Been having a low pitched moan coming from the throttle body.Im running a K&N fipk setup and checked all fittings and connections nothing. So tonight I took the throttle body off and cleaned it and in the process I noticed the black sensor on the side (plastic) has a small crack what is this and could this be my leak? Also been thinking of upgrading to a larger throttlebody does maf sensor need to be upgraded also? Im running a 99 5.4 any comments would be appreciated I was told that the moan is the intake itself but when i sprayed it down no throttle change so I dont think its leaking thanks

 

no stock MAF is calibrater for ur injectors upgrading the throttle body will not require u to upgrade the MAF? and that black sensor with the crack in it is the TPS... i dont know how it would be making a noise no air flows through or accross it... can u better speficy where the noise comes from.. it could be the runner control servo out in it

 

The sound is louder buy the throttle body its been hard to pin point it or else i would have it fixxed the only thing i know for sure is that its loud when the truck is warmed up but it doesnt do it all the time. Has me puzzled any help please? fastor150 what is the runner control servo?

 

Yes, you can upgrade you tb without doing a mass air meter. I put a mass air on my 2001 5.4 and it made a solid 15 to 20 hp form about 3500rpm and up, although i dont know if it was bcause of the larger meter or because it changed the a/f ratio. As to your hum, has it done it since you put the air intake on or is it new? And yes that is your throttle pos. sensor that cracked and no air is comming from it. If it is badly cracked and moves at all i would replace it and make shure you get the right voltage from it.

 

yeah, I didnt know his truck had variable runners?

 

No the humm didnt start with the air intake happened about a month ago on and off now its on more than off. I just recieved my new throttle body today ordered the sensor pick it up in the morning cant figure out this noise ?

 

windsor engines do.. if u look on the lower intake manfold u will see the control servo its on the front

 

can u feel any vibration.. get a stethescope and try to locate the humm

 

Figure this out after cleaning the throttle body and putting it back together no humm ? I cant believe it was just a dirty throttle body Im gonna drive it awhil and see what happens. I put about 75 miles on it since I cleaned it I guess we shall see. What does the control servo do I was trying to find it do you have a pic of the location on a 5.4?

 

If it sounds like a foghorn, it is the IAC. I have a 4.6L that did the same thing, replace the IAC and you should be good to go. Do a search for "foghorn" and you'll see this is not uncommon. Good luck!

AMMOEATER

 

thanks ammoeater ill check it out thats exactly what it sounds like!

 

I am still unclear what you mean. When I think of a runner control servo, I think of the servo that controls the runners on a variable runner intake. To the best of my knowledge no v-8 f150 has ever had a variable intake manifold. Older cobras, some aviators, fr500, SHO, i am shure I am missing some here but never a f150. Maybe you are thinking of something different. I cant figure out what they would control. I dont think there are 16 runners to control, or multi valves to open and close air to so please help me out cause im lost.

 

a mechanic told me thats what is was i never saw it with my own eyes i doubt thats what it is.. i think its a vacume sensor or something.. but its on the lower part of the intake manifold on the front... i beleive its thr windsor engines that have them