Vibration while stopped in gear

[Chad Kennedy]

When I am stopped at a red light while the ST is in gear i have a lot of vibration. If I put the truck in neutral it disappears and when I start down the road again it quits. Any idea wht this may be and how to get ride of it.



Thanks

 

[Todd Z]

What is the truck idling at?.. You could have a miss in the engine, bad wire or something..

We kinda need a little more info to try to diagnose...

Todd Z

 

[Chad Kennedy]

The ST idles at 1000-1100 RPM.

 

[Todd Z]

Sounds like a vacuum leak, Bad IAC, or clean the IAC motor. It should not idle that high,,

How are your filters??? When was it ( if it was) tuned up?

Todd Z

 

[Chad Kennedy]

I haven't checked the filters. I just bought it in October 2005 and of course the used car warranty has run out. I kind of assumed the dealership would of done a little tune on it.

 

[Michael Cacioppo]

1100 is too high an idle. As Todd Z said, it probably is an vacuum leak.

 

[LB]

Skillet.



I was actually talking to my mechanic yesterday morning about this. He said it is normal, but hardly noticed by many Ford owners. All Ford vehicles do this, just at different points. Ford tries to "set" this abnormality (the vibration) at a point in which most consumers wouldn't notice it. However, I noticed it in my Trac about 9 months ago, in which I have brought it to Ford 3 times for and they couldn't figure it out. Then just yesterday while having my battery checked, I asked him about it and he had an answer for me.



Hope this helps. But yes... it only happens in gear, not in park. It can be happening in gear, and once you shift to park it goes away (well, not really, it just becomes less sensitive). While you are in drive, you can turn your wheel slightly to the left or right and it vibrates more and in some spots not at all. However, put it in park and it will still do it, just slightly less and not as "hard" as when in drive.



LB

 

[LB]

Todd Z...



My Trac may also idle this high. How do I check for a "vacuum leak, Bad IAC, or clean the IAC motor". And should I have it tuned up?

 

[Todd Z]

Lb, How many miles on your ST? If over 30K your fuel filter and air filter should be changed. A tune up (plugs and wires) not needed till 100K, BUT i highly recommend doing it at 60K...



The IAC is not that hard to clean. IF it was bad the truck would not run. SO I say clean it..



Here is a link to a project I wrote on cleaning the IAC...



<a href="http://www.mysporttrac.com/mysporttrac/projects/CleaningIAC/CLEANING_IAC_MOTOR.htm">

HOW TO CLEAN THE IAC MOTOR

</a>



As far as checking for a vacuum leak, the most common is the vacuum elbow. You can look under the throttle body for the elbow. Here are 2 pics.



There is propane test that can be done, or by spraying carb cleaner around the engine while it is running, but I would check the elbow first...



Todd Z

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[Chad Kennedy]

I just went for a ride in the ST and i mad a mistake about the idle, it actually idles at 500-600 rpms. Still has the vibrations at stop lights.

 

[Chad Kennedy]

LB, your right on the money on the vibration, my ST does the same as yours.

 

[LB]

Todd Z, I am almost hitting 30K (within the next 400 miles actually) and tomorrow I'm due for an oil change so I'll add the fuel filter and air filter to the list. Any tips or tricks I need to know about changing those? I've never changed those myself before.



Skillet, Yup, glad to see someone else is in the same boat. I've been worried about this for several months now, and then just yesterday I resolve the issue with my mechanic and then find the same issue here?! Coincidence... ewww. Spooky eh, haha.



LB

 

[Todd Z]

Lb, the air is easy, the fuel is a PITA if you never changed a new ford one.. you need special tools also... May want let a shop or the dealer do it...

Todd Z

 

[Boodrodon Dykes]

I was actually going to aska bout this today. Mine idles at around 1 sometimes...and its a little ruff. I just noticed the past few days that when ive been in gear at a light, i can see it moving up and down about 1-2 milimeters. this kind of scares me. I have also had a few ruff starts where when i start it up, itll almost die a couple of times then its fine....(only happened twice). Is this the same thing? I also have had a check engine light on for about 4 months now, itll go off for week, couple days, or a month. Then it will come back for months, days or weeks. When its been on for a month or so, I have had it check many times, and the machines cant read anything. The ones at autozone wont even turn on when plugged in. I have done the battery trick many times, and it works for a day and thats it. I have cleaned my IAC also (month or 2 ago). Could it be the elbow, or soemthing serious?





Boodro

 

[Todd Z]

if the scan tool can not read when plugged in, you may have a blown fuse for the test port. Check ALL fuses, and then check the elbow, and then clean the IAC..



You may have something more serious...

But the scan tool should read the port, IF not there is something wrong

Todd Z

 

[LB]

Todd Z,



What specials tools are needed for the changing of the fuel filter? I'd prefer to do it myself, to save money for one, and two, so that I know how to do it. I don't like not knowing my truck.



LB

 

[Todd Z]

LB, It is called a Ford fuel line tool..... Get the metal one. the plastic ones STINK!!!

Todd Z