Overheating?

The amber snowflake light is there to warn you that outside air temp is <=37 degrees F, and that the pavement may be icy as a result.

If you saw the high coolant temp symbol on the MFD, that should not be ignored. Have you had the inverter coolant pump replaced, under the limited service campaign that is currently underway? Failure of the inverter coolant pump is the most likely reason for you to see that warning.

 

Definitely check that inverter pump -- you can tell if it is working correctly when the car is in Ready and you can see turbulence in the IC pump reservoir. On the other hand, once set, a temperature warning for the IC pump usually does not go away on its own.

You may have a problem with your engine cooling system. Check your coolant reservoir. If empty, consider that it had to leave the cooling loop somehow, most likely via the water pump seal. If it is the water pump, your dealer will be extremely happy to replace it for you when you go in for the IC pump recall, since they frequently suggest that repair anyway whether or not the car needs it.

 

Are issues with overheating and heat transfer common with the Gen II Prius? I tow a 1500 lb trailer each weekend in the winter, and haven't had any issues. Should I look into beefing up the cooling system?

 

As I am sure you are aware, that is 1500 pounds more than Toyota recommends. I would consider getting a ScanGauge II or a similar meter so you can know your coolant temps, not guess about them.

 

1500 pounds is only 1500 pounds over what Toyota recommends.

Tom

 

Have you made any suspension modifications to handle the tongue weight? I put rubber donuts in the rear springs to maintain ground clearance in light of extra weight as a short term solution but still have not found a practical long term solution.

Also, do you notice a wider range in your main battery level when you are towing, such as dropping down to 1 bar or going up to 8 bars? I would suggest using B for engine braking if you are at 6 or more bars.

+1 on the ScanGauge idea for monitoring coolant temps, especially if you do any towing in the summer. It would also be good to keep an eye on the main battery temperature -- cycling under heat is the most damaging to them.

Modifying the engine cooling system would be complicated. But the engine is a very robust/reliable component, so that would be the least worrisome. The inverter cooling system also cools the transaxle. That loop would be easier to modify, if you can figure out how to mount another cooler and have an AirLift for bleeding. The transaxle is a little more fragile -- how often do you change your ATF?

 

The snow flake symbol must be a Gen II feature. I don't believe I have that in my Gen III.

 

I think it may even be only a 2004/2005 year model feature and they removed it on later Gen2's. I've got it on my 2005 model.

Apparently it's just a nuisance for people in colder climates where that "warning" light is basically a permanent fixture for about 6 months at a time. For me however it's actually useful because freezing conditions are quite infrequent here. To be warned of the possibility of ice is not such a bad thing for me. Interestingly, in the 20 months that I've owned the car I've only seen the snowflake on about two or three occasion.

 

u need additional cooling if you're going to be pulling a trailer that often.

i've done this.. you're probably burning oil in the process too. if you watch clostly you'll probably see your inverter fluid level slightly drop too. ( i saw a difference only after towing )

don't tell toyota you tow... ever... check to see if you qualify for the inverter pump recall.

i would add cooling systems to your oil, PSD fluid and inverter fluid.. but it should probably be custom.. and on some sort of a switch so you can open or close the loops. you don't want additional cooling while not towing or else mpg drops will be expected...

 

btw.. that light is there as a travelers warning. it to tell you that it's 37 degrees outside, and at that temperature, overpasses (windchill) and shady roads can start to freeze.. and black ice can be kept frozen.

 

Good thing. It shows that the pump is running as it should. No turbulence = no pump = impending inverter overheating = bad thing.

 

It shows that the pump is working - a good thing.

JeffD

 

I just traded my 2010 Gen II Insight for my 2010 Prius. My Insight had a similar light on the dash. Honda said that it was to remind the person that when the light is on not to push the engine too hard until the light goes off. I know it is a simplistic explanation. LOL. I can see the logic in the light, but when I see a warning light come on I assume there is something wrong, not to remind me not to do something.