Engine overheating

Check coolant level and have system pressure checked for a n internal leak. also make sure your electric fans are coming on. This guide can help us fix it.

https://www.2carpros.com/articles/engine-overheating-or-running-hot

Please run down this guide and report back.

Then it may have a fan clutch so check that it should lock up when it gets hot. If you have one when engine gets hot it should be very hard to turn or not at all. If it does it's probably bad. Also check for cold spots in radiator if you feel any the rad is bad. It shold be the same temp all across. Of course do this with the engine off.

Check to see if fans are on when a/c is on they should be. Then check for a bad radiator, check for cold spots on rad when it's hot. If you feel any then you have a bad radiator.

The reason you get no heat is because the core is filled with air instead of coolant. You may not have gotten all the air out when you filled it or you could have a blown head gasket. We use a vacuum fill tool to get all the air out.

No, it wouldn't necessarily be mixing with oil. The most common type of head gasket failure is combustion gases getting into the cooling system which creates superheated air in pockets. Your heater core could be plugged but the only symptom would be lack of heat but not any overheating. You can try removing both heater hoses and flushing it in both directions with a garden hose under pressure.

Have you checked if the radiator fan is turning on? If it is, the next step is to have a chemical test performed at the radiator to check for a leaking cylinder head gasket.

You're kidding, right? You expect me to answer your question but you refuse to provide any information? Did you even bother to read my reply?

This is like calling my doctor and telling him "I'm in pain". He has no clue if I have a hang nail, I cut my foot off with a chainsaw, or my ex-girlfriend came back! You can be sure I'm going to have to provide some details and answer some questions.

Now, if the radiator fan is not turning on, the engine will overheat at low speeds. It will not overheat at highway speeds because natural airflow is more than sufficient.

If the fan is running properly, the engine can still overheat if a cylinder head gasket is leaking. Combustion gases can get into the cooling system where they will pool under the thermostat and prevent it from opening. Thermostats have to be hit with hot liquid. They won't open in response to hot air. Replacing the thermostat won't solve that problem because it isn't the cause of that problem.

The inoperative fan and a leaking head gasket are the two most common causes of overheating. You replaced the parts that are least likely to cause overheating. Once you check the two things in my first reply, we will know how to proceed. Until then, anything is just a guess.

You don't need a fan that's larger than the original, but more importantly, how did you fit that in there? Is the shroud missing? If it is, that will let the hot air go back around repeatedly through the radiator and get hotter and hotter.

Most of these had electric fans, and since you found a related relay, I assume that's what you have. Obviously check that the fan is turning on. If the fan is dead, the engine will not run hot at highway speed.

The next thing is to look at the cooling fins on the radiator. If they're corroded and crumble easily when you rub them, that will reduce their effectiveness at giving up the heat to the surrounding air. The additional clue will be both radiator hoses are real hot.

If the cooling fins are in good shape and not blocked with debris, look for the rubber seal under the leading edge of the hood. That has to make a seal on the core support to prevent air from bypassing the radiator. There also can't be any holes in the core support, for the same reason.

Three times in five years? And an oxygen sensor caused it? I think it's because the driver ran over a pot hole while turning right and driving after dark. That also might only happen three times in five years.

Next time the engine overheats, I suggest someone actually diagnose the problem, or at least install some other random part that's easier to get to. Better yet, put one of the old oxygen sensors back in, then you'll see the engine doesn't overheat.