vacuum leak & oil in throttle body
 

I havent worked on the EX in a few weeks and the pinging is still there. I noticed it has been getting slightly worse and yesterday it was at its worse.

my symptoms:
stumbles slightly at a stop
pinging up a hill and flat surface but not as bad
poor gas mileage

Well now its got a loud vacuum sound. Sounds like it could be coming from the throttle body area? Could it be the IAC? Also when we looked at the throttle body it had oil in it, could that be a failing PCV valve? I am going to swing by autozone this morning then go to my Mom's Ford dealer and get a tech friend to listen to it. I am just scared that this thing is dropping dead on me.

Any ideas???

Usually the V10 is rock solid. I wouldn't worry about it dropping dead. However you do have an issue.

I would replace the PCV and the hose that goes with it.

I would also pull the throttle body and clean it. It's quite easy to do with a can of carb cleaner. This will give you an opportunity to inspect all the associated hoses and connections for problems.

Pcv valve is going in right now at my husbands honda dealer the ford didn't have the hose so I ordered it the throttle body was cleaned 2 weeks ago. I will post more news shortly Oh and no codes at Ford figures

After you do what Ken suggested if you still have a vacuum leak, a can of ether can be used to locate the vacuum leak. Spray small bursts of it around on the running motor where you think the leak may be. As soon as the ether finds the leak it will get sucked in and the motor will rev up. You found your leak.

Do not spray lots on there at a time since this stuff is still flammable. Small squirts here and there will help isolate the location of the leak.

Thanks neal we will do tha next this thig is frustrating. Forgot to mention when doing the plugs we noticed old rat dropping so who knows what type of damage we could be dealing with.

OK PCV is in and the shop foreman at honda found that the IAC is hissing!!! I was right and the bonehead at Ford was wrong!!! So I have the new IAC but no one had the gasket so I will do it tomorrow. I feel a ton better, and I am hoping that the X will be running like new tomorrow!

You can also just get a roll of gasket material and make a new gasket if you have to. I had to do that for the IAC on my '94 F-150 a couple of months ago. Nobody had them in stock.