Active grill shutter experiment

Before performing this mod, I had removed most of the shutter slats without generating a CEL. I removed the entire assembly and inserted the SS deck screw as described by the OP and for a few days of around town driving no issues.
I just returned from a 380 mile trip and also no issues. I did notice that coming up on a traffic slow down on the interstate, even with most of the slats removed, the coolant temp would rise by at least 10 degrees, often more, and slowly drop once under way again. (I'm running a 180 degree T-stat) With the assembly out entirely, the coolant temps did not rise in a slow down situation as dramatically, and dropped faster once underway again.
I've also read that the shutters tend to remain closed, even while steady-state cruising with minimal throttle input, and open (at the slow rate of the dc motor) when accelerating. They close again with light cruising throttle. They may open if coolant temps get really high (as in above 220 F degrees , but I've not been able to confirm that.
In any event, the assembly will remain out until and unless a CEL is generated, as giving the radiator, AC condenser and trans cooler full access to pressurized air flow while underway has to be better than periodically blocking that flow.
Finally, I've seen zero fuel usage increase with the assembly removed in highway cruise conditions. In fact on this last trip, with the assembly removed, and with MDS turned off, I saw the highest hand calculated fuel mileage ever, 22.8 mpg; and that was while cruising between 70 and 75 mph.

Modern engines are designed and prefer to run at higher temps than old V8's. My 2003 F150 was custom tuned with dual exhaust, electric fans etc. and my primary fan was set to come on at 210 with the secondary at 215. That Motor would not overheat until 230 plus degrees and it is a 14 year old truck. Technology has come a long way since then.

grizzstang said:

If they open at a certain temperature then what advantage will be gained from removing them? Or do they open and close based on speed? Anyone know?

Edit: I just read a post by a Ram Tech that the PCM opens and closes them using a combination of temp and speed. It should work very well in my climate.

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From what i know the AGS is to boost fuel economy. When the MDS kicks in it shuts the slats to redirect airflow back out and below the truck.

I forgot what percentage the fuel increase is.

I personally think its stupid so what i did since im running a varram inatake, i took off the entire AGS assembly an removed all the slats except the top and the very bottom one. I bolted in back and been running like that for about 8 months now.

I run slightly cooler and i live in Texas and it gets 100 degree's out here.

At roughly 160 miles yesterday I had a code pop-up,cleared it and it popped back-up again at roughly the same milege,plus I didn't notice any change in my temps,so i'm re-installing the shutters.For you guys down south in the real hot climates,there might be an advantage to having the shutters removed,but for us Canucks,i'm not sure there's any advantage.

Wild one said:

At roughly 160 miles yesterday I had a code pop-up,cleared it and it popped back-up again at roughly the same milege,plus I didn't notice any change in my temps,so i'm re-installing the shutters.For you guys down south in the real hot climates,there might be an advantage to having the shutters removed,but for us Canucks,i'm not sure there's any advantage.

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If the CEL come on it's because the arm on the module is either travelling too much or too little. So your screw setup might need a little adjustment.

I'm not saying do this mod, but for those who want to do it it's possible. It might need a little adjustment to prevent the CEL, but do like me and mount it temporarily just in front of the fuse box for easy access.

I'm in Montreal Canada and we can get temperature ranging from -40 to over 100 F depending on the season, so for me I can see an advantage in the hot summer days when towing our camper.

You can always get this for the winter, but it's not an option for me since I want a lightbar behind the grill

bassheadhemi said:

If the CEL come on it's because the arm on the module is either travelling too much or too little. So your screw setup might need a little adjustment.

I'm not saying do this mod, but for those who want to do it it's possible. It might need a little adjustment to prevent the CEL, but do like me and mount it temporarily just in front of the fuse box for easy access.

I'm in Montreal Canada and we can get temperature ranging from -40 to over 100 F depending on the season, so for me I can see an advantage in the hot summer days when towing our camper.

You can always get this for the winter, but it's not an option for me since I want a lightbar behind the grill

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I'm guessing you still have the original Sport grill in your truck.My temps dropped when I swapped the stock air blocking Sport grill for the better flowing Honeycomb grill that comes in the lower level Express / ST style trucks,and R/T trucks . Honestly I didn't see any change in my temps pulling the shutters,but I did have a noticeable drop in temps when I swapped grills.This mod might be a mod that works better with the Sport grill that doesn't allow as much air through the front then it does with the Honeycomb grill that allows more air to flow through the grill.As it stands with no drop in temps,i'm putting them back in though,lol

I have had this mod done for roughly 500 miles now..... All good with no CEL.

Wild one said:

I'm guessing you still have the original Sport grill in your truck.My temps dropped when I swapped the stock air blocking Sport grill for the better flowing Honeycomb grill that comes in the lower level Express / ST style trucks,and R/T trucks . Honestly I didn't see any change in my temps pulling the shutters,but I did have a noticeable drop in temps when I swapped grills.This mod might be a mod that works better with the Sport grill that doesn't allow as much air through the front then it does with the Honeycomb grill that allows more air to flow through the grill.As it stands with no drop in temps,i'm putting them back in though,lol

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Already have the honeycomb one since I have the Tradesman model. In my case the main goal wasn't to get more air, but to remove them because they were getting stuck close. Now that the assembly is completely gone there's room for a light bar or even an intercooler.

It's not a mod for everyone, but now there's a easy way to do it for those who need/want to remove them.

Did someone say INTERCOOLER?!

RLJ10X said:

Did someone say INTERCOOLER?!

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Speaking of that,the Eco-Diesal trucks use a smaller set of shutters to clear the intercooler.Noticed that on the Eco-Diesal truck that we put my old Sport grill into,also thought ,hey there's a bolt-in factory intercooler that fits a 1500,lol

Well after over 2000 miles the CEL never came on so it's time to permanently install the module back behind the grill.

As for the fuel economy, did 23mpg (average calculated) on a 650 miles trip. For reference our 2007 Dodge Grand Caravan (3.8L) was doing worse than this for the same trip (19-20mpg).

Ok you got 23mpg average??? With 3.92s


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crazykid1994 said:

Ok you got 23mpg average??? With 3.92s


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Yes, running the HF91 tune with MDS off. I'm sure I could get a little bit more out of it on a flat road. This trip most of the time the cruise was set a 62mph (55 limit). Computer was giving 24.5mpg average

In the city, well the truck doesn't do so well (driver is the issue), computer is telling me 14mpg, but it's more like 12mpg.

bassheadhemi said:

Yes, running the HF91 tune with MDS off. I'm sure I could get a little bit more out of it on a flat road. This trip most of the time the cruise was set a 62mph (55 limit). Computer was giving 24.5mpg average



In the city, well the truck doesn't do so well (driver is the issue), computer is telling me 14mpg, but it's more like 12mpg.

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Highest I can get is about 20mpg on the evic with mds off that's doing 60-65... with 3.92s. Guess I need to get a tune


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crazykid1994 said:

Highest I can get is about 20mpg on the evic with mds off that's doing 60-65... with 3.92s. Guess I need to get a tune


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Well if that's running with regular 87, the price difference for the 91 will eat all the saving for those extra mpg. I don't know in the US, but up here ethanol free 91 is normally 16% more expensive than 87 (up to 10% ethanol).

bassheadhemi said:

Well if that's running with regular 87, the price difference for the 91 will eat all the saving for those extra mpg. I don't know in the US, but up here ethanol free 91 is normally 16% more expensive than 87 (up to 10% ethanol).

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That's running 89 ethanol I do have a carven muffler. When I installed that I lost some mpg. I used to see 25mpg doing 60-65


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To add another data point, I've also got close to 2000 miles logged since doing this mod. No issues. I have the motor module bolted to nice convenient, out of the way place to the left of the radiator near the top of the grille. My mileage has remained as it was prior to completely removing the shutter assembly. With MDS turned off (via the paddle shift switches), I typically see between mid 20's to mid-21's in MPG. Thats with 3.92's and cruising between 70 and 75. Saw 22.4 MPG on a 175 mile trip when I kept my speeds between 65 & 70. I am not tuned.
These results really make me wonder just how incrementally small the "alleged" fuel economy increase the shutters yield. Given my experience, I have to conclude the only reason for them is for an additional thermal management variable, with any fuel economy increase measured in the tenth of a MPG or even less.

Sorry to bump an old thread, but is it possible to remove completely the whole assembly and have the code tuned not to come on or any cel?

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Tmemz said:

Sorry to bump an old thread, but is it possible to remove completely the whole assembly and have the code tuned not to come on or any cel?

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No idea if it can be tuned out, it wasn't in the past, but maybe now it's possible.

FYI I'm still running this mod without any issue

Tmemz said:

Sorry to bump an old thread, but is it possible to remove completely the whole assembly and have the code tuned not to come on or any cel?

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Yes, contact your tuner. I completely removed mine, did the screw trick, and had it tuned out for good measure