02 Taurus ses

My taurus has a very rough idle, is worse when it comes to a stop and when the air cond. is on. Also the check engine light stays on. Here is what the mechanics have done so far.
1. Replaced Ignition coil pack
2. Replace the plug wires
3. Replaced plugs twice
4. Replaced the air filter
5. 3 new gas caps
6. Replaced down spout to gas tank
7. Replaced o rings
8. 1 bottle of fuel conditioner
9. 2 bottles of injector lube
10. flushed injectors
11. Tank of premium gas
Three different ford dealerships have put it on their monitor for the miss in idle, nothing shows up on the monitor, even though the car is shaking from the rough idle. I have paid for all this work to be done and no one has fixed the problem. What do I have replaced next.

What code are you getting from the check engine light?

Take it to Auto Zone and report back here with a code number

Mike
:smokin:

I know that I'm starting to sound like a broken record here. If you taurus has more than 30K on it with the origional fuel filter in it, replace it. It almost sounds like your fuel rail isn't getting enough fuel to it. Try replacing it anyway since you may have gotten a couple of tanks of dirty fuel and have a clog in your fuel system. If it's still there afterward see if you get good pressure at the fuel rail. Shorod might have a few ideas that I haven't thought of.

Sorry, Had to find print out from autozone, had the car there in June. Code was P0456. mechanics said they could not find leak.

Idle Air Control Valve - Sits on top of the intake air tube, change it in five minutes, Costs $50.00

Powertrain code P0456 indicates "EVAP Control System Leak Detected (Very Small Leak)" according to the factory service manual. Also according to the manual, the typical causes are:

Very small holes or cuts in fuel vapor hoses/tubes.
Loose fuel vapor hose/tube connections to EVAP system components.
After-market EVAP hardware (such as fuel filler cap) non-conforming to required specifications
Small holes or cuts in fuel vapor hoses/tubes
Canister vent solenoid stays partially open on closed command
Damaged, cross-threaded or loosely installed fuel filler cap
Loose fuel vapor hose/tube connections to EVAP system components
EVAP system component seals leaking (EVAP canister purge valve, fuel tank pressure sensor, canister vent solenoid, fuel vapor control valve tube assembly or fuel vapor vent valve assembly)-Rod

Found the bill on that one. To install the Idle air control motor was $45 for the IAC motor the cost was $61.55. At that time they also installed a Plentim Gasket, total cost for that was $81.99. I guess when they see a female bringing a car in for repairs, dollar signs flash in their eyes.

Sounds like it is time to take it somewhere other then a dealer. They sound like pretty good parts swappers but aren't any good at diagnosing anything. I won't tell you what to replace because everything already has been. What I will say is that EVAP codes very rarely cause any drivability problems and that code may have nothing to do with the problems you are having. I would be looking at fuel trim and the idle controls but you need a scan tool to do those things.

First thing I would check is the pcv valve. That elbow from the
pcv valve gets very hot and comes apart...Happened twice with
my 2000 ....That would cause the symptoms but acturally you
should get a code fir theat...just a thought. Pcv is located at
the top and end of engine , passenger side.

QUOTE=nhelp]My taurus has a very rough idle, is worse when it comes to a stop and when the air cond. is on. Also the check engine light stays on. Here is what the mechanics have done so far.
1. Replaced Ignition coil pack
2. Replace the plug wires
3. Replaced plugs twice
4. Replaced the air filter
5. 3 new gas caps
6. Replaced down spout to gas tank
7. Replaced o rings
8. 1 bottle of fuel conditioner
9. 2 bottles of injector lube
10. flushed injectors
11. Tank of premium gas
Three different ford dealerships have put it on their monitor for the miss in idle, nothing shows up on the monitor, even though the car is shaking from the rough idle. I have paid for all this work to be done and no one has fixed the problem. What do I have replaced next.[/QUOTE]

The dealer should have a PDS Diagnostic system that can pinpoint the cylinder or cylinders that have misfired or are misfiring. If you know anyone that has a scanner that can read what is called mode $06, you can pinpoint which cylinder has the miss. The P0456 probably will not cause the engine miss. More than likely that is an "o" ring seal in one of the connections in the EVAP system.