How to install a cold air intake

Dirty Dog

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On todays episode of Getting Dirty with the Dog, we're going to install a Cold Air Intake.

I'm your host, Rowdy, the Best Dog in the World. I let the ugly guy do the wrenching though. Because he has thumbs.
IMG_3354.JPG IMG_3380.JPG

This is Thor. A 2013 Jeep Wrangler Unlimited Rubicon. He was purchased August 17th in bone stock condition with 98,000 miles. In addition to the usual Rubicon bits, the factory included a black leather interior and an M6 transmission.

The temporary tags won't expire for another 3 days, but modifications so far include: Rough Country 5" suspension lift. Vijay front and rear bumpers with integrated LED lighting. Hooke Road fender flares and front inner liners. Poison Spyder Bruiser rock sliders. Smittybilt 10,000lb winch with wireless remote. Smittybilt pivot heavy duty off road spare tire carrier. Smittybily replacement hinges. Lights from Sunpie, Hooke Road, NiLight and YitaMotor. Voswitch JK 8 gang accessory switch system. Awesafe 10" touchscreen Android/Carplay headunit.
IMG_0829.JPG

Most will recognize this as the stock setup. It works fine, but it could certainly be better.
IMG_5508.JPG

One thing that doesn't show in the stock setup is the mess of crap on the bottom of the air inlet tube. While this stuff does serve a purpose, helping the engine breathe is not on the list.
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So let's get started. Much of this will apply to any Cold Air Intake, but we are specifically installing the Rough Country Cold Air Intake that I got from Amazon. I think gains from a Cold Air Intake are minimal, especially in a basically stock V6. So I am unwilling to spend upwards of $400 for the Airaid or K&N offerings. $150 sounds about right for something that will probably net 5-10HP.

The only tools needed are a ratchet, 8mm & 10mm sockets, a 4mm Hex wrench, and a screwdriver.

The first thing I did was unbox the intake. I know, you're supposed to video it and post it on YouTube, but I didn't.

The box includes all the parts needed. You will reuse the two 10mm bolts and the 8mm bolt you will remove from the radiator shroud, so hang on to them.
IMG_5510.JPG

To remove the factory intake, take out the two 10mm bolts holding the intake and the overflow hose to the top of the radiator shroud. As said earlier, you will be reusing these. And since they're 10mm, you will probably also have to go buy another socket after you lose the one you just used.

Use a screwdriver to loosen the hose clamp holding the stock inlet on the throttle body. Jiggle and tug till the intake tube comes off. Squeeze the tab on the connector for the Intake Air Temp sensor and disconnect it. Remove the rubber hose connecting to the air box. Mine was just a friction fit. The air box is held at the bottom by pins. Wiggle, jiggle, and pull a bit more and that will all come free. Turn the intake tube over, marvel at the mass of junk on the bottom, and then remove the Intake Air Temp sensor. You will need it. Just twist it counterclockwise and pull. It'll be stuck, so pull harder.
IMG_5511.JPG

Now assemble your new intake. Details of this will vary by manufacturer.

The Rough Country requires you to assemble the intake box. This involves using 6 hex bolts, washers, and locknuts to bolt together two pieces of steel. These and the intake tube have a nice textured black powder coating that should look and work well for many years. You then put rubber trim around the hole where the tube penetrates the box (cue the dirty jokes...) and where the box meets the hood. Insert the rubber isolator in the hole under the intake tube entry and bolt it in place. Put washers on the two long bolts and put them through the holes in the box. Grab the aluminum spacers, and take the whole mess over to your Jeep.

Right where your radiator fill is bolted to the shroud, there is a bolt. Use your 8mm socket to remove it. Don't lose it. Place the spacers over the two long bolts, then put the bolts into the sockets for the factory box. These are the same ones used for a friction fit on the OEM intake. Hold the box in the right place, and use that 8mm bolt you saved (you did save it, right?) to bold the side of the box to the radiator shroud.

Now go back to your bench and assemble to tube.

The package includes a rubber grommet. Place that in the pre-drilled hole at the curved end of the intake tube. Now remember that IAT sensor you saved? Grab it and push it into the grommet. Make sure the O-ring is inside. The grommet will want to push into the tube, so hold it from the inside. I found that a little lube helped (cue more dirty jokes...).

Place the provided rubber coupler and two band clamps on the curved end of the intake tube. Tighten the tube side clamp. And... back to the Jeep. Put the straight end of the tube through the hole in the air box. There's a slotted tab on the bottom. Put that over the stud sticking out of the rubber isolator. Push the rubber coupler onto the throttle body. Lube might help again. Tighten that clamp. Now realize that you need to connect the IAT wiring, and it probably would have been easier before you immobilized the intake tube. You can still do it, especially if you have tiny hands. Otherwise, loosen the clamp, remove the tube, attach the wiring and then re-install the tube. Put the washer and nut on the isolator and snug that down.

Use the supplied screw clamp to put the rubber hose on the intake tube. Use the other one to secure the cone filter in the box. Take a moment to congratulate yourself on switching to a product that can be washed and reused, thus protecting the environment.

Now remember those two bolts you put spacers on? The ones sticking down through the bottom? It's time to go put the nuts on from underneath. I don't know about the OEM liners, but with the Hooke Road inner fender liners, you will not be able to find the. Just remove the liners and it's easy.

The kit includes two hose clamps. Use them and the two 10mm bolts you removed from the top of the radiator shroud (I told you not to lose them!) to secure the overflow hose. It's been a few minutes, so it's possible you may have lost your 10mm socket again.

Apply the Rough Country decal to the intake tube. This is absolutely vital. Possibly the most important part of the process. There is no way the system will work without it!
IMG_5514.JPG

Put your engine cover back on (if you want...). Now put your tools away, clean up your mess, wash your hands, and fire that thing up. You will hear the difference when you rev it up. I honestly don't think my carefully calibrated Butt-O-Meter will register any difference in performance, but it's reasonable to expect 5-10HP from this.
IMG_5515.JPG
 
Last edited:
Very detailed and entertaining write up .
Thanks for posting .
My only concern would be water getting threw exposed filter
Thank you.
Water is always a concern regardless of the intake. On the other hand, water injection has long been a common practice in the boosted engine world.
The box it sits in is more open than the factory box, but the air is primarily entering from the grill and top. These types of filters can be oiled, which can help prevent water entry. But unless you're essentially submerging the engine bay, I don't think problems are likely.
I don't know about you, but one of the things I was taught to do in deep water is keep moving. That causes a bow wave to form, which in turn means the water level on the Jeep side is lower.
If you routinely go through deep water, a snorkel is probably a good idea, with the caveat that anytime the snorkel is not absolutely necessary, it should be disconnected. Snorkels rob your engine of power.
 
On todays episode of Getting Dirty with the Dog, we're going to install a Cold Air Intake.

I'm your host, Rowdy, the Best Dog in the World. I let the ugly guy do the wrenching though. Because he has thumbs.
View attachment 122519 View attachment 122520

This is Thor. A 2013 Jeep Wrangler Unlimited Rubicon. He was purchased August 17th in bone stock condition with 98,000 miles. In addition to the usual Rubicon bits, the factory included a black leather interior and an M6 transmission.

The temporary tags won't expire for another 3 days, but modifications so far include: Rough Country 5" suspension lift. Vijay front and rear bumpers with integrated LED lighting. Hooke Road fender flares and front inner liners. Poison Spyder Bruiser rock sliders. Smittybilt 10,000lb winch with wireless remote. Smittybilt pivot heavy duty off road spare tire carrier. Smittybily replacement hinges. Lights from Sunpie, Hooke Road, NiLight and YitaMotor. Voswitch JK 8 gang accessory switch system. Awesafe 10" touchscreen Android/Carplay headunit.
View attachment 122521

Most will recognize this as the stock setup. It works fine, but it could certainly be better.
View attachment 122522

One thing that doesn't show in the stock setup is the mess of crap on the bottom of the air inlet tube. While this stuff does serve a purpose, helping the engine breathe is not on the list.
View attachment 122530

So let's get started. Much of this will apply to any Cold Air Intake, but we are specifically installing the Rough Country Cold Air Intake that I got from Amazon. I think gains from a Cold Air Intake are minimal, especially in a basically stock V6. So I am unwilling to spend upwards of $400 for the Airaid or K&N offerings. $150 sounds about right for something that will probably net 5-10HP.

The only tools needed are a ratchet, 8mm & 10mm sockets, a 4mm Hex wrench, and a screwdriver.

The first thing I did was unbox the intake. I know, you're supposed to video it and post it on YouTube, but I didn't.

The box includes all the parts needed. You will reuse the two 10mm bolts and the 8mm bolt you will remove from the radiator shroud, so hang on to them.
View attachment 122524

To remove the factory intake, take out the two 10mm bolts holding the intake and the overflow hose to the top of the radiator shroud. As said earlier, you will be reusing these. And since they're 10mm, you will probably also have to go buy another socket after you lose the one you just used.

Use a screwdriver to loosen the hose clamp holding the stock inlet on the throttle body. Jiggle and tug till the intake tube comes off. Squeeze the tab on the connector for the Intake Air Temp sensor and disconnect it. Remove the rubber hose connecting to the air box. Mine was just a friction fit. The air box is held at the bottom by pins. Wiggle, jiggle, and pull a bit more and that will all come free. Turn the intake tube over, marvel at the mass of junk on the bottom, and then remove the Intake Air Temp sensor. You will need it. Just twist it counterclockwise and pull. It'll be stuck, so pull harder.
View attachment 122525

Now assemble your new intake. Details of this will vary by manufacturer.

The Rough Country requires you to assemble the intake box. This involves using 6 hex bolts, washers, and locknuts to bolt together two pieces of steel. These and the intake tube have a nice textured black powder coating that should look and work well for many years. You then put rubber trim around the hole where the tube penetrates the box (cue the dirty jokes...) and where the box meets the hood. Insert the rubber isolator in the hole under the intake tube entry and bolt it in place. Put washers on the two long bolts and put them through the holes in the box. Grab the aluminum spacers, and take the whole mess over to your Jeep.

Right where your radiator fill is bolted to the shroud, there is a bolt. Use your 8mm socket to remove it. Don't lose it. Place the spacers over the two long bolts, then put the bolts into the sockets for the factory box. These are the same ones used for a friction fit on the OEM intake. Hold the box in the right place, and use that 8mm bolt you saved (you did save it, right?) to bold the side of the box to the radiator shroud.

Now go back to your bench and assemble to tube.

The package includes a rubber grommet. Place that in the pre-drilled hole at the curved end of the intake tube. Now remember that IAT sensor you saved? Grab it and push it into the grommet. Make sure the O-ring is inside. The grommet will want to push into the tube, so hold it from the inside. I found that a little lube helped (cue more dirty jokes...).

Place the provided rubber coupler and two band clamps on the curved end of the intake tube. Tighten the tube side clamp. And... back to the Jeep. Put the straight end of the tube through the hole in the air box. There's a slotted tab on the bottom. Put that over the stud sticking out of the rubber isolator. Push the rubber coupler onto the throttle body. Lube might help again. Tighten that clamp. Now realize that you need to connect the IAT wiring, and it probably would have been easier before you immobilized the intake tube. You can still do it, especially if you have tiny hands. Otherwise, loosen the clamp, remove the tube, attach the wiring and then re-install the tube. Put the washer and nut on the isolator and snug that down.

Use the supplied screw clamp to put the rubber hose on the intake tube. Use the other one to secure the cone filter in the box. Take a moment to congratulate yourself on switching to a product that can be washed and reused, thus protecting the environment.

Now remember those two bolts you put spacers on? The ones sticking down through the bottom? It's time to go put the nuts on from underneath. I don't know about the OEM liners, but with the Hooke Road inner fender liners, you will not be able to find the. Just remove the liners and it's easy.

The kit includes two hose clamps. Use them and the two 10mm bolts you removed from the top of the radiator shroud (I told you not to lose them!) to secure the overflow hose. It's been a few minutes, so it's possible you may have lost your 10mm socket again.

Apply the Rough Country decal to the intake tube. This is absolutely vital. Possibly the most important part of the process. There is no way the system will work without it!
View attachment 122528

Put your engine cover back on (if you want...). Now put your tools away, clean up your mess, wash your hands, and fire that thing up. You will hear the difference when you rev it up. I honestly don't think my carefully calibrated Butt-O-Meter will register any difference in performance, but it's reasonable to expect 5-10HP from this.
View attachment 122529
 
Can only achieve a true cold air intake by using a snorkel. If it’s under the hood it a warm air intake
 
Had the afe setup on my 07 rubi and removed it after a month. Totally useless waste of time and money. Any power gain was unnoticeable and as far as sound it was a loud sucking sound from under the hood with no noticeable performance gains at all. As much as I hate it 3.8 and 3.6 engines are turds. Love my Jeep anyway
 
Can only achieve a true cold air intake by using a snorkel. If it’s under the hood it a warm air intake
If we're going to turn this into an exercise in pedantry, it's only a cold air intake if the intake air temperature is less than 46F.

Air entering the engine compartment from underneath is cooler than air coming from the top. A CAI is engineered to maximize the flow of air and prioritize the air coming from the coolest area.

And of course, cold air intakes do more than simply change the source of air. They also provide a smoother, more direct passage of air into the throttle body. Which means more air enters the combustion chamber. Which means more power. Is it a huge change? No, it's not, and nobody with any sense will claim it is.
But the most fundamental recipe for increasing engine output is More Air In + More Fuel In - Exhaust Gases out = More Power.
In this particular case, the CAI + Free flowing exhaust + more aggressive tune + a general tune up = 30-35HP. That's not huge. But on an engine that was only rated at 285HP to begin with, it is enough to matter. Every little bit helps.

If you'd like to exam the physics behind this, read up on Poiseuille's Law. It explains in excruciating detail why a long passage, such as a snorkel, will make less power than a short one, like a CAI.
 
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If you really think it helps that’s great brother. Not the first or last person to fall for useless mods. But hey that’s what makes the world go round. Enjoy
 
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Thank you.
Water is always a concern regardless of the intake. On the other hand, water injection has long been a common practice in the boosted engine world.
The box it sits in is more open than the factory box, but the air is primarily entering from the grill and top. These types of filters can be oiled, which can help prevent water entry. But unless you're essentially submerging the engine bay, I don't think problems are likely.
I don't know about you, but one of the things I was taught to do in deep water is keep moving. That causes a bow wave to form, which in turn means the water level on the Jeep side is lower.
If you routinely go through deep water, a snorkel is probably a good idea, with the caveat that anytime the snorkel is not absolutely necessary, it should be disconnected. Snorkels rob your engine of power.
Hey D Dog .Sorry for delayed response . I was more thinking along the lines of going
threw deep water obstacle at speed and having water push threw
grill and soak the filter .
We all have seen the hydro lock videos of guys that have done this . Personally
not really interested in the massive splash myself or submarining my Jeep.

Yeah cold air intakes have been a debate for many years .
My personal take. If the water line approaches stock intake inlet.
Your going to have computer & electrical issues. . As computer
and alternator is roughly the same height .
Never really liked the high snorkel and as I said if your submarining
there is a whole lot of other problems
I saw some pics awhile ago of a cowl cold air intake
Figured if I ever would probably go that route .
It's stubby so not intrusive .
 
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