Need help! Gas engine overheating. Cannot resolve.

Strangely enough, I have never had issues with bleeding these systems. The way I do it is that I fill the system, then I allow the car to idle in maintenance mode for 30-45 min (until the ECT reads higher than 180) with the cap removed. About 1/2 of the time I fill the system using my vacuum fill tool, but on this application, it doesn’t make a huge difference.

 

The grill is in FRONT of the radiator; two different things.

So....what drives the water pump then. Electric or gear ??

 

Maybe not.
If the water coming into the radiator is "really hot".....like 200 F.....then the water leaving the radiator probably should be 100F or a bit more.
It still sounds to me like you don't have proper water flow.

Edit: Moot point now. Glad you got it fixed.

 

check and clean your EGR pipe. engine is too hot because EGR flow is low due to a lot of soot block the pipe

 

Thanks for posting. I have a very similar problem. While cleaning the intake manifold, I removed the throttle body, dumping antifreeze. When I reassembled it, I ran maintenance mode & refilled the coolant. For weeks, It's been getting better MPG, but one long hill causes it to overheat. The heater blows warm air, but not hot. The reservoir has bubbles while hot, but in the morning, it settles to the normal full level. I plan to elevate the reservoir, etc.

By the way, I agree with Laur. When I removed my EGR cooler for cleaning, it was completely clogged with carbon. I've read that it can cause overheating & weaken the head gasket. It won't improve your mpg or acceleration, but it will help the life of your motor. It's made of stainless steel, so you can soak it in Drano or Easy Off.

 

You can pull off the throttle body without disconnecting coolant lines, get it out of the way enough to remove the intake manifold.

Similarly with the EGR Valve/Cooler removal, I found draining a couple of liters of engine coolant (at the radiator drain petcock), the coolant level in the system dropped lower than the complete EGR system, and you pull of the EGR hoses without any spillage. There's a few tablespoons of coolant trapped at the rear corner of the cooler, which you can just pour out into the rest of the drained fluid.

When everything is back together, pouring the coolant into the reservoir, the level will be back to normal with a day or two of driving. If you've got the engine coolant bleed valve (2010, 2011), leave it open till coolant appears, while refilling, then quickly close. With later model years that nix the valve, just leave off the topmost hose on the egr, till the fluid starts appearing, then reconnect quickly before filling further.

 

Drano? That's a good idea too. I use easy off. It was fast and effective.

 

In another thread asking about the purposes of cooled EGR, it turned out that MPG improvement is one of them, after all.

 

Right. That's why Prii have it, when they could've met emissions standards with regular EGR.

 

Hello Prius lovers.
I’ve been having problems with overheating on my 2012 Prius V. Overheating issue started this winter. Car started with no heat in the cab. I’ve tried purging the cooling system. And still overheating I get the flashing temp symbol.
I’ve noticed that when it overheatsthe heat blows cold. Also I checked the water pump and fans they come on and off. Both water pump and fans come on and off. I would think that fans and water pump should keep running constantly. Let me know if you guys have some input please

 

Broken water pump impellers are a fairly common failure and you can't really see that from the outside.
When that happens, the water mostly stops circulating.......through the engine AND through the heater core.

 

I had spare water pump and Tstat. Both have been replaced. I compared it to my other Prius V and on that one the water pump stays running constantly with heater on.
Does anyone know what controls the water pump to stay running constantly?

 

And you didn't mention that in your FIRST post......why exactly ??
The pump likely should run continuously when the engine does......but the fans may not.

 

@gus1203 Did you have any luck with the overheating? I have a 2013 Prius V with 170K on it. It just recently started lighting the overheat lamp and spraying a bit of coolant out of the reservoir pressure release cap. At about 130K the head gasket blew and I replace it myself and at the same time thoroughly went through the EGR. Past 40K miles have been flawless until now. It only overheats at highways speeds (over 70) and with a moderately heavy load (150lbs for me and 300lbs of cargo). No leaks anywhere and no codes at this time.

 

On highway speeds overheating, might indicate to me a failing electric fan, or a clogged radiator/condenser fins(insufficient incoming air). The engine electric water pump might be low on pumping. Check all those, before opening up the top cylinder

 

Trace,
I’m still fighting with the same problem. Heat comes on and off. Light starts flashing at highway at about 60 mph. Then it stays on constantly If I don’t slow down. Fans work, I’ve swapped water pump and tstat with used ones. Nothing seemed to help. Any suggestions are greatly appreciated.

 

If you have a compressor, you can blow out the radiator and condenser. You can also do it with a water hose.
Are you sure the fans are spinning the correct way???
The fans are not even needed if you are driving 70mph.
I take it the thermostat & water pump you installed are KNOWN good and functioning correctly?
Did you use the correct coolant? KNOW you got all the air out of the system?
If it wasn't electrically controlled, I'd say your timing wasn't advancing.
I would "guess" you have a clogged radiator, or hose, or both.

 

Radiator was replaced new. New temperature sensors. I checked tstas in boiling water with digital thermometer and are in specs also water pump runs fine. Also replaced water pump relay. This is so frustrating. I hope my engine is not damaged. Engine has about 130k miles