Longo Toyota tells me Prius overheating is *normal*!?

What a crock o' sh!t. They screwed up the repair. Take it to another dealer who knows what they're doing and see whether
1) the problem was created by the accident that also created the need for the body work, and Longo failed to find and fix it the first time,
or
2) Longo created it in the course of the body work, and Longo failed to find and fix it when you took it back
(Note to self: never use Longo Toyota.)

 

What is your odometer reading and was the engine coolant replaced when the body repair work was done?

It definitely is not normal for the Prius to overheat - southern CA weather will get much hotter before the spring and summer seasons are over. I want to confirm which warning lights came on:

• red triangle master warning light
• red thermometer icon

Is that correct?

If you are up to doing a cooling system inspection yourself, I suggest the following:

Check the fluid level in the translucent overflow tank near the radiator, and (when the engine is cold) check the level in the radiator by removing the cap.

To access the radiator cap you have to remove the large black plastic panel that runs across the front of the engine compartment. It has several fasteners; rotate each fastener counterclockwise using a Phillips screwdriver while exerting upwards pressure on the panel near the fastener. This will cause the fastener to pop out.

When the car is operating in hot weather can you notice whether the two electric fans that are mounted on the radiator are running?

To test this, drive the car until the engine is warm, then park the car and enable inspection mode. (To enter this mode, make the car IG-ON (not READY) where the instrument panel warning lights come on. Fully depress the accelerator pedal twice while in Park. Then shift to Neutral and fully depress the accelerator pedal twice. Then shift to Park and fully depress the accelerator pedal twice. Then depress the brake pedal and start the car by pressing the POWER button.) The hybrid vehicle warning light will come on and the engine will run continuously.

The cooling fans should run whenever the engine coolant temp reaches or exceeds 100 degrees C, at a relatively slow speed as the fans are connected in series across the 12VDC bus. When the air conditioner compressor is running, the fan speed should substantially increase as each fan will be powered by the 12VDC bus.

After you are done with your check, turn off the car to cancel the inspection mode. Do not drive the car in this condition.

I checked the engine ECU DTC list, and a DTC will not be logged unless there is a short in the wiring or really bad overheating occurs: 140 degrees C (or 284 degrees F). I don't think that it will be good to wait until that happens before your dealer takes action.

 

probably a big nice person air volume in the cooling system... admittedly it's not easy to get that bled out properly but it's certainly not something you have to live with as "normal". we've put all kinds of demands on our car from nc to key west and all over this hot climate and never once has that thing overheated.

 

when i filled up my coolant after repairing the 2005 prius from crashed condition, it had a lot of air inside, so i had to add more while running heater on max, not to mention if there is nothing in the thermos it would have more air in the system, if dealer wont do anything i suggest u go out one morning after like 12 hours of not driving and open the radiator cap and fill it with s-LLC stuff

 

Just to add to the "crock of sh!t" database:

Last summer I drove from Sacramento (250ft above sea level) to Echo Summit (7200 ft above sea level). There is a 4000 ft elevation gain in the last 20 miles and the outside temp was about 90°F at Echo Summit (it was hot).

If my car didn't overheat on that climb, then it isn't "normal" for the Prius to overheat. And it didn't.

 

Sound like air in the cooling system. The Haynes manual says that you have to bleed it by letting it heat up, then cool, add more coolant and then you should be okay to drive. Many cars are difficult to devoid of air in the cooling system.

It also could be a disconnected cooling fan, too. But I bet that it is air.

 

2G is especially difficult to bleed because of the coolant heat recovery pump that only runs when the car is turned off and when certain logical tests regarding engine coolant temp vs. canister coolant temp have been satisfied. The Toyota repair manual suggests filling the radiator, opening the radiator cap and the bleed port and adding fluid until it appears at the port. Then it requires use of the THHT (hand held tester) to exercise the pump 30 seconds at a time. Then open the radiator cap and the bleed plug, add coolant to the radiator until fluid appears at the bleed port, install the radiator cap. Repeat the process running the CHR pump 30 seconds and adding fluid as needed.

When I log sufficient mileage on my 2004 to replace the coolant, my plan is to hook up a 12VDC power supply to the pump and run it for the 30 second period, in lieu of using THHT.

 

I was thinking this might be possible. Have others done this already? Hopefully there will be a write up on this by the time I need to replace the coolant.

 

It seems pretty clear that it is a problem with improper replacement of the radiator. Since the Prius is notorious for air bleeding problems, that is most likely the problem. The body shop is probably not equiped to properly bleed the radiator. Longo has the rep as the No. 1 Toyota dealer service department in the country. Just go talk to them about your problem. Forget about the body shop.

 

I'm wondering if a vacuum bleeder would work? I have a Mityvac at my hobby farm that hooks up to shop air. A venturi creates the vacuum, so any air in the system should collapse

http://mityvac.com/info_sheets/MV4535_Info.pdf

I've used this kit to flush/refill the 1984 Ford work truck and 1995 Case tractor at my hobby farm. When I'm done, there is NO air in the system

I'm going to guess the 3-way valve in the Prius coolant/thermos system is an additional layer of complexity. However, with a vacuum bleed/refill, I really can't see how a Toyota shop can bugger up a repair like this.

Unless they simply do not give a s*** and want you to ruin your motor

 

From reading the procedure in the service manual, it seems like a lot of patience is required to do this properly, even when using the scan tool to operate the electric pump when needed. Maybe they just don't want to spend the time to do it correctly.

 

Hi Jason,

My 2004 currently has 50K miles. I will probably change the SLLC engine and inverter coolant at 60K miles, so if no one else documents a DIY procedure first, I will do so. Fortunately the repair manual shows a drawing of the coolant heat recovery pump terminals and the correct polarity to be applied so that I don't have to worry about running the pump in reverse.

 

Yes, I am thinking about changing at 60K as well.

Besides the coolant heat recovery tank, you would also need to activate the electric pump for the engine coolant (circulates to the heater core when the engine is off) and the electric pump for the inverter coolant, no?

 

Interesting, on page 126 of the '05 manual it does say:

However, I don't believe they are trying to say this is normal. Those are just circumstances under which the problem is more likely to occur. On the same page the manual also says:

Lastly, on page 246 is the "What to do if your vehicle overheats" section.

Since they want you to follow this procedure every time the light comes on, I would not expect that to be considered normal behavior under any circumstances. I would definitely get the regular Toyota service folks involved, it sounds like the body shop is either clueless, and/or trying to blow you off.

Rob

 

Hi Jason,

Well, the inverter coolant pump will run whenever the car is IG-ON or READY, so no special measures need be taken to force the pump to run. You just have to worry about getting all the air out of the inverter/transaxle cooling system.

Regarding the heater core electric pump, I would run the cabin heater at max temp while the engine is in inspection mode, so that most of the heater core plumbing will fill up with coolant. Then I would put the Prius back in normal mode so that the engine turns off, while keeping the heater running. Hopefully that would encourage the heater core electric pump to run and purge out air in that part of the plumbing.

 

we're going to change out both coolant loops and transaxle fluid once we get back from our trip in a month or so. i can take pics as he does the stuff.

 

That would be very cool, no pun intended. :car: