Grill Blocking Caution

Fro grins, I took my scan gauge and installed it into my '99 Subaru outback today. Water temp rose to 195f. It was just at the midway point on the dashboard temp gauge. If the gauge is close to linear, then 200-210F shouldn't be any real problem to run routinely.

This doesn't address the inverter/mg temps. (I wrote a note to linear logic the other day asking if future software updates would include these temps. the quick response was " we are looking for those codes and are working on it")

Icarus

 

Like so many of you guys I to have my grill blocked 100% most times and if I do unblock it I take the two uppers out. The temps here in SC are around 20's in the morning to mid 40's during the day.

I have ordered a scanguage and can't wait to get it, but my question is what temps should I be worried about and what is the best temps to run it at to get the most out of it.

I have read this entire thread but still I am not sure.

I included a pic of my prius and how its blocked at the bottom. Is this an effective way?

Thanks guys.

Heres my configuration

 

As I just posted in the "First morning with a Blocked Grill" thread, I just blocked my grills today. Reading this thread, I am struck with the gist that above 40-50 Fahrenheit, it is a good idea to unblock some part of the grills. Is there a difference between unblocking the driver's side top grill and bottom grill? Right now, the top slat of the top grill is in 2 halves, so it would be a 5 second job to remove the top most driver's side blocking foam. Should this be enough until roughly 60 degrees OAT? Alternatively, it rarely gets above 90 F here, so is there any reason not to leave the top blocked, and simply unblock the bottom?

Oh, and put my name down as someone who would be delighted to plunk down some (reasonable amount of) cash for an automated remote controlled blocking slat system designed just for the Prius...

 

in summer, i dont block anything... in winter, until it hits a regular 60ºF... i dont unblock anything. its well known that the water temps are remaining within acceptable limits... the only question is the inverters and how hot they can get... unfortunately, no one really has an answer to that. AND unless you have CANVIEW, you cannot monitor the temps...

 

Dont get it!

wy wurry about overheating the prius?
the car sensors will tell you when its time to stop and before there is any damage! thats wat there for!

 

I wish Toyota would offer a "winter" accessory package that links the computers to an insulated shutter system in front of the radiator and an engine block heater. It should be something the car does automatically, not something the driver needs to guess about. It can't take much to raise and lower a shutter system the exact amount needed to keep the temps at optimal levels.

 

Another data point. Today got to about 7 C (45 F) and I had changed my blocking to 100% from it's previous incarnation (halved foam tubes pressure mounted into each and every opening). Taking a mountain highway up, water temp got to 96 C (205 F). I took out the bottom-most foam, and water temp never went above 90C (194 F) (though I didn't put it through quite the same paces).

 

Maybe this is unrelated, but if blocking the grill raises operating temperature (say, the average), you are risking pre-matured failure of cooling system (radiator, reservoir, fan belt, hoses, water pump, etc). Most cooling system components are made of plastics. A 10F rise in operating temperature could cause those plastic parts to crack and snap earlier than they were designed to.

Case in point, BMW V8 engine (BMW 540, 740, etc.)
Ask any BMW mechanics, they will tell you that cooling systems on BMW V8 fail at around 60K miles. (mine at 55K) A survey of owners done in a BMW forum confirmed it. Why?
BMW V8 engines (1997) didn't pass US stringent emission standard on NO emission. So the BMW engineers came up with a solution(more like a hack to me) to raise the operating temperature by 10F (i.e. open thermostat at high temp). That solved the problem. However, owners have been seeing pre-matured cooling system failure ever since. It is a time-bomb that goes off every 60K! I just had a smog check, and here is the value
MAX: 500+ (MAX allowed)
AVG: 50 (average of all vehicles passed)
TEST: 327 (mine, so close to MAX, so far from AVG)

I know this may not be a popular opinion since you guys are so much into grill blocking.
Please don't over-look the 10F increase, which could trigger early failure of plastic parts under the hood. (belt, hoses, tank, etc.)

Also, it would be better to remove grill blocking before you bring your Prius into Toyota dealers for service. Otherwise, they will make a note into their computers and your Prius will not be covered for related failure in the future.

 

I suspect Dave B. is a fan of Hitchhiker's Guide in which "don't panic" is a guiding principle, so no one should be offended. I'm a new owner ('08, silver, package #4) and today I bought some foam for the upper grille and half the lower. We've owned a Lexus RX400h for 2 years and this forum is a revelation. I'm on my way to the site store for a ScanGuage II, which looks easy to install on the dash. Thanks to all for their feedback, and especially to Dr. Fusco, who clearly spends too much time at his computer.

 

I agree, I think the good doctor is fast becoming a doctor of Priiology....

 

Hey, Troll Slayer!

A couple of weeks ago I too blocked all my front grill slots for the winter and used my ScanGuage to monitor coolant temperature. I took a 70 mile highway trip during one of the recent unseasonably warm days and stopped to remove a strip as the temperature climbed near 200; the temp immediately fell into the normal range.

However, this morning I took my 2007 Prius in for replacement of the water pump -- not unusual apparently at or slightly more than 30,000 miles. The tech noticed the grill blocks and recommended removing them -- primarily because of the inverter's need for coolant. Don't know if this is BS or not, so, 1) what do you think of his opinion, 2) what is the normal operating temperature range for the inverter, and 3) is there a gauge that monitors the inverter's temperature?

Thanks so much.

 

before we start; 200º F is well within normal operating temps. water boils at 212. that you want to stay away from although anti-freeze and pressure helps with that as well

1) if you are seeing temps above say 60 on a gen 2. remove part of the LOWER grill, on a gen 3 parts of the UPPER grill. that is where the converter is

2) when you find out, let me know

3) if there was one, answer to #2 would be easy...but its not

FYI; its normal to see temps hitting up to 206 or so. i see it all the time during summer with zero grill blocking. common if its warm out and AC is running.

 

Normal temp of the Inverter coolant on my 2010 is 20 degrees over ambient, and for any electronics the cooler the better.

 

Hi All,

The transmission is cooled by air-flow in a Prius, and I believe the inverter radiator is over their too on the Gen II. On my Gen II as weather got colder, the left side was blocked more and more. Even at 5 degree F weather, I still had one slat to the left of the license plate (relocated down across the grill) open. For 50 F weather I had the full left side open, and one of the 3 (4?) slats on the lower grill on the right open. I blocked my upper grill year round. I did not start blocking left of the license plate till morning and night below 32 F.

I am not sure how running in the 190 to 210 range is going to damage the water pump. At that temp, the thermostat is wide open, and forces on the impeller will be the smallest, right ?

My driving was not very power demainding in my Gen II. I pulled some 70 mpg tanks with it during the summer, and was usually above 60 mpg until freezing weather set in.

 

how do you measure the temp?

 

They use a ScanGuage. H

 

Scan gauge 2 , I watch the engine temp, inverter temp, RPM's and HP , works good. Ted

 

I thought the Inverter cooling loop was at the bottom of the radiator, whereas the engine is the top part:



Seems like you'd want to block the top and keep at least some of the bottom open to give the inverter loop some air?