What's new
Ram Heavy Duty Forum

Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!

6.7 Engine Air Filter Confusion

What’s the easiest way to remove some of those slats?
Remove the plastic cover on top of the radiator so you can look down between the shutters and the radiator. Looking at the back of the shutters it pretty easy to see how they come out (the center part with the motor pops out). I removed 10 of them and didn't break any.
 
I found a picture of a 19’ (which should be the same). The grill is sealed all the way around with foam tape and has a partition in the bottom to stop air from coming from that direction so it’s pretty well sealed when the shutters are closed. I think I’m going to take a couple out on each side at the top and see if it has any effect. I would really like to know the parameters of the operation of the shutters to know what makes them open and close such as temp, speed, a/c,…whatever.
 
The shutters are there to improve CAFE numbers. They will open when needed to keep engine temp normal.
But I don’t think they open when the intake needs some air. If the shutters are closed, the only air coming into the intake is being pulled through the radiator from the back side. Had they installed an electric fan on the CTD like they did the Hemi, it would have suffocated it. I’m just wondering if the shutters are causing the problem with the air filter and possibly the regenerations also. I wonder if it makes the engine think the filter is more restrictive than it really is. I know they suck in what ever air they need and adjust the fuel to optimize the mixture, but if you add up the square inches in the cracks and gaps, that’s not very much.


Your not having any regen problem in cold weather, with the slats removed, points to it needing cooler air.
 
But I don’t think they open when the intake needs some air. If the shutters are closed, the only air coming into the intake is being pulled through the radiator from the back side. Had they installed an electric fan on the CTD like they did the Hemi, it would have suffocated it. I’m just wondering if the shutters are causing the problem with the air filter and possibly the regenerations also. I wonder if it makes the engine think the filter is more restrictive than it really is. I know they suck in what ever air they need and adjust the fuel to optimize the mixture, but if you add up the square inches in the cracks and gaps, that’s not very much.


Your not having any regen problem in cold weather, with the slats removed, points to it needing cooler air.
It sure can't hurt to get colder air in. This would also allow the CAC to remove more heat from the air entering the engine (more dense air charge). I have never had regen issues in the winter even before removing the shutters.
GM added the hood scoop for the Duramax to get colder air into the engine (and avoid under hood air from getting in) so they could raise tow ratings without having to reduce engine power due to high air inlet temps while towing. Maybe Ram should look at something like this.
 
Ram went to hood scoops for the TRX instead of the Ram Air that we have. The TRX only makes up to 11.6 pounds of boost. Granted it turns more rpm but it would have to turn three times as many or more to equal the amount of air going through the Cummins. The filter size and flow rate are proven for this engine over many years. The problem has to be from the filter forward toward the air intake. I got out there today to try to figure out where I could be wrong about this. To try to figure out where else it could get air from if the shutters closed. There is none. I can’t find out what or when makes the shutters close but mine won’t do a passive regen below 80 mph. The shutters operating at highway speeds may help with keeping the water out if in the rain. There’s a good amount of air goes into the intake even at an idle with no boost. I can only imagine how much is being pulled in at 2000 rpm and 30 pounds of boost.
 
The shutters are there to improve CAFE numbers (aerodynamics). They will open when needed to keep engine temp normal.
The shutters have nothing to do with CAFE as that doesn’t apply to HD trucks. They do help with aero though, and with engine warmup.
 
The shutters have nothing to do with CAFE as that doesn’t apply to HD trucks. They do help with aero though, and with engine warmup.
You are wrong. CAFE standards started affecting 2500/250 and above as of the 2014 model year and got worse in 2018 for the 2019 model year.Screenshot 2023-11-23 at 18.20.16.png
 
You are wrong. CAFE standards started affecting 2500/250 and above as of the 2014 model year and got worse in 2018 for the 2019 model year.View attachment 65722
That was a proposal. No such rule was ever implemented. Vehicles with a GVWR of over 8500 pounds remain exempted. This is why you don’t see fuel economy numbers on the HD window stickers.
 
That was a proposal. No such rule was ever implemented. Vehicles with a GVWR of over 8500 pounds remain exempted. This is why you don’t see fuel economy numbers on the HD window stickers.
You have an outdated idea of CAFE. The EPA changed what is covered under CAFE under Obama. It's not just fuel economy now, it also includes things like carbon emissions and it applies to all vehicles for on road use. It was also suppose to apply fuel economy to to medium and heavy duty trucks but then president Trump's admin got a court to stay that part (the emissions part still applies). An appeals court upheld the stay in 2020. The current EPA has been trying to get the court order overturned but so far has been unsuccessful. The shutters were added to the HD trucks to help emissions and fuel economy thinking the CAFE rules would apply and not be stayed by a court order.
 
You have an outdated idea of CAFE. The EPA changed what is covered under CAFE under Obama. It's not just fuel economy now, it also includes things like carbon emissions and it applies to all vehicles for on road use. It was also suppose to apply fuel economy to to medium and heavy duty trucks but then president Trump's admin got a court to stay that part (the emissions part still applies). An appeals court upheld the stay in 2020. The current EPA has been trying to get the court order overturned but so far has been unsuccessful. The shutters were added to the HD trucks to help emissions and fuel economy thinking the CAFE rules would apply and not be stayed by a court order.
Please post a link to the new CAFE standards that have been implemented for heavy duty trucks.
 
Ram went to hood scoops for the TRX instead of the Ram Air that we have. The TRX only makes up to 11.6 pounds of boost. Granted it turns more rpm but it would have to turn three times as many or more to equal the amount of air going through the Cummins. The filter size and flow rate are proven for this engine over many years. The problem has to be from the filter forward toward the air intake. I got out there today to try to figure out where I could be wrong about this. To try to figure out where else it could get air from if the shutters closed. There is none. I can’t find out what or when makes the shutters close but mine won’t do a passive regen below 80 mph. The shutters operating at highway speeds may help with keeping the water out if in the rain. There’s a good amount of air goes into the intake even at an idle with no boost. I can only imagine how much is being pulled in at 2000 rpm and 30 pounds of boost.

It’s impossible to compare boost to airflow on different engines, as there are lots of variables. In general gas engines run more valve lift and that means less restriction, so 11.6 psi of boost on a gas engine is a lot more airflow than 11.6 psi on a diesel… in general.

Another example, when I put a Garret Turbo on my 05 the peak boost dropped but airflow increased. Then with the Colt Cam in my boost dropped again, but airflow also increased. Boost is just a measure of restriction. With both of those mods I decreased restriction thru the motor and even thou airflow went up the boost pressure dropped.
 
DPF requirements started in 2008. The company I was working for bought every 2007 class 8 truck they could find. Even bought a bunch of Freightliners with crappy Mercedes engines to keep from having to abide with it as long as they could.
 
DPF requirements started in 2008. The company I was working for bought every 2007 class 8 truck they could find. Even bought a bunch of Freightliners with crappy Mercedes engines to keep from having to abide with it as long as they could.
GPF is likely coming to a gas powered car/truck soon. Already being used in Europe. If true then gas powered cars and trucks can look forward the same issues being caused by DPFs in diesels.
 
We’ve talked about GPFs here before. They’re far less troublesome than DPF systems because gasoline engines generate plenty of heat to keep them burned clean.
 
Ok. The official word is that the FleetGuard AF27684 is outsourced from Wix who is now owned by Mann-Hummel. MH has dumbed down the quality so bad that NAPA is reported to be changing suppliers for their Gold filters. MH also owns Purolator and some others. Probably why the other filter had a Purolator number on it. Mopar gets a lot of their other filters from Purolator so don’t know how long the 53034051 AB will be in existence. Crazy days.
 
From what I’ve read, Mann filters are still quality filters while their other family brands are crappy.

They (MH) are a Germany based company as well as the faulty MAF sensors are. Coincidence, maybe. Interesting, definitely.
 
Last edited:
Back
Top