Engine runs most of the time 2012 PiP

While I absolutely agree with that, a sudden and continued LARGE change in the operation of the engine should be questioned.

And if they REALLY were watching all of the significant parameters while the unusual engine operation was noted, they should be able to pinpoint WHY it was doing that.......and prove pretty much beyond a shadow of a doubt whether the condition the engine THOUGHT it say really was there or not.

I think having it documented on two service visits should be plenty to make your case for service after the warranty........should it continue with this strange behavior after the weather warms up.

The did at least check the engine oil and coolant levels.....right ??

My C exhibits similar behavior when it is "cold" (which here in Florida is 40F) but it only lasts for maybe 10 minutes or 5 miles and after that goes back to "normal". I can see how the behavior could continue intermittantly for a long time IF the temperature was extremely low.......like 0 degrees F......or if the sensors THINK the temp is that low. Or it thinks that the coolant never gets hot, just for instance.

 

Better yet, just turn off climate control. Use the seat heaters if needed. This is only to rule out what is normal operation.

But this sure sounds like it's merely the climate control trying to warm the engine enough to provide cabin heat.

And if you were the one asking the question, you'd have a point. You might review the CONTEXT of this question - it's about the engine coming on seemingly at an inappropriate moment.

 

Well, it's not all parliamentary procedure in here, some of us just say what's on our minds. When someone suggested turning off the heater to save fuel, I had to comment. BTW, what little fuel you may save by not using the heater, the power-consumption of the electric seat heaters is sure to exceed it.

 

But the poster wanted to know why the engine was coming on. It is pretty much for sure that it is coming on BECAUSE he has asked for the heater to be on. Whether someone wants to drive in cold weather with or without the heater on (or seat heaters on or off) is their own choice. I think that Brad can tell us now if in fact the engine comes on with the heater turned OFF...that would probably indicate a problem.

Mike

 

Point of order. Got it.

 

Cogeneration is only possible with the gas engine. It is done to boost the overall efficiency of PHEV. For BEV, it has no choice but to use the battery.

 

In the purest sense of the term, you are correct. Harvesting the waste heat from a combustion engine to use for heating is what most automotive interior heaters do. But this discussion brings up a good point; how much fuel is wasted by requiring the engine to stay warm for purposes of heating the interior? My guess is that it isn't a lot in comparison to the energy that would be lost if electric heating elements were used, despite the fact that virtually all electrical heating is nearly 100% efficient. Perhaps the only way to improve on this would be to return to the gasoline-powered heaters of Volkswagen fame.

 

My C does that ALL the time. It is designed to warm up the engine whether it really needs to or not.
That happens even when the outside temp is 100F and the garage is at maybe 90.

NOW.......it normally does NOT race when it is doing that and it still stops when the car is not moving......except maybe at the first stop........except when it is cold out and then it sounds differently and runs longer.

No offense intended here but it is possible that your PERCEPTION of what is happening in cold weather has just changed.
That is, it was doing this last winter too and you just did not notice it.

 

I haven't been crawling around under a Prius, but perhaps the coolant could be pre-heated by attaching a magnetic oil-pan heater to a coolant line, so that the coolant is warmer when you start the car.

 

I think those things are pretty slick.
The problem is finding something that they will stick to, magnetically.
The heat won't transfer very good on something like a "line" but the oil pan, block or radiator would be good choices.
Alas, on many engines, those parts are NOT magnetic.

 

Attaching it to the oil-pan itself might accomplish everything is left plugged-in long enough.

My preference would be a 1500W circulating heater, controlled by a coolant-temperature thermostat, and timed to come on at an appropriate time.

 

this is not true for the pip, it does not start the engine if it has a wall charge, unless the temp is set above 'low', or the front defroster is 'on' or the temp is below 14 degrees f. see the sticky faq for all the possible situations a pip may fire the engine, mine almost never comes on in winter, unless i want heat. the o/m also lists the possibilities. (sorry for the post brad, i couldn't help myself)

 

That's it right there. Turn off your HVAC and the engine will not fire up. Its not a winter thing. Its disappointing the dealer didn't diagnose this for you. It's also interesting you didn't notice this problem since new. Perhaps your heated garage used to keep the interior warm enough?

The PiP does not have an electric heater. If you ask for heat above ambient, it has to fire up the engine to provide that heat.

 

You may want to crawl around the Prius Chat store - and in stead, recommend a Toyota OEM item ... the block heater - rather than bork things up using aftermarket stuff;



Those of us who regularly can get 70mpg - even in the Gen II, wouldn't leave home w/out it. Even helps during cool summer mornings.

.

 

I have a block-heater, as nearly all Canadians do, but I was considering something that isn't designed to be left plugged in for long periods of time -very wasteful. My idea was to quickly get the system up to operating temp to eliminate warm-up, and minimize all the heat losses that occur with a block-heater.

 

all the best.

 

Actually, it's not setting the temp above "Low." It's whether ambient temperature is below the temperature set. Example for me, I set it for 68 during the cool season (such as it is in SoCa). My PiP is in the garage, but the temps in the garage got below 60 a few days. On those days, sure enough, the engine fired up a few seconds after powering up. And simply turning off the climate control system eliminated it.

It will be interesting to find out what the OP's dealer finds.