URGENT - OVERHEAT - Red Triangle & Temp Icon on road trip (Live From Starbucks)

If it is the engine coolant that is overheating, check the serpentine belt (it drives your ICE coolant pump) and your thermostat (it may be stuck closed).

JeffD

 

I'm not sure what you expected "3 hours at 80-90mph over hills, in a heavily loaded Gen 2 Prius with 230k miles, in 90 degree weather" - that's borderline dumb.... hopefully you didn't spray yourself with piping hot coolant. I don't suppose you have an OBD2 adapter?

 

That belt drives the water pump... so no way to cool the engine without it. You'll likely damage the engine pretty quickly.

 

If you want to replace the whole engine you can keep going with no belt because who needs a water pump to keep the engine cool right? I mean if you're driving hills at 80-90mph in a heavily loaded Prius its not like you car or your person are going to be around much longer anyways.

But if you change your mind and fix the belt... And decide to drive at safe speeds...

Get one of these devices: Hybrid battery diagnostic and repair tool for Toyota and Lexus So you can read and clear codes, monitor hybrid battery health via Dr. Prius app. Also using OBD Doctor app will give you an RPM reading and engine is most efficient climbing hills at 3500 RPM. These are the data points that define how fast you can drive. And road conditions and the cost of a 90mph speeding ticket should be considered too.

 

Or already did damage the engine...

 

Foregoing the snark....

1. Yes, you need to replace the belt. The belt drives the water pump, without which the engine isn't cooled.

2. Can you turn the water pump by hand? If the belt just failed from age and the pump turns smoothly, a new belt is probably the solution. If the belt is shredded because the pump seized up, then the pump should be replaced, lest it simply shred the next belt.

2. If you noticed pressure being relieved at the radiator cap, the cap was probably just doing its job with an overheated car. I am not seeing any obvious reason to condemn the cap.

3. Replacing the thermostat may be prudent. Serious overheating can damage a thermostat (the expanding wax that makes it open expands too much, and spooges out from where it needs to be). The result can be that even after fixing what originally caused the overheating (no water pump), the car may continue to overheat because now the thermostat has been killed.

Possible get-me-to-safety desperation option: a Gen 2 Prius has a separate electric water pump just to serve the heater. You may be able to get some cooling of the engine by opening the windows and running the heater full blast. (However, the electric pump might not normally run when the engine is running, because the belt-driven pump is assumed to take over then. If you have Techstream, you may be able to force the electric pump to run.) This will not have nearly the cooling capacity for 80 MPH jaunts over hills, but it may reduce chances of damage while driving very conservatively to a place where repairs can be made.

 

Where might you be currently, as there may be another member that could help. Replacing the $15 belt is fairly simple, though sometimes the bolt on the belt tensioner can be a bit tight. Small hands will help get it on. Shouldn't take more than 15 mins once the parts in hand.

 

Glad that things worked out! Sorry about my "borderline dumb" comment - I've done worse!

 

Really?
I drove 10 hours and back with my kids two weeks ago, no problems at all. Why shouldn’t the car do that? That’s what cars do. In fact, they often run far higher mileage when used nonstop like that; it’s far less wear than stop-and-go.

 

The faster you drive the less likely you will survive a collision... Cars are well designed for surviving impacts below 40mph but deadly at higher speeds. So if you're about to crash at freeway speed your life and your family's lives depends on you eliminating 20-30mph before the impact. But if you regularly drive at 80-90mph you're going to have to reduce your speed by 40-50mph to survive the impact.

What I like about Prius is I can drive 13 hours in a day on the freeway in the slow lane and because its a Prius no one is surprised or bothered by fact I'm just barely faster than the slowest vehicles.

 

Well I for one would chose "Not," to drive a heavily loaded Prius up and down hill's at 80 to 90 mph, in 90 degree heat? But that's just me.

 

Have you ever driven a Gen 2 Prius under those conditions? Uphill, 80-90 mph, 90 deg weather so likely AC blowing, and heavily loaded.... If you owned a Gen 2, you'd understand. I'd say that there is a decent likelihood that any of us would experience the same fate under those conditions.

 

Lol... You sound like a Prius driver!

 

A Bad belt can happen on any car. Were it not for that it sounds like you'd have not had any issue's anyway?

But that aside the Gen 3, despite it's other numerous "issue's," has a bigger ICE and a better "tranny/diff." More "over/drive(ish)" if you will. It makes it easier on the motors at silly speed's.

So it really would not be a fair comparison anyway? Still people do stuff. I heard the Gen ll, can do a 110 mph on a straight? I don't know? But ... I can say "Downhill," our 2005 did 101, mph? I was stunned and most of that "speed," was generated with light to no throttle? And under those condition's, it was getting 99 mpg at 101 mph. Weird little car's really? They are capable of more than people "assume?"

Still under high ambient temps, 95 degrees plus? Our 2 Gen, is not to happy "apparently?" The Battery pack get's pretty hot? Over 120, after a hour or so? But I am not pressing it, in high heat, at high speed for an extended period of time? I'd drive at night, if this is something you have to do?

 

The Gen2 was software limited to 104 MPH.

JeffD

 

LOL, well I read 110 mph "somewhere?" But having been there and done that. My 2005 did not even break a sweat at 101 mph downhill. I most likely hit 80 mph at the start of the hill (Passing a tail gating SUV A-Hole!) at the start of the hill? But I did not need much in the way of throttle from that point on? At that point it did 101 with no throttle.

And I certainly could have done better than 104 or even 110 mph without effort (downhill.) But I am not interested in getting a "Felony Speeding Ticket," in a Prius? That would be "embarrassing as well as expensive!"

Now on a flat level straight, then maybe it won't exceed 104 mph? But add "Gravity," to the equation? And our 2005 would blow by 104 and exceeding 110 felt not off the table? It was pretty stable really? Aside from the speedometer you'd certainly not have know it was going that fast? I doubt a "software fix," would have slowed it down? But hey, I don't know?

 

What does that speech have to do with mechanical reliability?