hey guys im new trying to get some help first...

ok i have a 95 Ranger with a 4.0 in it ok when i drive it for about 30-45 minutes it will make a loud HUMMMING sound sounds like its coming from the MAFS but im not sure i know its not the air filter or anything so think its the MAFS? i also get bad gas mileage and it kinda "studders" when im driving sometimes

thanks

also it doesnt do it when its cold outside? and if i do have to replace it the cheapest i can get it is 230$ =/

 

I got a refurbished one at autozone for half that for my 3.0L. If the maf was bad it would most likely throw a code.

I'm not really sure where the humming sound would be comming from, maybe someone else will chime in.

 

Welcome to R-F!

Do you have a check engine light on? If so, take it to your local Autozone or Advance Auto Parts, they'll scan for free and tell you what's wrong.

Also, is it possible to record this humming sound and upload it on here? when a vehicle makes a humming sound, that's a broad statement but you've already narrowed it down to the engine so that's a start.

I'm with nbro, if the MAF was bad it would throw a code triggering the check engine light. -Mike-

 

ill try to take a video when i get off work today and post it

nope the check engine light is off

BTW im almost poistive its coming from the MAFS because i can disconect the pipe from it while its running and it stops

 

The IAC valve is what normally causes a humming noise, not the MAF sensor.
You can try cleaning it, but normally they have to be replaced.

 

whats a IAC valve? and wheres it located? sorry ima noob

 

take off the top cover on the engine, the big silver circle is the IAC
I think its the same on OHV as SOHC?

 

Here is a picture of the IAC. It's on my 3.0L, but the one on the 4.0L should look similar. It's located on the upper intake next to the throttle body:

 

ill put one of those on and see if thats it if not im going to buy a new MAFS

 

i g2 replace mine. i cleaned mine and it started to hum and now after about 2 weeks of driving like that it just threw a code today lol.

ya if its humming its the IAC not the MAF

 

Been there done that!! Mine used to do it bad, but thanks for R-F i figured out the problem!

 

ok i was wondering something if it is the IAC valve would it echo down through the intake pipe and sound like its coming out of the end? around the MAF? i mean it gets LOUD at the end by the MAF and filter



well pulled the IAC off the stuck my finger in one of the holes and i got a black gummy oil on my fingers? is that normal? i dont think it is how do i go about cleaning that? also the IAC valve is ony 60$

 

blast out the the iac with carb cleaner, dry it well, then re-install and see what happens...

 

i did that .... still does it but i went to parts america and they have two for my model ? does it matter what one i put on it?