Ok so my grandpa has a 2002 F150 with the 4.6L V8.. Its got 102,xxx miles... He only lets Ford work on his truck.. But he started having problems a few days ago... the Idle will drop from around the normal 800 RPMs to 400 or 500 RPMs and then go back up and his Check Engine light came on..

So today he took it to the dealership to have it fixed.. They said it was the PCV valve.. So they replaced the PCV valve and the hose.. They charged my grandpa like $400 to this and guess what its still doing the same thing.. only the Check Engine light is off now..

So what else could it be?? he doesnt want to take it back to the dealership because they already him over once today..

 

Ok so I did a little research.. Im thinking it could be the IAC (Idle Air Control) valve?

Would this throw a code if it were bad or make the Check Engine Light come on???

Is there any way to test it? I dont want to make my grandpa spend any more money needed than he already has.. Im kinda upset about the price ford charged to change the PCV valve when it wasnt even the problem

 

Come on people... I Have to find out whats wrong with this truck it needs to be fixed tomorrow

 

it's possible. does the idle go up and down or does it just idle rough and low now? You might be looking for a vacuum leak if it idles up and down - maybe they didn't install the pcv value correctly

 

Well I sprayed starting fluid around all the hoses and didnt find any vacuum leaks... so i took the IAC of and cleaned it with some carb cleaner and put it back on... It idles alot better now but still drops a little every now and then but not as bad.. So were going to go buy a new one tomorrow and see what it does

 

I am having the same problem with my truck .... replacing the IAC fix the problem .?