Question about drilling holes on air filter case

[DannyB]

I've drilled holes (actually the damn thing broke and now there is one big hole about 3x4)on my 96 4.0. However, Is there a problem with the engine "sucking" up HOT air from the engine compartment? Wouldn't hot air produce a better combustion? I have not noticed any difference on MPG or power, however on very hot days (recently) I've noticed a constant "howling" noise from the front right. I noticed that it does that when the outside temp is about 99+. It did not go away when I opened the air filter latch and separated the casing for a few seconds. Any ideas about the noise or opinions about the "hot air intake"?

[This message has been edited by DannyB (edited 05-21-2000).]

 

[ERIC]

I assume you punched the hole in ahead of the filter? I have a very similar sized hole in the air box ahead of the filter and have no howling noise. However, i also have a K&N filter which allows a much increased air flow. Are you still running the stock filter? If so, that may be the constricted paper filter making the noise.

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ERIC H.
'96 XLT
"You can run, but you can't hide...my dogs track."

 

[Isles4evr]

Paul, where did you fina a K&N for $25? The cheepest I've seen in $37+$3 for shipping!

Thanks,
Chris


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'91 Explorer 2dr

 

[Turner55]

i have a problem concerning the airbox...i cant get the freakin thing unscrewed...one screw i can get out, but the other has about 1/2" of slack and then wont come up anymore...will not back out. i need to get into there b/c i dont know the condition of my filter. how long does a regular filter hold up?

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'93 explorer sport 4x4
splitfire wires
bosch +4 plugs
hella 530 foglights

 

[1hotjava]

I have cut out about as much of the lower part of the airbox as I can without weakening it too much. Im not too worried about the warm air as much as I was about the restrictive nature of the design. It makes the engine a bit louder at full thottle, but did give me a bit better pull in the 2000-3000 rpm range. And it only cost me the time to cut it out rather than $200 for a custom cone setup (I already had a K&N filter in the box that cost me $25.)

-Paul O.

 

[DannyB]

Hi Eric, Yes the cut is ahead of the filter (on the same plastic part that has the "intake" hole going into the fender side).
and yes, I'm using the original filter, your theory on the paper filter makes sense, however what have me puzzled is that when I opened the filter box and separated it, I had expected the "howling" to go away but it didn't!!! Just for kicks, this evening I temporarly patched the hole with duct tape to see if the noise goes away... We'll see . . .

 

[DannyB]

Well, no howling noise today. However, the temperature today here in Los Angeles is only about 72F and cloudy. It's supposed to be partially cloudy and into the 90's on Saturday and we'll know then.
(GREAT!!! Now I'm also doing the weather report!!!)

Thanx Eric.

 

[ERIC]

DannyB,

If you decide to keep the airbox sealed up, DO still consider the K&N filter. I can all but guarantee you'll feel a better throttle response, airbox cutout or not. Good luck.

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ERIC H.
'96 XLT
"You can run, but you can't hide...my dogs track."

 

[ERIC]

Danny B,

Covering the hole to see what happens seems like the next step, I agree.

However, even if it does go away, consider this. With the paper filter in and the air box locked up, you may be hearing howling as the filter is strained. With the air box open, you may be hearing howling from the now-wide-open air channel.

Unfortunately, the only easy resolution to this is to pop for the K&N or similar filter. FWIW, I think the the K&N gives a bigger boost in power than cutting out the air box anyhow. It seemed to on my 96. If i could only do one or the other, I'd go for the K&N. BTW, I had the K&N in before I cut out the box, and altho the K&N resulted in a noticeable increase in response, the cut out didn't.

Anyhow, please post back with the results of closing the hole in the box.

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ERIC H.
'96 XLT
"You can run, but you can't hide...my dogs track."