Hi everyone,
I have my 2006 5.4. Recently I had the motorcraft spark plugs installed as it was bucking going up hills. Problem went away with the new sps installed.

Now, and this happened once before the plugs were installed. The truck runs fine until I start slowing down. I get to a light and the engine starts shaking and it will stall out. One time, it was making what sounded like a grinding noise. I hit the gas a little and it goes away. I feel like the RPM is dropping too low?

Shop had it for a week, no codes, they drove it, said everything was fine, they couldn't find anything wrong with it and I picked it up yesterday and it was acting up again.

97,000 on it. I asked them about a vacuum leak, clogged fuel filter, etc they told me everything checked out ok.


Any pointers or tips you can offer to point me in the right direction would be very helpful. Thank you for your time.

 

Clean the MAF and throttle body and see what happens.

 

^^^ What he said ^^^ Your problem sounds just like the classic dirty MAF sensor and surrounding area.

- Jack

 

You're cam phasers may not be locking back into place at idle throwing the cam timing off. Summer temps and thin oil can cause this. If you're running Xw20 oil, try a 5w30 or heavier. the increased pressure at idle will lock the pins back into place.

 

Put a bottle of Gumout for high mileage engines in about a half tank of gas and run it through.