Need help! Gas engine overheating. Cannot resolve.

RockAuto is a reputable supplier and the other webpage also seems legitimate. However I don't know why you would buy from two different suppliers; could you not return the first failed pump under the 12 month warranty?

 

I did but they didn't have one in stock so I had to order from rockauto

 

A few other questions for you to consider:

1. Does the check engine light come on, or other warning lights? If yes have you retrieved the diagnostic trouble codes? If any DTC are logged maybe that would give you further clues about your engine's problems (there may be other issues which accompany the overheating issue.)

2. Which engine wiring harness are you using: the original G3 harness or the G4 harness?

3. The Toyota part number for the G3 engine coolant pump differs from the G4 engine coolant pump. Might there be some subtle differences between the two pumps with respect to the wiring harness connectors etc., which is contributing to the overheating? I suggest you obtain the factory repair manual electrical wiring diagrams for your model year and compare to the model year that the G4 engine was associated with. Carefully study the wiring diagrams associated with the connections between the engine ECU and the engine coolant pump to see if there are any differences with respect to pin numbering etc.

4. What evidence did you find to indicate that the three engine coolant pumps failed?

5. If you have good evidence for #4 above, what evidence do you have that the pumps ever worked? (In other words, maybe a wiring harness fault is the issue and not the pump?)

 

Maybe glance through this thread. One post mentions a guy who went through a few pumps and ended up finding that the electrical connector on the car harness had some problems. It was a good read.

Water pump failure Symptoms | PriusChat

 

@Patrick Wong
1. No engine light. I keep checking the coolant temp on my app and pull it out or slow down as soon as it reaches 230F or so.
2.I'm using Gen3 wire harness
3. I'll find diagram and see how they both compare but based on what I saw in vedios from Fix That Prius, this should be least of concern
4. All 3 times I heard weird noise coming out of it and found that it is not rotating as it should when I pulled them out. They were hard to spin and lost magnetic resistance
5. I felt Pumpnworkwd because I got proper heat in cabin and saw coolant temp going up and dropping down as it should.

@TMR-JWAP
Thank you. I'll go through it.

 

1 gallon = 4 quarts. So you added about 5 quarts total.


moto g(7) power ?

 

I would say about 6

 

Just a pipe to allow it to flow freely through when water pump pumps...

moto g(7) power ?

 

So this model year has exhaust gas that heats the coolant? Is that system working properly? You don't want that working when engine is under high load. (I guess that it's 50/50 your car has this).

moto g(7) power ?

 

I don't know!!

 

How's your thermostat? If it fails closed you could be baking the pump?

 

Having the same problem with my 2013. High temp light comes on after getting on expressway. Pull over immediately and let set a couple minutes and it is fine. Had two instance where reservoir overflowed, but last time did not. Took in to Toyota dealer and they claimed water pump showed an over revolution code and a misfire on cylinder 2, although car has never misfired and never had a CEL. They purged the system of air. They said the water pump and t-stat were working as of when they had it. They also pressure tested and it held pressure. They removed plugs and no coolant in any of the cylinders. Sent me home. Did the exact same thing a couple days ago, but coolant reservoir did not rise. Coolant level remained the same. Has 175k and has been trouble free. Have not had EGR cooler cleaned. I see you are in Michigan-we are over by Grand Rapids. Any repair/diagnosis recommendations or repair shops you like?

 

This is in regards to overheating issue after swap. Huge thanks to @cnc97 and @Ragingfit

Two things need to be made sure.
(1) @cnc97 - The important thing about the jiggle pin (in thermostat), or hole left behind when you cut it, it must be up, not down. Otherwise, the purpose of it being there is defeated.
(2) @Ragingfit -

Sergiy Kovalevych10 hours ago
Installed a 2016 prius engine in to 2010 prius. Burned two electric coolant pumps(an impeller stuck melted), because of overheating of the engine. The coolant system was creating air bubbles. The problem was very difficult to figure out. The solution was very simple. The level of an expansion tank hose ,which goes from the connection on the engine head to expansion tank must be only up!!! No sag or dip of the hose. By the correct hose leve the bubbles will freely come out to the coolant expansion tank, will not go back to the engine head or to the cabin heating coil. Driving vehicle around 20000 miles (1 year). Didn't have any problems anymore. Good luck guys.
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Sorry for the late reply. A PM would be a better way to Have too many PC alerts.

I'd stay clear of Toyota of Grand Rapids. Terrible service for my wife's new 2016 Prius including oil changes paid for but not completed.

Kool Toyota on Alpine may be good. I only did the ECU reprogram recall there.

I do my own oil changes and engine work.

I'd get the EGR cooler and intake manifold clean ASAP. If coolant hasn't dropped you may be lucky and avoid a bad head gasket. IMHO, If you can't do it yourself just replace them with new parts.

 

The sand pounder with that though: for all the Exhaust Gas Recirculation components, and the intake manifold, you’re looking at about a grand, just for parts, then there’s the labour. And all of it readily cleanable. And this is something that ideally should be done every 50k or so, maybe 100k for the first time. But even that’s pushing it, at least that’s my take. The clogging is gradual, doesn’t happen all at once at 100k. And the effect of clogging is an engine gradually running hotter.

if you do go the rolls Royce route, at least keep the old parts, and clean them, for next time.

 

The whole point of the engine's thermostatically regulated cooling system is to adapt all the time to differences in speed, load, timing, mixture, outside temperature, all the variables that affect heat produced in the engine, and keep the resulting temperature stable.

To talk sensibly about the EGR would require talking specifically about instantaneous temperatures of the mixture inside the combustion chamber, and of course those temperatures swing very widely over the course of every cycle of the engine, from intake to compression to power stroke to exhaust. The point of EGR is to reduce the peak temperature those gases reach during the hottest few milliseconds of every cycle, because that's where NOx emissions are produced, which works out to a much smaller difference in the average temperature there, or in the amount of heat transferred from those gases to the cylinder walls and head. In one of the innumerable other threads going on about EGR there are some graphs of those mixture temps, graphed by crank angle through the cycle, for different EGR flows, taken from published papers on engine design with EGR.

But of course that doesn't result in the engine "running hotter"—the coolant temperature you see on a ScanGauge, or an overheat warning—one bit. The same cooling system and thermostat that keeps that temperature stable whether you're winding down a shady street or climbing an uphill in desert sun will keep it just as stable under the variations due to EGR flow.

There could be accurate things to say about clogged-EGR effects on how the engine operates, but "engine gradually running hotter" is just way too oversimplified to qualify.

 

I’m maybe your shill, lol?

 

So it's been a while but I have an update. I took it to the dealership in January and had them flush the coolant and refill (my thinking at the time was perhaps I had air pockets that I could not find) - didn't help.

So let's review:
New water pump
New thermostat
New radiator
Backflushed heater core
Air purged by dealership

I'm starting to think my car is cursed. The weather here has been anywhere from 30-60 Fahrenheit, so I haven't really had any trouble driving short distances, or driving under 40 mph. It's really above 40-50 mph that it overheats, and then only after 3 or 4 miles. Having winter temps has helped some, but as soon as spring rolls around I'll be back in the same boat.

My last idea is perhaps it has something to do with the valve on the exhaust heat exchanger. I'm not knowledgeable enough on it at the moment to say one way or the other, but I honestly can't see what else could possibly be the problem. The rest of the coolant system is essentially brand new.

 

@Jacob Bonner-. I tried to read your posts in another thread. This is the same Gen 3 with a HG issue? It hasn't been replaced? Put a HG bottle in if not yet...

moto g(7) power ?

 

I replaced the 2012 engine (head gasket failure) with a 2017 engine. It's overheating despite replacing most of the coolant system.