air trapped in the cooling system, preventing the coolant from flowing properly through the heater core. Bleeding the cooling system may resolve the issue.

If you have already checked the radiator, fluids, thermostat, and thermo fans and your 1996 Hyundai Lantra Sportswagon is still overheating, there could be other issues causing the problem. Here are a few other things you can check:

1. Water pump: The water pump is responsible for circulating coolant through the engine and radiator. If the water pump is not functioning properly, it can cause the engine to overheat.
2. Head gasket: The head gasket seals the cylinder head to the engine block. If the head gasket is damaged or fails, it can allow coolant to leak into the engine, which can cause the engine to overheat.
3. Cylinder head: If the cylinder head is cracked or damaged, it can cause the engine to overheat.
4. Engine block: If the engine block is damaged or has a crack, it can cause the engine to overheat.
5. Clogged radiator: If the radiator is clogged with debris, it can prevent the coolant from flowing properly and cause the engine to overheat.

To determine the cause of the overheating problem, it will be necessary to perform a thorough inspection of the engine and related components. If you are unable to locate the source of the problem or are not comfortable attempting to fix it yourself, it is recommended to have the vehicle inspected by a professional mechanic.

chek if the electric fan is turning on when the ac is turned on

Check your thermostat, could be locked/closed and won't let water circulate through the engine block. Also make sure your radiator fan is working, after you start you car and the engine reaches the proper temp, your radiator fan should kick in to cool the engine.

Bad news is the air bubbles are actually exhaust gases entering your coolant, you have a blown head gasket, and or bad head, which is also the overheating concern.

could be a number of things, 1. water pump not working 2. Thermostat stuck (replace if its boiled) 3. air lock in system. 4. Head gasket. 5. cracked head/block. I presume you have checked that you belt is not broken, are there any signs of leaking around the waterpump? if there are, change the pump, If the engine has overheated, change the thermostat. these are the most common things, other than these 2 it is going to take further examination for cylinder head problems or blocked water ways. Go for the thermostat first, its probably the cheapest part to replace, and see if that cures your problem.

Assuming this is a 460 Ford Big Block:

REMOVAL

-Drain cooling system.
-Remove drive belts.
-Remove bolts attaching fan shroud to radiator.
-Remove fan blade from fan clutch and remove fan shroud.
-Remove fan clutch and water pump pulley from water pump.
-Remove four bolts and one nut attaching A/C compressor mounting bracket to cylinder head and water pump. Do not remove A/C compressor or power steering pump from A/C compressor mounting bracket.
-Pull A/C compressor mounting bracket forward to remove from stud on water pump.
-Remove bolt attaching generator adjusting arm to water pump. Remove four bolts attaching generator mounting bracket to cylinder head, cylinder block and water pump.
-Remove remaining water pump attaching bolts and remove water pump from engine front cover.
-Remove water pump cover from water pump. Discard water pump housing gasket and water pump cover gasket.
INSTALLATION
-Remove any gasket material from water pump cylinder front cover and separator plate mating surfaces.
-Position new water pump housing gasket and water pump cover gasket coated on both sides with Perfect Seal Sealing Compound B5A-19554-A or equivalent water-resistant sealer meeting Ford specification ESE-M4G115-A.
-Position water pump and water pump cover onto engine front cover. Install bolts and tighten to16-24 Nm (12-18 ft. lbs.).
-Install generator mounting bracket to cylinder head, cylinder block and water pump with four attaching bolts. Install generator adjusting arm to water pump with one attaching bolt. Tighten 7/16-inch bolts to 54-71 Nm (40-53 ft. lbs.) and 3/8-inch bolts to 41-54 Nm (30-40 ft. lbs.).
-Position A/C compressor mounting bracket over water pump stud and secure to cylinder head with four bolts tightened to 54-71 Nm (40-53 ft. lbs.) and secure nut to water pump to 41-54 Nm (30-40 ft. lbs.).
-Install water pump pulley and fan clutch to water pump hub with four bolts. Install fan blade to fan clutch with four bolts. Tighten water pump pulley, fan clutch hub bolts, and fan-to-fan clutch hub bolts to 16-24 Nm (12-18 ft. lbs.). Install fan shroud.
-Install drive belts.
-Fill and bleed the cooling system.
-Start the engine and check for leaks

It sounds like water pump may be your problem. It circulates a 50/50 mixture of glycol (or some form of) and water through the engine block and cylinder head and back through the radiator. In the radiator the mixture is cooled when air passes over the fins of the radiator. This is accomplished by driving or a mechanical/electrical fan when stationary. The water pump also circulates the mixture through the heater core giving the car heat. If the water pump is not circulating the water back to the radiator to cool, it will overheat. More heat is caused by the engine when driving (much less heat when idling), hence the overheating while driving.
I hope this helps and good luck!

1 Inspect Cooling System Mix Coolant level low or flow is restricted. 2 Inspect Belt Incorrectly routed, adjusted, tensioned, missing, or worn water pump belt(s). 3 Inspect Oil Pan Gasket - Performance Ruptured, cracked or leaking radiator hose. 4 Inspect Radiator Cap Worn or damaged radiator cap 5 Inspect Thermostat Thermostat stuck closed 6 Inspect Fan Blade Broken, missing, or defective fan blade(s). 8 Inspect Water Pump Damaged, worn or leaking water pump. 9 Inspect Intake Manifold Plenum - Perform Leaking water pump gasket. 10 Inspect Cooling Fan Control Faulty cooling fan control or circuit. 11 Inspect Cooling Fan Switch - Radiator Faulty radiator cooling fan switch or circuit. 12 Inspect Engine Temperature Sensor Faulty engine temperature sensor or circuit. 13 Inspect Temperature Switch Damaged or faulty temperature switch or temperature switch circuit. 14 Inspect Fan Clutch Worn, loose or faulty fan clutch. 15 Inspect Ported Vacuum Switch Damaged, leaking, or faulty ported vacuum switch. 16 Inspect Radiator Obstructed radiator core or radiator cooling fins. 17 Inspect Head Gasket - Performance Head gasket leaking coolant into cylinders

2 Inspect Belt Incorrectly routed, adjusted, tensioned, missing, or worn water pump belt(s). 3 Inspect Oil Pan Gasket - Performance Ruptured, cracked or leaking radiator hose. 4 Inspect Radiator Cap Worn or damaged radiator cap 5 Inspect Thermostat Thermostat stuck closed 6 Inspect Fan Blade Broken, missing, or defective fan blade(s). 8 Inspect Water Pump Damaged, worn or leaking water pump. 9 Inspect Intake Manifold Plenum - Perform Leaking water pump gasket. 10 Inspect Cooling Fan Control Faulty cooling fan control or circuit. 11 Inspect Cooling Fan Switch - Radiator Faulty radiator cooling fan switch or circuit. 12 Inspect Engine Temperature Sensor Faulty engine temperature sensor or circuit. 13 Inspect Temperature Switch Damaged or faulty temperature switch or temperature switch circuit. 14 Inspect Fan Clutch Worn, loose or faulty fan clutch. 15 Inspect Ported Vacuum Switch Damaged, leaking, or faulty ported vacuum switch. 16 Inspect Radiator Obstructed radiator core or radiator cooling fins. 17 Inspect Head Gasket - Performance Head gasket leaking coolant into cylinders here is a list of things to check Shaun