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Air Intake Removal How-To (2003 Astro)

37K views 28 replies 9 participants last post by  unkajoesplace 
#1 ·
The air intake I'm referring to holds your air filter, and has an intake by the air conditioner lines. Removal is simple and necessary for a number of procedures. To remove it, you'll need to do the following:

1: Loosen rear hose clamp and disconnect intake hose. For this you'll need a 1/4" drive rachet and 8mm or other appropriate size socket as your configuration may vary slightly. I couldn't fit a screwdriver here, even my short one...


2. Remove wires to sensors. These wires have clips that will need to be held open to be removed. Here are the wires I'm talking about:


3. The air intake is also attached to the fan housing in two places, and uses rubber fasteners attached to the fan housing by plastic. Your best bet to remove them is to work them through the air intake housing using a small screwdriver. The photos below will show the locations I'm talking about, but try to avoid what I did there...that's not what I was talking about with the screwdriver...



4. Then remove the air intake. It will take some maneuvering, so don't just yank it out...


5. This is what you're left with. As you can see, you have a little bit more access to some other stuff...


It goes back pretty much the same way it came out. General note, if you start your engine for any reason with it removed, you will get a check engine light as your sensors are not connected--it doesn't go away when all is back together. I did this after a belt change, and found that Advance Auto local to me will clear the error for free.
 
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#3 ·
if you remove both ends and cut out the center of the bottom of the intake box you get alot more air.
 

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#5 ·
speedy57 said:
Cowboydan do u have any pics of ur modifcation to the airfilter housing? Do u have any problems with the filter getting wet?
nope, but it's pretty simple. 2 cuts. the 2 ends just pop off. you might have to take out a couple screws, i cant remember. this is why i posted a pic in here. you can see how the box looks and then you can pick out the mod. i used a ryobi 5" cordless skill saw, then just file off the burs. as for getting wet..... i have been running this way for 4 yrs now. i'm sure i would have gone through atleast one storm in that time ;) i also don't have any snow issues. i live up north of most. we get some pretty crappy weather. this is a safe mod and i know it works. not complaints about my milage...lol i just checked my intake tube for oil on any sensors...i didn't find any resedue from my k+n. like i have said already, it's been done for 4yrs and i have put 35000km on in that time.
 
#7 ·
Sorry for chiming in on an old sticky but I wanted to pass along some info.

Popping the airbox sides (which I did) or replacing the airbox with a cone filter is probably one of the worse things you can to do the astro.

Now before you flame me, here is why. You are putting the air intake up above the grill with no moving air and nothing but hot air in the engine compartment after the radiator. Compounding the issue, the ECM pulls timing from the motor based on intake air temps. IAT's

I can backup this up with my data from the HPTuners stuff I run in the van. Over 120F in the IAT's the motor starts pulling timing, the higher the IAT's the more it pulls. I'm down in SWFL and in the summer traffic, I get IAT's over 130F

I can post the data from the spark table if you like.

And if anyone has the 2003 airbox sides they want to sell, I'll buy them. I tossed my before buying the HPTuners software.
 
#8 ·
lol. my van comes equipped with a fan shroud. it also insulates the rad. but if you feel the need to post up... i won't ask what your best milage numbers are though...lol. this is a mute point to me cause you are entitled to your opinion. i know it works. my milage or power doesn't suffer as a result of this mod. the hottest i deal with is 32 deg. i can also think of worse things to do... like leave it all stock. you do what you do and i will go on saving my money. no flames... their golfing right now.

hank, what are those numbers at the bottom of your post?
 
#9 ·
cowboydan said:
hank, what are those numbers at the bottom of your post?
Torque numbers off the trans sensor recorded from 1/4 mile runs using hp tuners. I don't have a dyno nearby so I have to go with what I've got.
 
#10 ·
what year is your van?
how are you running 97 octane? the most i see at any pump is 94 but that is e85 blend
what is the basic compression of your engine?

i think your 87 octane run is confusing. it almost seems as if there is less power in 87 octane. is this correct?
 
#11 ·
2003 AWD

The 97 octane may be a type-o. We have a station up the road that has 4 blends available on the pump. 89 - 96 or it may have been 98..

My 87 octane tune has a less aggressive spark timing table as I had a lot of ping to pull out when I switched fuels.

I want to clarify that I'm not knocking the airbox mod as it does make the engine breathe easier, however be aware that when it gets warm the ECM pulls a lot of timing..
 
#12 ·
i did some running data with my mac. i'm not seeing what your seeing. my intake temps are pretty equal to current outside temps. it does jump up in stop and go traffic but that's acceptable.

i think your tests are inaccurate. the higher the octane level, the more resistance to knock/ping

http://science.howstuffworks.com/gasoline3.htm.

running higher levels of octane generally produces less power... slower burn. boosted engines can not run 87 octane. high preformance engines of any kind use 91 and up because they have to, not because it's better. race gas is 106 and you can buy it at the airport. i have never heard of 96 or 98. i have seen 85,89,91,93,94.
 
#13 ·
Correct, I run a spark table with less advance when I run regular octane level fuel. Next time I'm up the road in North Port, I'll snap a pic of the pumps at this station. They have more than 3 choices for regular fuel. I usually top off there when towing.

Not sure where you are at but I can pull IAT's in the 129 to 134 range when driving around town. Yes, on open roads they to pull down to nearer to ambient.

The whole point of my comment was that when you suck hot air and cross the IAT of 120, the ECM pulls timing. If you want me to, I will gladly post the config data from my stock, performance and towing tunes.

And yes I'm producing more power with the higher octane fuel as I can run a significantly higher advance in the factory spark tables.

Take a look at www.hptuners.com for what the package can do..
 
#14 ·
if your messing with the spark tables then you are modifying. when you do, your torque curve should be different. just changing the muffler will do that. any mod you do will affect the powerband. all of your numbers show different numbers with the exact same rpm. that is what my concern is. i am already happy with the preformance and milage that i have. i still think your tq numbers are a bit low. try the same test when bar pressure is at 102kpa. then again at 100. use what ever gas you like, the effects will be the same. i'm just not convinced that running premium fuel to add a bit more time is the best choice for an engine that is only 9:1 compression. now if you get over 30mpg with this tune, then you are on to something....imo. sorry, i'm tough to convince. but then again i will never drive in the hot conditions you do. the max is 32c for me. i live north of the border in alberta.
 
#15 ·
Haha, 30 would be a dream in the Astro. Actually what I'm tuning it for is towing. I pull a 5000lb travel trailer frequently. Lots of Disney trips...

With the factory tune I get 8mpg and a max speed of about 62. With the high octane tune I run I get 10mpg and comfortably cruise at 65 with lots of reserve power. Once, accidentally, I looked down and was cruising at 73. Trans and motor run much cooler as well. A 170f t-stat and a huge cooler helped as well.

Yes, we are a little hotter down here..

I've done a lot besides spark timing. The HPTuners stuff is insane.

Here is the factory IAT timing pull table. You can see how aggressive the pull is. Using my tuning laptop to do this post, Old Win2k3 thing..
 

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#16 ·
last trip i logged 29.4mpg... granted, i'm not towing. there are lots of guys at work that have owned 1/2ton chevys' pulling 35' holiday trailers and they blew through $300 to go 500km. they all own diesels now. between you and me, i think you are going through enough gas... it may be worth considering. even an older diesel would be worth considering. when i'm done with my van i'm going for one. 4 more years before i can go shopping. that's when my son will get his learners permit and then i'm putting him in my gn. by that time it will be a full race car. at that time i will get him certified for dragracing. i'm not towing my gn around with the van.
 
#18 ·
Hank said:
lol, actually crunching the number for the type of camping we do it looks like its better to buy a hyundai hatchback and a class A motorhome...
if the motor home isn't diesel, not much changes. diesels are ment for towing. do you have a pic of your airbox?
 
#19 ·
Yes would be diesel but a whole heap would change if I parked the Astro. It costs me 7.00 a day to drive to work. I borrowed a Yamaha Morphous 250 scooter from a friend and have been driving that lately. The hatchback would be a good split between the van and the scooter as it tends to rain down here right when I get off of work.

Airbox is the same in the photos at the beginning of the thread. The factory black plastic one.
 
#20 ·
so... same as the 1st one except you pulled the intake tube and the resinator?
 
#22 ·
you know, when i removed just those items, i found it to be worse than stock also (no numbers). that is why i made this mod. it's much better with the mod. opening up the front of the box changes how the air flows. path of least resistance.
 
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