Transaxle replacement thread: Orange4boy's 2003 Prius

I found that running the car completely out of gas (carry a 1 gallon spare in the trunk) seems to reseat the bladder and calibrate the fuel indicator. I can not explain it but that was my impression. When the engine runs out, just use the traction battery to get to a safe place to refuel from the 1 gallon spare.

Bob Wilson

 

Hi orange4boy,

I have a question for you regarding your post ages ago regarding installing the circulating engine block heater in your prius. I make quite a few short trips in my 2008 and it's really depressing the fuel economy. after three years are you happy with the installation? do you have any tips about how you installed it? degree of difficulty, etc?
Sorry to impose on your time and good nature, but i believe a tank style circulating heater would do render the best result.

Regards,

Martin (Cloverdale)

 

Hi Martin,

Orange4boy also hangs in "Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com" but I haven't seen much recently. I would recommend using "Conversation" as this will send a note via his last e-mail. But I have some thoughts to share about the coolant heater.

The standard block heater for the 1.5L engine is located in a difficult place to reach behind the engine block and firewall. It works on the principle of 'heating the block.' I have found it adequate if you are heating the car and disconnect just before leaving . . . 30 minutes minimum, 1 hour max based upon local electrical rates.

I bought and recently threw out a circulating heater. It was expensive and required modifications to the engine coolant hose lines. I've seen too many cases where aftermarket systems can weaken the hoses and lead to 'steam escaping'. Murphy's Law says it will always happen at the worst time. I don't think they are that reliable.

In North America, you should have a functioning, coolant thermos and pump built into the car. Have you seen some problem where the engine coolant does not show an immediate increase on the first trip of the day?

I have no expertise in how the coolant thermos works but I suspect there is some software controlling when the coolant in the thermos is replaced. I would recommend checking the Gen II technical forums to see if there is a credible description of how that works.

One last thought, the transaxle oil temperature also has a measurable effect on mileage. Our Gen I takes at least 20 minutes to reach operating temperature. I have tried two, contact heaters and both have 'broken the wires' at the heating element that is attached to the transaxle oil pan. But before they broke, I could see they were excellent compliments to the engine block heater when temperatures were 40F (5C) or lower. You may want to look there too.

GOOD LUCK!
Bob Wilson