Rough cold idle

[hijinks]

For the first 20 minutes or so driving, whenever I come to a stop I get a rough idle that will slightly shake the stearing wheel. It will phase in and out. It doesn't happen when I start to move. Anyone have any advise to where I should start looking?

Thanks
Mike

 

[tbomb]

i get that too, a little bit, but mine wont do it for 20 min. ill get a little vibration at idle (i.e.: stop signs, sitting still, etc.) until the truck warms up, usually just a few minutes; i think this is probably normal with the sohc. is yours the ohv or sohc?

 

[hijinks]

its a sohc. I'm not to concerned about it since it does run fine when moving.

 

[tbomb]

well, the sohc is known to be a "vibratey" engine (thats actually the term a ford technician used.) if you have a kkm or certain other mods, it could affect the "vibratey-ness" of the truck, too. i dont think its anything to lose sleep over either, but i dont know that theres much we can do to alleviate it, either.

 

[Robert]

Be sure that it is not your lower intake manifold o-rings leaking air. It can cause a rough idle while the engine is cold. Ford will replace them free under ONP 00M12 if you are under 72K miles.

 

[tbomb]

robert, i already had my lower intake manifold o rings taken care of via that recall, but could they need to be redone again?...is that possible?

 

[Robert]

It is if they messed up on the installation. Per the original TSB, the o-rings may be folded over either during vehicle assembly or during service that required the removal of the lower intake manifold. If one isn't in the groove all the way when the manifold is put back on, it will have a leak. If yours were replaced as part of the ONP, then they should have used the revised o-rings and should have known how to put them in. Unfortunately not all Ford service centers are as diligent in their training as they should be. There are some troubleshooting steps Ford can take to determine if your o-rings are leaking. I don't know if they will charge you if the problem is not related to the o-rings though. Somehow I think they would. The troubleshooting steps involve spraying propane in around the lower intake manifold with the engine running while monitoring the short-term fuel trims with an OBD-II scanner. That was the procedure used to track down my leaking o-rings.

 

[tbomb]

ok, thanks. my truck has to go back to ford next friday because they forgot to fix some sort of leaking seal in the wheel bearing (or something like that.) ill be sure to mention this to them, but i think my truck's idling well, i just get the vibration sometimes.