Overheats on highway the coolant will be gone after it cools down. 100,000 miles my radiator holds at 16 lbs 1997 Ford Expedition

My 1997 expedition over heats on the highway. Will jump to H and coolant will be boiling. When finally cooled coolant will be gone. Cap is new,thermostat is month old. Please help I am broke I can not pay for more tows n I live in my car that's now broke down… I don't have a leak because it holds at 15-16 pressure

My car has 100000 miles.
My car has an automatic transmission.

Experienced mechanics share their insights in answering this question :
Hi – overheating with coolant loss at highway speeds can have several causes. First thing to check is that the system is thoroughly bled of all air. Bleed the system with the heater cranked up to "Max" heat and fan speed. Sometimes, bleeding the system with the front of the vehicle raised higher than the rear (or with bleed screws open if so equipped). It’s also possible that the water pump is weak, the radiator is clogged, or a head gasket has failed. Finding where the coolant is going will be instructive also: boiling out, leaking from the water pump, going out the tailpipe, etc. I would recommend a overheating inspection

How to Identify and Fix Common car Problems ?

Our sources include academic articles, blog posts, and personal essays from experienced mechanics :

The most common reasons a Ford Expedition is overheating are a coolant leak (water pump, radiator, hose etc.), the radiator fan, or a failed thermostat. Coolant leak (water pump, radiator, hose etc.)
Why is my car overheating but it has coolant in it? It could be that the coolant concentration is not correct, or you may have a bad thermostat, a failed water pump, broken drive belt, or a bad radiator or radiator fan.
Adding coolant does nothing to address the problem that caused your engine to overheat in the first place, but it often allows you to drive safely to the nearest repair station. “A professional will need to inspect your car`s cooling system,” says Reina. While driving, keep an eye on the temperature gauge.
Leaks are the #1 reason a vehicle begins to overheat. Leaks in hoses, the radiator, water pump, thermostat housing, heater core, head gasket, freeze plugs and a few other things can all lead to problems with the vehicle`s cooling system.
Can you top your coolant up with water? Coolant should only be topped up with water in case of an emergency when the coolant liquid level is lower than it should be. While topping up with water will help you get safely to the nearest RAC Approved Garage and identify any issues, it shouldn`t be relied upon.
If your car is still running as normal even though the engine overheated (aside from the rising temperature), you can turn your heat on while you wait for assistance as this will help to pull heat off the engine and might help to salvage it if possible.
The 1.0 Ecoboost engine also tends to overheat. This is due to the small size of the engine and the amount of heat it produces. The best way to prevent this problem is to ensure your coolant level is topped off, and you have a good quality coolant in your system.
A cooling system leak is the most common cause of an overheating engine. The leak could spring from your hoses, your water pump, your coolant tank, or your radiator itself, so closer inspection is needed if you see that your coolant tank has gone dry. Using the wrong coolant could also get you into trouble.
The 1.0 Ecoboost engine also tends to overheat. This is due to the small size of the engine and the amount of heat it produces. The best way to prevent this problem is to ensure your coolant level is topped off, and you have a good quality coolant in your system.

Relevant Questions and Answers :

the most relevant questions and answers related to your specific issue

Overheats on highway the coolant will be gone after it cools down. 100,000 miles my radiator holds at 16 lbs 1997 Ford Expedition
ANSWER : Hi – overheating with coolant loss at highway speeds can have several causes. First thing to check is that the system is thoroughly bled of all air. Bleed the system with the heater cranked up to "Max" heat and fan speed. Sometimes, bleeding the system with the front of the vehicle raised higher than the rear (or with bleed screws open if so equipped). It’s also possible that the water pump is weak, the radiator is clogged, or a head gasket has failed. Finding where the coolant is going will be instructive also: boiling out, leaking from the water pump, going out the tailpipe, etc. I would recommend a overheating inspection

No coolant in the reservoir. Seen low coolant message. I added 2 quarts of 50/50 coolant. Still getting the message. How much coolant doe it need?
ANSWER : Hi there. For the coolant light to go out, you would need to have the coolant between the low line and the full line for the light to go out. If the coolant is low and keeps on being low, then look for any signs of coolant leaks. You may have to use a coolant pressure tester to pressurize the reservoir to allow the leak to be found.

If you need further assistance with the coolant being low and the warning light being on, then seek out a professional, such as one from Your Mechanic, to help you.

Over heating coolant not siphoning back into coolant over flow tank
ANSWER : Hey there:

It’s common for many mechanics to make the mistake of mis-diagnosing the cause of an overheating situation; especially when they assume it’s a thermostat issue. The problem could be caused by a blockage in the coolant tubes running from the radiator to the overflow tank and back to the radiator. However, it also may be due to air trapped in the coolant lines. I think a good idea would be to contact a different ASE certified mechanic, such as one from YourMechanic, and have them complete a coolant flush, which should remove any blockages in the coolant tubes and may solve your problem.

Can I replace a leaky radiator with a used one or should I get a new Ford radiator?
ANSWER : Hey there, thanks for writing in about your 2008 Ford F-350. I would check to see if the radiator is available aftermarket first. I would not go with a used one, since you never know what you will get. If you cannot get an aftermarket part, then a new one is the way to go. If you end up wanting a new radiator, consider YourMechanic, as a certified technician can come to your car’s location to replace the radiator for you.

Questions about cooling system flush service.
ANSWER : Hi there. i have forwarded your request to our service and sales department, which should be contacting you shortly with specifics to the questions you’ve asked. In general however, a proper radiator flush would include removing coolant from the lower hose connection (not the petcock) and the block. Our mobile mechanics always bring more than enough coolant than what is required, and will use the recommended type of coolant with the correct 50 / 50 ratio of coolant to distilled water. The brands are pretty much all identical in formulation. The critical thing is making sure to correctly bleed the system afterwards, which is something all of our professional mobile mechanics will do after completing this service.

Engine over-heating and Radiator then overflows fluid or steam.
ANSWER : First of all, overheating the engine will damage it. The list of reasons why is long, but here is a partial list of reasons why overheating the engine will ruin it.

The engine oil becomes much thinner at higher temps.
The engine oil can bake on to metal parts
Engines have very tight spaces for pressurized oil to lubricate the parts. When the engine is too hot, these spaces become smaller, or disappear all together.
Gaskets fail easier.
Metal parts can become warped.
You can overheat the transmission by overheating the engine. First of all they are bolted together and share the heat. Second, the cooler lines from the transmission go to the radiator to be cooled. When the radiator is boiling, this cooks the transmission fluid. Too much heat is the number one problem with transmission failure.

Second, there really isn’t such a thing as weakening it, it’s either runs well, or it doesn’t. Considering that the engine is over heating in such a short time and distance, I would assume that the coolant is not circulating. The first and easiest part to check or replace would be the thermostat (as needed). While the engine is running and full of coolant, feel the upper and lower radiator hoses. If one is hot, and the other is not, the thermostat might be stuck closed.

Finally, I believe, based on my gut feeling, that the the water pump has failed. I have seen the impeller that circulates the coolant come off before. When this happens, the coolant does not circulate. It will heat up quickly when it can not reach the radiator. It will then boil. This does not happen at 212 degrees. A 50/50 mix of coolant and water, under 16 psi of pressure, will boil around 260 degrees. This creates extra pressure in the system. The radiator cap is designed to release any pressure over it’s rating into the coolant reservoir. It will quickly overflow under these circumstances. The cooling fan that you hard wired will not do much of anything because the hot coolant in the engine never gets to the radiator, until its too late and boiling. You can confirm this when the engine is hot, the fan will be blowing cold air.

I would not delay having this repaired. Consider having a certified mechanic, such as one from YourMechanic, come by and address your overheating concerns.

Radiator hose from cap to coolant reservoir broke off just below cap on radiator. Can repairs bbeen done without changing radiator? 2010 Nissan Armada
ANSWER : Hello – although this cooling system hose looks much like an octopus, it can be changed without removing the radiator. It does require small hands and a bit of "technique". For assistance, I would recommend a radiator hose service by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.

Possible coolant in my oil but no oil in the coolant. Use about 1 l of coolant per 100km.
ANSWER : Check the transmission fluid. If all testing eliminates the head gasket, cracked cylinder head, etc, it may be a cracked radiator.Transmission fluid is sent forward to the radiator to be cooled. Ir runs into what is typically called the "side tanks" of the radiator. So the transmission fluid and coolant are both flowing through the radiator and kept apart just as the engine oil and coolant are kept apart in the engine by the head gasket, coolant and oil passages, etc. If the tank in the radiator is cracked internally, transmission fluid may actually be forced into the coolant as transmission fluid is under higher pressure than the coolant. Short of a cracked head gasket, cylinder head, or engine block, it’s really the only other source of any type of oil getting into the coolant unless the vehicle is equipped with an engine oil cooler as well.