Rough idle when cold fix

[wrightyonline]

Probably already been covered but thought i would post this after a day under the bonnet !

i had the problem of my truck idleing between 500 and 2000 rpm ! when cold
sometimes dropping so low it would almost stall, so today i decided to try and resolve this having read a few posts on here,
i started by taking off the engine cover and removing the idle air control valve
(IAC) and checking to see if it was clogged, it wasn't so back to square 1, scratched my head abit and thought a little

so i decided to take the whole air intake system off, after removing the air filter and box, the air flow meter,air pipes and main air intake tube,and throttle body !, i noticed something odd, the whole of the system was covered in what i can only describe as wet brake dust :thumbdwn: i was really puzzled by this as ive owned the truck nearly two years and the problem only started a few weeks ago, and ive never seen this sludge before when i changed the air filter, anyway heres what i did,

I took all the parts i'd removed and covered them in engine degreaser, then scrubed and cleaned them thuroughly before washing them all off with a jet wash, once they had dried off completly (several hours that i painstakingly lounged around in the sunshine) i reffited them all ensuring as i did so all parts were dry (this is important !)
the result was that when i started up my truck it sounded awfull and belched out lots of white smoke and water i was about to cry when the revs rocketed and a big cloud off grey smoke shot out of the exhaust and hey presto all was well again

have tried the car two or three times again today and can say that it starts and idles fine, it runs smoother and the throttle response is sooo much better , what a result !

not sure if this will help others but it has certainly made a huge difference to my explorer, so might be worth a try if you have the same issue and iac valve isnt your problem

 

[Big-E]

Thanks for posting this.. Now you gave me something else to try for my cold start issue!

I will let you now.


Eric

 

[joe doe]

thats not the fix .....chime back in when the problem arises again and i will help you .

 

[koda2000]

c'mom joe doe! If you know something about how to fix this apparently common problem, spit it out. Do you want us to beg?

 

[joe doe]

well i wanted to see if his problem returned ,which i am sure it will .
the common cold idle issue is related to the upper intake orings which shrink with age and allow air to pass by them when cold ,resulting in a bad cold idle that clears up when the engine warms up .
when the engine warms up these orings swell and start sealing again and idle will return to normal .
sometimes this issue will throw a lean code as well once it gets bad enough .
do a forum search for lean codes or upper intake orings and read up .

gotta run ,catch ya

 

[koda2000]

re: intake o-rings fix. Okay, this fix sounds reasonable and I plan to replace my upper and lower o-rings soon hoping this solves this annoying problem. What I don't get is how the o-rings can seal after the engine has run for only 5 seconds. On a restart it's fine. Surely no measureable heat has built up in that short a period of run-time. Maybe it's at least partially vacuum related...

 

[joe doe]

well this isnt your thread and i dont know your symptoms or what you have experienced .if your problem only persists for a few seconds and your not getting any codes i would surely wait until the problem is more prominent .

when it gets bad enough to throw a lean code then its time .my truck had well over 100k on it when i done mine .