Update to Grill Blocking Please

morpheusx · 09-14-2007, 08:03 AM

Here in Ohio the temps are now dipping into the 40's and peaking in the mid 70's meaning that Fall is right around the corner. I am planning on doing some grill blocking for the fall, winter, and spring. I've done some searches and I seem to see lots of conflicting information. Some have said its best to just block the upper grill until it really gets cold and I've seen threads that say to block the lower part first.

My main questions
1) when temps range from the 40's to 70's what part should be blocked (it seems I have also read some saying they leave their upper blocked all year round even in the 90's in the summer.)
2) what temps should I wait for full blockage.
3) How beneficial would it be to leave approx. 50% lower and 50 % upper blocked.

FireEngineer · 09-14-2007, 09:32 AM

Our temps in Chicago are about 55F morning and peak at 75F. Blocking the upper fully is no problem. The lower you can block fully in the 40's, remove one or two slots of block when you go home. Right now I'm running upper full block and lower 3 out of 5 slots blocked, ScanGage shows I'm gaining about 10-12F in the morning commute, up to 15F afternoon.

Unless the outside temp is 50F or less do not block the lower fully unless you have an instrument to monitor engine/MG temps.

If you have an engine block heater, blocking will help retain the heat. At 55F in the morning without the block the EBH will get up to 125-130F, with the block the temps gain 5-10F.

Wayne

Allannde · 09-14-2007, 10:03 AM

I do have a Can-View and I do monitor engine temperature. I also block the radiator.

I unblocked the upper grill last spring. I finally unblocked the lower grill in July when it got really hot here in Washington State.

I have never seen engine temperatures above 200 degrees except crossing mountain passes. Then it was never above 209 degrees and only for a few minutes. Please note that with a pressurized system, 230 degrees is safe.

I also monitor the MG1 temperature and have never seen it over 150 degrees.

Having said that, I totally agree with FireEngineer's advice that one should not block the grill above 50 degrees unless you are monitoring the engine temperature. There is just too much to be lost by overheating if that occurs.

Prius 07 · 09-14-2007, 10:07 AM

<div class='quotetop'>QUOTE(FireEngineer @ Sep 14 2007, 09:32 AM) [snapback]512456[/snapback]</div>

Quote:

Our temps in Chicago are about 55F morning and peak at 75F. Blocking the upper fully is no problem. The lower you can block fully in the 40's, remove one or two slots of block when you go home. Right now I'm running upper full block and lower 3 out of 5 slots blocked, ScanGage shows I'm gaining about 10-12F in the morning commute, up to 15F afternoon.

Unless the outside temp is 50F or less do not block the lower fully unless you have an instrument to monitor engine/MG temps.

If you have an engine block heater, blocking will help retain the heat. At 55F in the morning without the block the EBH will get up to 125-130F, with the block the temps gain 5-10F.

Wayne
[/b]

I understand this works well for short commutes. Are there any issues / risk with taking a long drive with blocked grills? Would the temperatures get to hot / need to be monitored? I do not currently have ScanGauge.

Thanks,
Gabe

FireEngineer · 09-14-2007, 01:09 PM

<div class='quotetop'>QUOTE(Allannde @ Sep 14 2007, 09:03 AM) [snapback]512471[/snapback]</div>

Quote:

I unblocked the upper grill last spring. I finally unblocked the lower grill in July when it got really hot here in Washington State.
[/b]

You might want to try to unblock the lower grill first since the inverter coolant is the lower 1/3 of the radiator. Engine runs real cool, inverter can get hotter faster.

<div class='quotetop'>QUOTE(Prius 07 @ Sep 14 2007, 09:07 AM) [snapback]512475[/snapback]</div>

Quote:

I understand this works well for short commutes. Are there any issues / risk with taking a long drive with blocked grills? Would the temperatures get to hot / need to be monitored? I do not currently have ScanGauge.

Thanks,
Gabe
[/b]

When I went on my western EBH road trip I had the block I described earlier all the way to Amarillo, TX. Temp outside was about 100F, had the AC on 75F medium fan when I decided to take out all the block since I knew I would be encountering higher elevations/mountains/climbing later in the evening and I can't monitor the inverter/MG's with the ScanGauge. But all through IL, MO, OK and TX-temps 80-95F-rolling terrain in MO-engine never went above 197F. Upper should be very safe, lower on flat terrain should be OK if outside is under 60F. Remember, these grill blocks are not air tight, some air gets through, especially on the highway.

Wayne

Prius 07 · 09-14-2007, 01:35 PM

<div class='quotetop'>QUOTE(FireEngineer @ Sep 14 2007, 01:09 PM) [snapback]512581[/snapback]</div>

Quote:

When I went on my western EBH road trip I had the block I described earlier all the way to Amarillo, TX. Temp outside was about 100F, had the AC on 75F medium fan when I decided to take out all the block since I knew I would be encountering higher elevations/mountains/climbing later in the evening and I can't monitor the inverter/MG's with the ScanGauge. But all through IL, MO, OK and TX-temps 80-95F-rolling terrain in MO-engine never went above 197F. Upper should be very safe, lower on flat terrain should be OK if outside is under 60F. Remember, these grill blocks are not air tight, some air gets through, especially on the highway.

Wayne
[/b]

Thank you Wayne! This morning the temp here was 57F but now at noon it shows 82F (really???) The last two cool mornings my MPG was much worse for my short commute to work and made me think about blocking the grill at least partially.

Gabe

Neicy · 09-14-2007, 02:10 PM

Think it's about time to do in New England too. Was 61 this AM.

hobbit · 09-14-2007, 05:10 PM

The lower grill opening is where the vast majority of the air comes
in. The piece of coroplast is still in my upper one since I
put it in and is probably going to stay indefinitely; people often
ask about the "yellow smiley" and it's a good explanation-conversation
starter. The lower one leaves a little open space at the ends, and
I'm thinking maybe I should do the full wazoo for this winter.
Taking the nose off the car would probably make it easier and give
another opportunity for some disassembly pix, not to mention a bit
o' cleanout...
.
_H*

JimN · 09-14-2007, 09:09 PM

My upper grill stays blocked. No problems cross country to Indiana in the 90's. The lower grill will get blocked when it stays "cold".

morpheusx · 09-14-2007, 10:57 PM

Thanks I decided to do full upper and plan to make that pretty much permanent. As far as lower I just slid in a 3foot tube over the lower 2 slots and will just leave in place unless we have another hot spell, I am going to wait to block the other 3 slots on the bottom for when the temps stay below 45.

09-14-2007, 08:03 AM	#1
morpheusx Professor Chaos Join Date: Mar 2007 Location: Akron, OH Posts: 1,506 My Car: 2007 Prius Model: Package: #2 Thanks: 7 Thanked 39 Times in 25 Posts Friends: 3	Here in Ohio the temps are now dipping into the 40's and peaking in the mid 70's meaning that Fall is right around the corner. I am planning on doing some grill blocking for the fall, winter, and spring. I've done some searches and I seem to see lots of conflicting information. Some have said its best to just block the upper grill until it really gets cold and I've seen threads that say to block the lower part first. My main questions 1) when temps range from the 40's to 70's what part should be blocked (it seems I have also read some saying they leave their upper blocked all year round even in the 90's in the summer.) 2) what temps should I wait for full blockage. 3) How beneficial would it be to leave approx. 50% lower and 50 % upper blocked. __________________ Current LIFETIME is 54.2 MPG

09-14-2007, 09:32 AM	#2
FireEngineer Senior Member Join Date: Oct 2004 Location: SW-Side of Chicago, IL Posts: 1,156 My Car: 2010 Prius Model: IV Package: Solar Roof Thanks: 1 Thanked 51 Times in 39 Posts Friends: 12	Our temps in Chicago are about 55F morning and peak at 75F. Blocking the upper fully is no problem. The lower you can block fully in the 40's, remove one or two slots of block when you go home. Right now I'm running upper full block and lower 3 out of 5 slots blocked, ScanGage shows I'm gaining about 10-12F in the morning commute, up to 15F afternoon. Unless the outside temp is 50F or less do not block the lower fully unless you have an instrument to monitor engine/MG temps. If you have an engine block heater, blocking will help retain the heat. At 55F in the morning without the block the EBH will get up to 125-130F, with the block the temps gain 5-10F. Wayne __________________ 2010 Blue Ribbon Metallic Prius IV w/Sunroof-Solar-Navigation 2005 Salsa Red Package 6 (BC)-Retired 6/12/2009 w/89,989 miles Average MPG 54.5, Best tank MPG 80.1/932 miles 2004 Oldsmobile Silhouette "Final 500" mini-van Free engine block heater install, just ask. 165 warmer Prius done to date. Including one very special 2010 Prius. Come join us at the ChicagoPriusGroup.

09-14-2007, 10:03 AM	#3
Allannde Senior Member Join Date: Jan 2006 Location: Washington State Posts: 437 My Car: 2006 Prius Model: Package: #8 Thanks: 0 Thanked 1 Time in 1 Post Friends: 0	I do have a Can-View and I do monitor engine temperature. I also block the radiator. I unblocked the upper grill last spring. I finally unblocked the lower grill in July when it got really hot here in Washington State. I have never seen engine temperatures above 200 degrees except crossing mountain passes. Then it was never above 209 degrees and only for a few minutes. Please note that with a pressurized system, 230 degrees is safe. I also monitor the MG1 temperature and have never seen it over 150 degrees. Having said that, I totally agree with FireEngineer's advice that one should not block the grill above 50 degrees unless you are monitoring the engine temperature. There is just too much to be lost by overheating if that occurs. __________________ White 2006 Package 8, clear bra, block heater, ScanGuage, Highlander side mouldings

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09-14-2007, 02:10 PM	#7
Neicy Senior Member Join Date: Apr 2007 Location: Wakefield, MA. Posts: 804 My Car: 2009 Prius Model: Package: #2 Thanks: 5 Thanked 0 Times in 0 Posts Friends: 6	Think it's about time to do in New England too. Was 61 this AM.

09-14-2007, 05:10 PM	#8
hobbit Senior Member Join Date: Mar 2005 Location: Bahstahn Posts: 3,630 My Car: Model: Package: Thanks: 0 Thanked 216 Times in 118 Posts Friends: 0	The lower grill opening is where the vast majority of the air comes in. The piece of coroplast is still in my upper one since I put it in and is probably going to stay indefinitely; people often ask about the "yellow smiley" and it's a good explanation-conversation starter. The lower one leaves a little open space at the ends, and I'm thinking maybe I should do the full wazoo for this winter. Taking the nose off the car would probably make it easier and give another opportunity for some disassembly pix, not to mention a bit o' cleanout... . _H*

09-14-2007, 09:09 PM	#9
JimN P719 of ??? Join Date: Nov 2006 Location: South Jersey Posts: 2,702 My Car: 2006 Prius Model: N/A Package: #3 Thanks: 0 Thanked 30 Times in 28 Posts Friends: 2	My upper grill stays blocked. No problems cross country to Indiana in the 90's. The lower grill will get blocked when it stays "cold".

09-14-2007, 10:57 PM	#10
morpheusx Professor Chaos Join Date: Mar 2007 Location: Akron, OH Posts: 1,506 My Car: 2007 Prius Model: Package: #2 Thanks: 7 Thanked 39 Times in 25 Posts Friends: 3	Thanks I decided to do full upper and plan to make that pretty much permanent. As far as lower I just slid in a 3foot tube over the lower 2 slots and will just leave in place unless we have another hot spell, I am going to wait to block the other 3 slots on the bottom for when the temps stay below 45.