Grill Blockage + Burning Smell?

Engine probably was fine, my recent mountain driving with a ScanGauge showed max temp of 208F. The inverter would be the part to worry about, especially if the battery was discharging/charging a lot.

Wayne

 

I wonder how many grill blocker users are unknowingly cooking their engines?

 

<div class='quotetop'>QUOTE(efusco @ Mar 14 2007, 08:20 AM) [snapback]405360[/snapback]</div>

I'm going on a long trip in about a week and a half. I think I'll leave the tubing on the grill just to see what the temperature gets up to. This will include some mountain driving. There hasn't been a problem in the past, but the temperatures are up quite a bit now. I can pull over and take it off in a minute, if it looks like there's a problem. I believe I mentioned that I saw the inverter temperature as high as 135-140 once. And I wondered if it was because I'd accidently (without knowing) gotten it into B for quite a distance. I've never seen it much over a 100 since then.

Dave M.

 

<div class='quotetop'>QUOTE(richard schumacher @ Mar 14 2007, 09:51 AM) [snapback]405340[/snapback]</div>

I don't think we're cooking anything. It was 70F yesterday going home and the fan didn't turn on.

 

My trip from up north to Florida last December went from subfreezing
gradually into 70+ as I got past Jacksonville, and I kept an eye on
the temp since I can. My fans didn't even try to turn on either,
but once it hit 70F ambient I stopped and opened up the lower grill
blocker which is configurable. Now, this was mostly interstate
travel on the flat, so the conditions may have been different.
.
On the other hand, every once in a while I smell antifreeze vapor,
and I know that a very small trickle can escape from *somewhere*
under high sustained loads. I still haven't found it other than
a very vague hint of a dribble down under the passenger-side radiator
hose fitting, and the coolant level hasn't appreciably dropped over
20 or 30 thousand miles of occasionally smelling that, so I'm not
particularly worried. But if all the cars perhaps do the same sort
of tiny antifreeze dribble from somewhere, that might have been
your "burnt" smell. [Sometimes it comes from *other* nearby cars,
too...]
.
_H*

 

I've been reading these grill blocking threads.

As I understand it the only reason is to keep the engine warmer in very cold temps. There is no aerodynamic benefit at all.

So if I'm reading these right, there is little benefit for me to do this, except perhaps in the coldest days of our So.Cal winter. When I leave for work in the morning in Jan it can be in the 40s.

It's still in the high 50s low 60s in the mornings now but the afternoons are in the 70s. So if temp is the only reason, no reason for me to do this really.

Right?

 

In short, right.

I don't fell well at the moment, so if you want the long answer, let me know and I'll give you a longer answer. Or try to, anyway.

 

Hi Tideland,

What did the smell smell like ? Was it like a burning dust smell, like the first time you turn on a forced-air heating system in the winter? If so, that might be the electric heaters coming on. Or did it have a phenolic smell to it? Like burning enamel? If it had the phenolic it could be motor wiring in the ventilation motor, or worse outgassing from the transmission vent. You said there was allot of snow, and probably melt and refreeze blockage. Its possible the ventilation fan was not getting any flow and was overheating. That would jive with your frosted up window observation. If you switched to recirculation the ventilation motor would get flow, and the smell would go away, but the smell from transmission venting would go away too. So, go to recirc, till the smell goes away, then back to outside air with the ventilation fan speed low, and see if you get any smell. If you do, then its probably coming from the engine compartment somewhere.

 

Godiva, blocking the grills keeps the engine warmer. (I presume that was a typo.) At 40F--70F I don't think you'd see much improvement.

For me, it gets my first bar somewhat above 25mpg and my 2nd bar around 50mpg. The engine will actually shut off at a stop during these ten minutes. If your engine doesn't idle and your mpg is there already you can save a trip to Home Depot.

 

have to admit, very little major climbing... lots of small stuff and Tuesday, did over 120 miles of driving including two stretches of 40 miles at freeway speeds. temps in low 70's. no issues. in fact, check out my last tank. that one day raised my tank average nearly 3 mpg!! with those low temps you had Jonathan, i doubt that anything burned up.

 

Jon were you following another vehicle up the hill? It could have very well been another car with an over heated cat. Audi in particular. I doubt that on either Seymour or Cypress your going to run into any trouble going up them. Even with the grill blocked upper and lower there is still the openings under and behind the spoiler to allow the cooling fans for the inverter to get air. Same for the ICE fans, same fans but different temp sensors switch them on if needed. Three in the car and defrost on will leave a lot of moisture in the A/C system and sometimes it takes forever to clear the windshield. Especially when coming down either of those hill the ICE will hardly ever run. Both are just over 3000' 1000meters in a bit over 5 miles so do the math.

 

<div class='quotetop'>QUOTE(FireEngineer @ Mar 14 2007, 10:50 AM) [snapback]405339[/snapback]</div>

Trust Wayne. Wayne knows.

I've also found that the electric cooling fan cools the engine very quickly when the ambient temperature is very cold, even if the front grilles are completely blocked. My wife likes to drive at illegal speeds and would often get the temperature up to 206-208 when driving around 80mph sustained. (I love that the ScanGauge shows trip history data for coolant temperature as well as maximum mph and rpm.) I then stress tested the cooling myself by driving up a long hill at 80mph and saw (with the scangauge) that as soon as the coolant temperature reached 206F, the cooling fan quickly brought it back down.

I only have a Scan Gauge and not a CanView, so unfortunately I couldn't track the inverter temperature. I removed one of the strips of insulation blocking haly of the top grille and then found that the engine temperature would hardly exceed 191F. Now that temperatures are starting to rise, I've opened the lower grille and only have the top grille blocked.

<div class='quotetop'>QUOTE(richard schumacher @ Mar 14 2007, 10:51 AM) [snapback]405340[/snapback]</div>

I wouldn't dare block my grille without monitoring the engine temperature closely. Of course I may be cooking the inverter or other hybrid components unknowingly. I watch the engine coolant and air intake temperatures closely. As long as they are below what I'd observe with an open grille on a hot summer day, I hope the hybrid components are safe.


<div class='quotetop'>QUOTE(Godiva @ Mar 18 2007, 05:12 PM) [snapback]407987[/snapback]</div>

The Toyota/Car & Driver team that modified a Prius for a speed record on the Bonneville salt flats blocked the grilles (and body gaps) to improve aerodynamics to achieve their highest unofficial speed. I suspect that blocking the top grille has greater benefits than blocking the lower grille and that the aerodynamic benefit of either is quite small. I'm more interested in keeping the engine at an efficient and safe operating temperature, even in frigid temperatures and with a need for cabin heating, without burning additional gas just to keep the engine running and warm.

 

<div class='quotetop'>QUOTE(Godiva @ Mar 18 2007, 01:12 PM) [snapback]407987[/snapback]</div>

in a realistic sense, no there is not. however, its been well known that blocking the front grill does provide reduced drag and an areodynamic benefit and any NASCAR professional will tell you that. it is also a fine balance for them as to the amount of grill blocking and temperature control will last the entire race.

you hear about engines blowing up all the time right?? not as much now as in the past, but 99% of those blown engines simply blocked too much of the grill and got too hot and blew up.

for time trials that are only a few laps, grill blocking is usually 80-90% and the crew chief is betting that the race will be over before the engine blows. it can get another 1-2 mph top end out of the car. for a regular race, usually blocking is capped at 40-60%.

if in doubt. take a paper bag, open the end and wave it around, open end first. you can feel the bag being blown up. increased drag. now close the end of the bag, wave it around, much less drag right?? extreme example, exact same priniciple. drag is caused by air that DOES NOT get redirected smoothly AROUND an object. every, vent, hole, dimple, etc...all causes drag or turbulence or both

 

Actually there is one advantage to blocking the grill- last summer a nice stone came through the grill and punctured the air compressor - over $700 later - after having to drive 150 miles to the nearest Toyota dealer with the part in 105 degree weather with NO A/C.... poor design...