I have a 2001 ford f-150 4x4 lariat ext cab with a 3 inch body lift and running 35-12-50 bfg mudders on 17 inch rims 17 by 10 american racing.. MY PROBLEM !! IS this truck has been perfect not a bolt turned on it not one single problem UNTILL a few weeks ago i went thru a very bad hole and like the big dummy i am i decided i could do it in 2 wheel drive and got stuck the truck never bogged down it lost power the starter filled up with water and the truck shut off.. well after i got it out 3 hours later and towed home and a new starter installed it started right up but then my transmission started leaking.. it was full of water and blew out the seals got the tranney fixed all new seals put in.. got the front and rear transfer cases relubed with new gear oil (syn) all is back to normal except.. now the truck roars really bad it sounds like a damn semi when it starts up and it kinda feels like it has lost some of its power ( not much ) can some one out there tell me why im roaring so loud now...

oh yes i almost forgot to tell that i did replace the fan clutch and i did clean out the cooling system (rad)

please my ears r open

 

what exactly does it do when you start it? i know you said it roars,but does it just rev high for a minute or does it mis,sound like a diesel or what? if it sounds like a diesel and misses it could be a plug misfiring because it has moisture inside the cop boot or could be a clogged cat.if the exhaust has a rotten egg smell to it its one of those 2.the misfire will dump more unburned fuel into the exhaust making the cat glow red hot and smell like that and make you think its stopped up or the cat could actually be stopped up if you got water in the exhaust.you also will definitely wanna chang your oil if the engine was in any water cause that will tear up all kinds of *****.so change it and put some marvel mystery oil in place of one quart and run it for a while and change it again if you haven't to clean anything out you can.and check your o2 sensors if they were in water.i'm guessin everything was submerged if your starter was so it could be all kinds of things.

 

way fast it dont sound like a diesel at all it just roars kinda sounds like you got your foot on the gas when it starts up.. the oil was changed before the truck was ever started back up .. once you get going the roar stops.
only does it at start up and when taking off like a red lights and such..its realy driving me crazy tho i cant stand that loud roar.after replacing the fan clutch and still not fixing the problem im at a tatal loss on what it can be..
one more thing i have noticed it does now when i realy get on it hard you can hear a faint whining sound kinda sounds like i got a supercharger i have no idea man..........

 

ANY ONE ????????

 

Did you clean out the alternator after the mud bath? It can make the roaring sound. As for the loss of power your rear parking brakes may be binding from mud contamination.

Regards

Jean Marc Chartier

 

THANKS JMC I WILL CHECK MY alternator that is one thing i have not looked at....

 

ok i have cleaned the alternator and roar is still there !!! it sounds like my foot is on the gas pedal when it starts up still

 

Does it idle at the proper RPM when you start it up?

JMC

 

AFTER THE LOUD ROAR and it sits for a min or two and idles down a bit it does kinda sound like it might be idieing a touch high..!! on a lighter note tho while i was under it i did crank up my torshion bars all the way . took it out for a test ride and all is good still got that great ride ..but the roar is still there.

 

If that is the case I would suspect that the IAC is dirty and needs to be cleaned. Do you need instructions on where it is and how to clean?

JMC

 

yes i do im not sure what the iac is ?? dont mean to sound dumb but you got me on that one.

 

clean out your maf sensor too, kinda the same thing happenned to me but not as bad, if that dont work have someone start it with the hood up and try to get a better fix on the sound maybe buy a cheap othoscope, and probe around in there for weird sounds, maybe your fan is off ballanced or something too, just a sugestion hope it helps

 

OK I WILL CHECK THAT THANKS 311

 

STILL NOT SURE WHAT THE IAC IS ??? WHAT IS IT AND WHERE IS IT ?

 

EDIT: Picture correction

Sorry for the delay in getting back. Here is a diagram showing the location of the IAC on a 4.6. If you remove the black cover 3 8mm bolts you will expose the Intake manifold and all the other componants.

JMC