Mondeo Over Reving

[mickyboycfc123]

Hi all soz if this question has come up before ,i have a mk3 mondeo 04 petrol ,the past week everytime i stop my revs go from 1000 to over 2000 then back to 1000 ,,,,,,,now i took the car to the local garage ,he ran a diognostic and the result was idle controll valve wich i replaced and cleaned what carbon was there ,,but the problem is still there i have checked and double checked for cracked or broken hoses ,all looks ok ,i noticed the accelerator cable was very slack ,not sure if its that thats the problem ,,,i have also noticed that when i rev the engine just before the revs drop there is a shuddering from the exhaust ,,any help much appreaciated

[troy45]

Is the accelerator cable moving freely? Should be able to test that without the engine running, with a suitable assistant to operate the pedal while you take a look under the bonnet.

While not the only potential cause, if the cable is sticking then you'll have a delay between lifting off and the throttle actually releasing. Definitely needs checking out as the last thing you want is the fault turning into a broken cable or throttle stuck open.

[mickyboycfc123]

Is the accelerator cable moving freely? Should be able to test that without the engine running, with a suitable assistant to operate the pedal while you take a look under the bonnet.

While not the only potential cause, if the cable is sticking then you'll have a delay between lifting off and the throttle actually releasing. Definitely needs checking out as the last thing you want is the fault turning into a broken cable or throttle stuck open.

thanks for the quick reply troy45 theres about 2 inches slack on the peddal side ,,,,,,when i move the accelerator from the engine bay you can feel there is some slackon the cable ,do you rekon that could be the problem

[mickyboycfc123]

ok its got me beat ,still no further on after spending 2 days on it myself and had 2 diagnostic in 2 diff garages ,,,changed the idle control valve (no joy) could it be the coil pack n if so is there a way to test it ?

[troy45]

Diagnostic machine won't bring up a sticky throttle cable imho, think you'll still need to have a look at how freely the cable moves. If there's slack on the pedal side is the throttle body being held open at the same time? if you disconnect cable from the TB then see how freely it all moves - can help if someone holds the end of the cable while you operate the pedal to put some tension on it all and stop the cable outer disengaging instead.

[mickyboycfc123]

you could be on to something there mate ill try that tomrorow ..i have also ordered a throttle body sensor hopefully it comes tomoz and ill try that ,,,,,,to be honest mate im trying the elimination game and hopefully the cost doesnt get any higher ,its a old car but a good one ..and im of to scarbourgh in july hoping to use the mondeo to get me n the family there thanks for the reply maty

[pragmatix]

Got to check that cable

[mickyboycfc123]

the cable definetly has lots of slack ,,moving the cable from the engine bay up and down i can hear the accelerator pedal moving taking up the slack and releasing it ,,its probabley got at least 1 to 1n half inches of slackness,,,,,,,also i dont know if this is of any relevence but its only when the car is heated up does the over revs start

[pragmatix]

Heat may well make the cable stick. It's a cheap fix if that is the cause

[mickyboycfc123]

UPDATE ,,,,, cleaned out throttle body ,,,,changed throttle body sensor ,,,changed idle control sensor,,,,also changed accelerator cable ,,,,still the same ,,,,,my mate notices a crack on a pipe behind the manifold ,i tried tried to get a decent pic without taking manifold of ,,there seems to be 2 pipes and one looks cracked i have attached a pic for you to see its not the best as the manifold is still on ,,,so thats a job for my daughters boyfriend to strip of manifold lol,,,so i would like to thank all you guys for your time ,and if ive helped any one out with the things i have done to the car and the end result so cheerz all

http://www.freeuploadsite.com/do.php?img=69000