2010 Prius Grill Blocking strategy

I have a 100% lower grill block and fully open uper grill. Just got a ScanGaugeE and started to monitor the water temp this week.

It seems that it is kind of hovering around 190F ... (185-195) yesterday was a very very warm day in New York and drove it in the city traffic jam and did not see anything over 193 ...

My question is it a safe range or not ... again I had no chance to see the temp before this week. Should I leave the blocking for the summer or not???

Engine turn off at around 115-120 (constantly every morning). Which happens about 3 blocks from my house from a "cold" start.

 

I plan on leaving it in. Of course we don't see temps above 75 usually. I believe 208 is max but Ken@Japan had a real nice write up on this subject in the past.

 

Just adding ... anyone knows when the electric fan starts cooling ?? I guess that would be the max I would want to go ..

I tried to check ... scangauge was showing 193 when I stopped and got out ... tried to listen but was no obvious fan noise ...

Not sure what 208 max means in the response above ... it shouldn't go above that or that's when fan starts or thats when the thermostat opens and start the pump ??

Thanks.

 

Good question... from previous discussions I believe that was the upper end of the "normal" operating range and anything above that was overheating. I thought that was discussed in this thread but I search and couldn't find any reference. Will look around so take that number with a grain of salt... as should most things on internet.

 

Sorry if this has been covered but: any ideas how grill block impacts air conditioning efficiency?

 

Thanks...

If that is (someone can confirm?) what 208 is. so far I am good. It really seems to me that "something is happening" around the 190 range... even in heavier loads I can see temp raising a little bit above that like to 196 but then it starts dipping slowly back .... so far I have not seen anything over 200

I am driving basically the same way ....

The real advantage of the scangauge tool is that I can see the max of the trip/day/yesterday etc. so I can surely say what was the max water temp even if I missed it while driving.

Cheers

 

I read in john1701a's guide that the fan will come on around 195.

I have driven up a very steep, mountain road with the lower grill block and the max I saw was 203. With that said, it smelled very hot when I got to the top. Temps were in the 20-30s.

 

it doesnt. the A/C is 100% electric and has NOTHING to do with engine temps since it does not run directly off the engine

as far as what is safe, i think what you want to do is stay below the point in which active cooling kicks in. now water NOT under pressure boils at 212. so 208 UNDER pressure is well within the safe range.

 

Not sure but I think what she/he means that blocking the grill may or may not affect the a/c since whatever it is it MUST be cooled. Just like at home of course it is electric but, how/where it is cooled ??? and of course the A/C efficiency does depend on the heat exchangers on both side she/he is asking on the "hot" side ... I have no idea where the A/C heat exchanger is but it must be in the engine compartment so if that is "hotter" because of grill blocking A/C efficiency WILL suffer.

My 2cents

Gabor

 

The principal of an air conditioner is to take a cool, low pressure liquid of some sort (used to be Freon), place it in proximity with air mass you want to cool, so that it absorbs some of that heat in the air. Then pressurize it, compressing it and concentrating that heat, and run it through a radiator: typically a secondary radiator at the front grill. I'm just looking for pics, not sure, but think the main front radiator grill on the prius is the A/C cooling radiator:



It's a "he" btw. I know, it is an unusual name

 

Thanks for the pic.

As I said blocking the grill COULD unquestionable affect A/C efficiency ... you are on the right track the heat from inside must be "disposed" somewhere outside ... and if it is "harder" because of the grill blocking efficiency suffers.

But I think (not sure) what you point out on this pic is the inverter cooler on the top... that is why upper blocking is not recommended as much ...

Again can someone point out where the A/C cooler is for sure???.... but as I said it is somewhere in the engine compartment and blocking the grill may have an effect.... if that is the A/C cooler blocking upper grill will HAVE negative effect on A/C efficiency.

Again A/C doesn't seem to be a big factor ... recently I had to run some A/C (New York this week was 96+ degree ) I drove the same route as usual and MPG was not affected noticeable (I have a scangauge-e to monitor stuff).

 

It's that big rectangular thing in above pic

 

Drove up the mountain road again yesterday... it was 2.5 miles (pretty much straight up with switch backs) with 100% lower grill block and 55F outside. The temp rose to 197F but that was it. Granted it smelled hot when I got to the top.

 

I do not have the original diagram but the bigger rectangular thing is the engine cooler radiator certainly not the A/C (marked yellow)

The smaller on the top "possibly" the A/C cooler but from other drawings it is indicated that that is the Inverter Cooler radiator not the A/C (circled with red).

 

You might be right, and sorry for the sarcasm. The Repair Manual is the pits: very terse and sketchy.

On previous Honda's we've had, both the coolant radiator and AC radiator are quite big, stacked one behind the other, typically the AC in front.

I haven't had a good look at what going on with our Prius, as yet. I've been meaning to take the plastic trim pieces off that are above it. It should be understandable if you look at what lines run in, and where.

My feeling: as soon as you get into temps needing AC, stop grill blocking completely.

I've gone that route, but I have left in a couple of pieces of the styrofoam pipe insulation along the side edges of the engine bay opening (just under the hood). This traps residual heat when you're parked.

I may take this out once summer finally arrives in our area. We've had a very cool spring.

 

I am not sure what you mean "side of the edges...."

I am going to take a picture what I have now... basically two tubes pipe insulation blocking the lower grill

Now I have a scangauge for over two weeks the highest water temp was 202 .... and we had almost 100 degrees here in new york... so I think I am OK.

I will open the hood and try to trace the line for the upper rectangular cooler....

But I can not believe that any car has a bigger or even as big a cooler for A/C then for the engine...

 

Was going to take some pics, but then realized my better half has it right now. Anyway: regarding the side of engine bay insulation I've put in, at suggestion I read here:

If you pop the hood, and look at the side edges of the engine bay, just at the hood seam, there's a lip of metal there you can push insulation tubes onto. When you drop the hood down it will pinch it slightly, sealing air in the engine bay better.

 

I'll make a believer of you yet



This is from service manual for our previous 2006 Honda Civic Hybrid. Much better book BTW: concise/complete, informative, paper version reasonably priced. That's one thing Honda does right.

 

#10 in the picture if this helps...
2010 TOYOTA PRIUS A/C Evaporator Core

 

That's the Evaporator, the cold bit, that's in the heat/vent unit under the dash, the thing that cools the passenger compartment air, the low pressure side.

The Condenser is out at the front bumper, at the high pressure side, it's the bit that gets rid of the heat. It needs a good sized surface area to accomplish this.

It's kind of analogous to a dish cloth: blot up liquid, then wring it out. Except: sub. heat for liquid.

Same website, it would be item #1 on this page:

http://www.dealerdirectparts.com/2010-TOYOTA-PRIUS-A-C-Condenser-p/toyota-6028308-prius-4.htm

Kind of hard to judge scale, but looks substantial. The empty portion at the top of the two vertical rails is where the inverter radiator bolts in, I think. This thing covers a wide and deep portion of the frontal area of the car. The radiator for engine coolant is likely a similar sized second layer, behind.

Compare also to the pic's up the page from the Toyota Repair Manual: the only diff. is the inverter radiator is bolted in there: the slim bit at the top.

If you take the plastic trim off, above the radiator zone, it should be easy to sort out what it is. It will have the small diameter aluminum tubing running to it.