What is causing coolant loss ON 2002 FORD ESCORT ZX2

If your Hyundai H1 2018 model is losing water from the radiator at an alarming rate, even with a new radiator that is not leaking, there are a few potential causes for this issue:

1. Coolant leak: While you mentioned that the radiator is not leaking, there could still be a coolant leak elsewhere in the cooling system. Check for any visible signs of coolant leakage, such as puddles under the vehicle or wet spots on hoses, connections, or the engine. Coolant leaks can occur at various points, including hoses, water pump, heater core, or even the engine block itself. If you cannot identify any external leaks, it is possible that the leak is internal, such as a blown head gasket or a cracked engine block.
2. Faulty radiator cap: The radiator cap plays a crucial role in maintaining the proper pressure and preventing coolant loss. A faulty radiator cap can cause coolant to escape from the system. Inspect the radiator cap for any signs of damage, such as a worn-out gasket or a cracked cap. If necessary, replace the radiator cap with a new one and see if it resolves the issue.
3. Internal engine issue: Internal engine problems, such as a blown head gasket or a cracked engine block, can cause coolant to mix with the combustion chamber or leak into the oil system. This can result in rapid coolant loss without any visible external leaks. Look for symptoms such as white exhaust smoke, coolant in the oil (appearing as a milky substance on the oil dipstick), or an overheating engine. If you suspect an internal engine issue, it is recommended to have the vehicle inspected by a qualified mechanic to diagnose and address the problem.
4. Improper coolant filling or air pockets: If the coolant was not properly filled or if there are air pockets in the cooling system, it can cause coolant loss. Air pockets can prevent the proper circulation of coolant and result in overheating and coolant loss. In such cases, bleeding the cooling system to remove air pockets and ensuring the coolant level is at the correct level may resolve the issue.

Given the significance of the coolant loss and the potential complexity of the underlying problem, it is advisable to have your Hyundai H1 2018 model inspected and diagnosed by a qualified mechanic or Hyundai service center. They will have the expertise and necessary diagnostic equipment to identify the specific cause of the coolant loss and provide the appropriate repairs or solutions.

Vehicles: Any with the above symptoms

A cracked cylinder block will cause either:
(a) motor oil contamination of engine coolant
(b) coolant contamination of motor oil
(c) white exhaust smoke, due to coolant seeping into one or more cylinders.
(d) more than one of the above
(e) all of the above

Oil infiltrating into coolant is easy to see - drain some coolant out through the pepcock at the bottom of the radiator, and place it into a styrofoam coffee cup. Oil droplets floating on top of the green (or orange) coolant are easily seen. Or visualize oil by looking into the top of the radiator through the radiator cap.
Coolant infiltrating into and mixing with motor oil will permanently damage the engine (seizing it up through loss of lubrication), and must be prevented.
A leak from above the front suspension is, as physicians like to put it, "nonspecific", with the most likely cause a water pump seal or hose/hose connection.
A leak from near the fire wall will usually be a heater core hose, or hose connection.
A coolant leak on the same side of the engine as the water pump is a leaking water pump or water pump seal until proven otherwise.

To rule out everythng else, here's the 1999 Honda CR-V Troubleshooting Guide for Coolant Loss/Coolant Leaking:

Priority Action Part Type Cause
1 Inspect Water Pump - Worn, Cracked or Leaking Water Pump, or Water Pump gasket.
2 Inspect Head Gasket - Leaking Head Gasket.
3 Inspect Radiator - Leaking Radiator Hose(s).
4 Inspect Radiator Cap - Worn or Damaged Radiator Cap.
5 Inspect Radiator Hose - Ruptured, Cracked or Leaking Radiator Hose.
6 Inspect Freeze Plug - Leaking Freeze Plug(s).
7 Inspect Intake Manifold Gasket - Leaking, Worn, or Damaged Intake Manifold Gasket.
8 Inspect Water Outlet - Cracked, Leaking or Damaged Water Outlet.
9 Inspect Heater Control Valve - Leaking or Faulty Heater Control Valve.
10 Inspect Radiator Drain Pepcock - Loose, Damaged, or Faulty Radiator Drain Pepcock, or Pepcock O-ring.
11 Inspect Engine (DOMESTIC ONLY) - Cracked Cylinder Block Leaking Coolant into at least one Cylinder, causing white exhaust smoke.

There is a TSB for the PCV hose. The elbows at both ends get holes in the underside that you can't see unless you remove them and look. This is a very, very common issue on the ZX2. You can get a new PCV hose with both elbows for about $30 from the Ford dealership. You only need to remove the air intake to gain access to the PCV hose to replace it.

could be water freezing in your breather and blocking it, or head gasket or cracked head.

Take the radiator cap off and check the coolant level. Don't use the overflow bottle level, it isn't usually accurate. If it is full of coolant then find where the heater core hoses run into the car, just under the intake manifold there are two rubber hoses next to each other, and see if they get hot when the engine is warm. Report back with your findings and I can assist you more.

Loss of coolant,steam, coolant in oil, Oil leak, Loss of compression. Don't forget now engines do have freeze plugs and those sometimes rot out. Fill the radiator and replace the cap run the engine and look underneath the engine bay and inside. If you are losing fluid determine what fluid it is. Don't mistake a blown head gasket for a cracked block. Don't mistake a cracked cylinder head for a cracked block. You can crack a cylinder head just as well as you could crack a block. After you have determined a leak shut the car off. And squeze one of the hoses the coolant will spray or drip out of the crack or hole.
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Sounds like you have a faulty head gasket or maybe a cracked head.This can cause overheating and the check engine light to come on.The code for the o2 sensor is probably caused by coolant getting into the exhaust system and coating the sensor.The coolant fan may work but it cannot remove enough heat from the rad to make the engine cool off.Try some engine coolant stop leak to see if it will help.This maybe only a temperary fix.Let me know if you need more.MOE

the coolant is probably coming from your water pump and leaking down the block try to see if it is wet behind the water pump if so you need to have it changed or one of your hose clamps that connect to your heater core may be loose

This CODE is Indicating that ENGINE COOLANT TEMP is NOT Reaching TEMP HOT Enough to >CLOSE LOOP < This is when ECM takes over ALL ELECTRONIC CONTROLS, . It Basicly Points at A Coolant Temp Sensor that is Faulty or Thermostat that is RATED too LOW. Engine Must Reach 200 - 220 degrees

the cooling drain plug is under the front of the car just under bumper and under the trim on the driver side but look to see if the cooling is coming from your intake gaskets are a heater hose