Engine block heater

<div class='quotetop'>QUOTE(Frank Hudon\";p=\"67328)</div>

Frank:

Boy you won't get any argument from me on *that*

This has been a brutal winter.

 

<div class='quotetop'>QUOTE(tomdeimos\";p=\"67400)</div>

Tom:

That's what is holding me back from trying a winter front. There are a few automotive shops here in Winnipeg that will custom-make a very nice looking winter front. Sure beats a piece of cardboard or carpet stuck to the front of your car.

I'm going to have to ask my Prius tech if there are any unused taps on the motor to hook up a mechanical temperature gauge. I have an Autometer ProComp still in the box with a 6ft capillary. It would be perfect.

I know the vast majority of PriusChat members don't have to worry about temps of -30 C to -40 C, but my biggest complaint to date (My *only* serious complaint) is the heater performance at temps colder than -20 C.

Any ideas? Rick or Kyle??

 

if nothing else pull the block drain and install it there. It's on the back side of the ICE and easily accesable.

 

Frank:

AH, now we're getting somewhere!

 

The carpets I got are stiff enough to so far just sit against the radiator. I
removed the top plastic held by 6 fasteners to install between the grille
and the radiator. So not visible from the front of the car. One side
drops in and the other you have a plastic grill piece that goes right across
in the way but carpet can be squeezed past it. I put the plastic cover
back on, but if I need to make adjustments I may leave it off and
just add or remove the carpet on one side depending on temps.

Really would like a shade or louvers I could open and close as needed
with all the temperature fluctuations we get here. Don't see an easy way
to do that.

And tonight I got an Autoxray hooked up and working a little: Air temp
on the car display was 25 degrees F. Car reported a coolant temp of
170 degrees F after about 10 miles. I continued for about 40 miles and
got the temerature reported up to around 196 max going uphill slightly
at 65 mph. and with the heater turned off. Going down hill or slower it cooled off again to 170 range or lower.

========================
Just checked the manuals and for reference:

Thermostat should be fully closed at 171 degrees F or 77 C
Thermostat should start to open by 176-183 degrees F or 80 to 84 C
Thermostat lift spec'd at 205 F or 95 C which I assume is full open
At 212 F or 100 C the electric fans should be going (even with AC off)

 

Tom:

Thanks great info.

However, I'm *very* reluctant to actually block off the radiator. If you're not paying attention to things, and the motor does get too hot, it's impossible for the cooling fans to work if the rad itself is blocked off.

A rad shutter, like those used on HD trucks, is as you say the ideal solution. They're "fail open" by design so if electric power or air pressure (HD truck) is lost, they immediately open.

I like using a winter front that just blocks off the grille. You still get most of the benefit of blocking the rad, but if you get inattentive the electric cooling fans can still kick in and pull some air through.

Next time in to the dealer, i'll ask about having my Autometer mechanical temp gauge installed. Asides from the Toyota Echo and Echo Hatchback, every other Toyota car sold here has a temp gauge. Even if it's only marked "C," "Normal," and "H" that is still better than nothing.

 

If we just had the mini scanner for the G3 (04-05) Prii. Heavy sigh.

 

I have to agree here. My meausrements show the car gets really warmed
up, and other data I have collected show it running too cold as well. All
depends on the speed and hills. A fixed baffle of any kind won't solve
the basic problem. Part of the price for our efficient engine.

I tried to protect things by leaving the 1/4 of the radiator uncovered, and
this seems to work for my conditions up to 35 degrees F ambient. But above that or If I drove faster, the fans could turn on and that would kind of defeat the purpose.

So my newest numbers are I get the car to 180 degrees and it is all hot,
then get off the highway and drive 30-40 in town. Car cools to like 140
at 30 degrees. So it is easy to see why people get no heat in city
driving at 40 below!

My current plans are to cover only up to maybe 1/2 the radiator to be
safe. And ultimately the louvers that open and close would help if I can
find some that fit.

Just want to warn people not to try this unless you at least can measure
temperatures to see what is happening.

A better approach may be to find ways to insulate the engine better,
divert air under the car leaving the radiator fully functional. Then insulate
the cabin a bit better. Not sure there is room to do this, but I think the
temps could be kept up closer to the proper 170 range much better, and no overheat danger when the loads get heavier.

I found this neat device that only needs 0-10 volts to control it. I think
it may be too big to use on a Prius, but I like the concept.

see:
http://www.continentalfan.com/lit.htm
and click on the Iris Damper

 

Tom:

That's what I noticed too. I would leave the heated underground parking, the heater working fine, and after a couple of blocks at -40, cold air. It appears our Prius has more in common with a diesel motor, at least wrt heater performance in the cold.

I'm going to stop in and check with my Prius tech about a mechanical temp gauge. About the only thing worse than freezing my a** off at temps colder than -20 C would be if I blocked the rad and severely overheated the ICE or inverter.

BTW how are you checking your temps? Something like Auto X-Ray with CANbus adapter?

 

I bought the Autoxray 4000. Doesn't read much of what I want to see, but can't afford
a real Toyata/Vetronics yet.

But it does read both Air intake temp so I can see the extension hose I put on works.
And it reads Engine Coolant temperature.

Also seems to handle the basic OBDII stuff, but can't get the O2 sensor tests to work.
So far it says no error codes, so no idea how well it reports them.

Some other interesting stuff is the throttle position, engine load, and the Readiness
tests (I have a green knob for my 12 volt battery I disconnect it so much!)

NO readout for actual Radiator temperature, but you can tell when it gets up to engine
temp levels because as the engine thermostat opens and closes the temp cycling
decreases, and then you just get to a point it stays open and the readout gets hotter
but without much fluctuation at steady loads.

So you can easily see where you are at compared to where the fans will turn on. And
I would pull stuff out at that point and not wait for alarms to go off from the overheat
warning.

No easy way to build it into the dash, so a guage would be nice, but I think I might want
something better than C to H. Maybe a digital guage with degree read out. I'm getting
used to that now.

 

Well, as far as temp gauges I have an Autometer ProComp mechanical gauge sitting in its box. It has a 6ft capillary. I got the gauge for another project around 5 years ago but never needed it.

I did stop in today to see if my Prius tech could answer my question but he was too busy. Will stop in again to ask.

I suppose if worse came to worse I could get one of those RTD sensor gauges. Take off the rad hose at the thermostat and put the sensor capsule inside, then slip the hose back on.

And although it's cool to play with a software program like Auto X-Ray, I'm not willing to have a Palm sitting on my dash just to know what my coolant temp is.

 

But the Autoxray has a nice RPM readout too!

I agree it is bulky and I consider this temporary. I may try to add guages,
or just not worry once I see what works over my winter temperature
extremes. But here I just have to cover like 0 to 50 degrees, not to -40.

My latest arrangement seems to work best and safest so far: 1 carpet blocking front of radiator on engine side. (so 50% of radiator blocked) Then second carpet scrap on
same side betwen the engine and the radiator. It just sits on the hoses
etc, and is closest to the radiator at the top so any air flow gets diverted
down under the engine. My next step would be to see if I can cover the
oil pan. No room to insulate much else.

Highway I now get peak 186 degrees, at 36 ambient.
City speeds I get cooling to 170 at 30 degrees. Now I have
to wish for a day or two of cold weather!

 

Tom:

Oh, that's easy. Just visit me for a few days. You should have been here in January. Though sorry to say guest parking is an elevated concrete ramp exposed to the elements.

Seriously, it looks like the motor will never get super hot in normal use. Usually you encounter a car or pickup that overheats easily. Such is not the case with the Prius.

 

the best I could get was 93C in the middle of summer with A/C going sitting in traffic. 86-88C in the winter or what passes for winter here on the coast. Oh not to rub it in but the cherries and the ornamental plums are in bloom and I'll have the first pick on the ruhubarb in a week or two.

 

<div class='quotetop'>QUOTE(Frank Hudon\";p=\"68515)</div>

GRRRRRRRRRRR!

 

ooooppppppsss sorry your taking it so seriously!

 

Frank:

Should have had you out here in January at -40. Now *that* is exciting!

Seriously, send me some rhubarb when its ready. Yum!

 

well in a 4 day streach in Jan I dumped just over 5" of rain out of my rain gauge. And don't worry I know what -40 and colder is all about, as I lived for 12 years in Dawson Creek, Mile"0" of the Alaska Hiway. What I do miss about that is when it's really cold it's sunny. Tweek your brain, freeze your butt.

 

Well, if you can do without the cold, so much the better. I'm not sure I like rain though, it's a poor substitute.

I didn't mind the "cold" at all living in Salt Lake City. And having spent some time in places like Mesquite, Nevada and St. George, Utah, I know very well I could *really* settle into a place like that.

My Prius would also get one h*** of a lot better fuel economy in winter, and I wouldn't have to p*** and moan about the poor heater performance. I do know the A/C works great.

 

jayman I just came across this thread. I will give it some thought and let you know. would some like to send me a pm on a thread like this that I haven't posted on when your asking me a question so I don't ignore you on accident.