Engine is overheating?

Unfortunately, this may be a head gasket. I have seen a number of times that the head gasket allows combustion chamber gases into the coolant when it gets hot.

The way to test this is when it starts to overheat you need to test for combustion gases.

I hate to say it but normally these hard to find and duplicate overheating normally always comes back to the head gasket.

https://www.2carpros.com/articles/head-gasket-blown-test

Let me know what you find and we can go from there.

Hi,

It is not uncommon for an engine to get hotter when it is turned off however, it should not actually overheat when it is off unless it was on its way to overheating while it was running. The temperature goes up because the coolant is no longer moving so the coolant gets hotter and the temperature sensor is picking that up. Then starting the vehicle gets the coolant moving again and the gauge will come down.

Did the vehicle actually overheat?

Ok. That makes more sense. I suspect you have an air pocket. I would use a funnel kit like the one pictured below. Make sure the fans are working and then hook up this funnel using the correct adapter that is provided and put some coolant in it. Then start the engine until it gets hot. Then run it until all the air bubbles come out and it is not pulling in any more coolant. Just make sure the funnel is not empty. However, don't put more than the bottom 25% of the funnel with coolant because it could overflow.

As for the leak, we need to pressurize the system to see if we can find the leak. Here is a guide that will take you through the basics of a leak.

https://www.2carpros.com/articles/car-is-leaking-coolant

If we don't fix the leak then I would not start with the overheating. Basically it will be a never ending cycle.

If the leak is now repaired, then we need to use the funnel. Let me know if this doesn't makes sense.

Okay. That is great. Once repaired we need to retest and see where we are. Clearly replacing the radiator will require a drain and fill of the system. Just make sure we use one of those funnels that I showed before and that will prevent an air pockets so maybe we will catch any other problems with that. Thanks

Make sure none of the radiator hoses are collapsing when the engine gets hot. Also, a bad head gasket. HAve you checked engine compression? Also, are the cooling fans coming on properly?

You may have an internal leak into the cylinders. You can get a head check done, this is a quick and simple chemical test to determine if combustion gasses are entering the cooling system. Most mechanics can do this test as you wait.

The fact that the temperature jumps up fast points at a head gasket leak, as does it using coolant with no sign of an external leak. Combustion gas test is an easy test, you can even DIY it with a rental kit. It uses a fluid that reacts to the gases present in engine exhaust, none of which should exist in the cooling system. The fluid starts as blue, you draw some of the "air" that is in the cooling system up into the fluid, if it turns yellow you have a leak.
https://www.2carpros.com/articles/head-gasket-blown-test

If coolant is not leaking onto the ground, you should most likely not need a new radiator. As for the engine, is it running yet? If it runs at normal temperature at highway speeds, I don't why they would say you need a new engine. You might want to get a second opinion.

Caradiodoc

Hi
Was any repair done before the problem? You maybe hearing the heater core as coolant passes through. Was new radiator cap installed? Does it overheat at each startup? After is it O.K?
Let me know
Thanks for donate

Hi
Have your mechanic check oil? And check for coolant in cumbustion chamber.

That's running somewhat hot. Have you tried flushing the cooling system?