Truck has 48,000 miles, when I start it and the engine settles down to about 550-600 rpm's the truck will lightly vibrate and shake. I notice it in park and while it is in drive sitting at a red light.

Every once and a while when I start it, it won't turn over right away, but when it does crank it will start at real low rpm's (like it could stall) then it will recover and jump up to above 550 rpm's.

The truck runs great except for that rough idle. Does anyone know of a possible problem. I've had the Ford dealer try to diagnose the problem but they found nothing, also the check engine light has never come on.

Thanks!

 

My 5.4 did that same thing for about 5,000 miles and then i found out i had a blown head gasket dont freak though could be something completely different but when i did do the head gaskets.. its stopped. Check vaccume lines, bad gas... try running some 93 in it see what that does, check the codes anyway something may be there if the "service engine soon" light isnt on. My truck had a blown head gasket and took it around 10 days for the cylinder 4 misfire to show. 10 days from the first over heat that is... Edge saved my A$$. but at 48k i cant see a head gasket, mine had over twice that. good luck

 

I had the codes checked even though the check engine light wasn't on but nothing showed up. I'm just going to leave it alone instead of dumping money into it trying to solve the problem since it could be a number of things that could cause a rough idle. It sounds like others are having these issues with Ford engines as well from what I've been reading.

Thanks for the info you provided!

 

Clean the throttle body and IAC.

 

Bingo, clean the MAF sensor too while your at it with MAF sensor cleaner. The truck will always have a small vibrate here and there, no worries.

 

That's what I was going to say also... Idle Air Control

 

Thanks for all the advice and information!