Radiator Coolant Loss (2020 CX-5)

[Pitter]

Well many thanks to those who have offered very helpful suggestions to date. The replacement part has bee ordered but the import delay could be another two week. I the photo it is apparent where the source of the leak is. Probably won't work due to pressure or heat or both but for the heck of it I'm going to try applying epoxy to the apparent source of the leak in the image to see if I can put the issue on hold until the part arrives. If the epoxy fix seems to be holding in the next days I will be tempted to make the multiple hour trip next week in my car instead of a rented Hyundai Accent or such!

 

[Silly Wabbit]

If it's only a leak then it shouldn't explode everywhere. If it's pressurized and it the hose gives then you'll be stranded. I wouldn't recommend this gamble

 

[Pitter]

Thanks yes I've decided against it.

 

[N7turbo]

There shouldn't be enough pressure to burst a hose, or it would have happened long ago.

If concerned, you could use RTV which in case it is pressurized, will fail before anything else.

 

[200955]

My bad, I haven't paid much attention to temperature as it was always fine but recently while parked for a moment the engine started running at a high RPM. Checking the gauge I saw the needle was definately higher than normal though well below the red zone. The next day with the engine cold I found I needed to add maybe half a quart of antifreeze. I also noted that antifreeze had splashed out on lower components at some point with green coloring on them but not currently. I'll have to pin that down but it seems the engine sensors know when things are getting too hot and crank up the RPM to cool it down. A new one for me.

I doubt very much that the head is cracked but running an engine over heating will definitely cost more than a water neck or hose. If there is leakage from the cylinders to the cooling system, you will probably see air bubbles in the overflow bottle. A simple test is to hand pressurize the cooling system and see if the pressure holds. I would suspect the electronic thermostat is the issue. If it doesn't open flow is restricted and temperatures rise significantly. Failing electric fan and debris on
the AC condenser will also cause high temps, higher than normal pressure and leaks that would otherwise not happen. When they know you're desperate and ill informed dealers can cost you a fortune with little to no argument on your part. Pressurize that system to determine the leak and eliminate a bad head gasket or cracked head. But if the issue is covered under warranty let the car wizards fix it. And by the way, a high idle is not caused by the cooling system, the AC kick-up maybe, but not cooling. Check those cooling fans!

 

[Pitter]

What is RTV?

 

[HyFlyer]

What is RTV?

Room-Temperature Vulcanizing

A type of silicone sealant

 

[Jmaz]

Here's a sealant that I've used with good success that's stronger than the usual silicone gasket maker/sealer. It's an ADHESIVE sealant. I always keep a tube on hand for unplanned fixes. Also, a windshield sealant is tougher stuff too. An epoxy may provide a strong seal also.

Permatex® Black Silicone Adhesive Sealant, 3 OZ - Permatex®

www.permatex.com