Need help. Erratic idle. About a month ago, when coming to a complete stop, the engine RPM's jumped to aprox. 1100 causing the truck to learch forward (almost into the back of the car ahead). This would happen occasionally. I replaced the IAC, MAS removed and cleaned the throttlebody, intake runner, EGR, PCV. This problem has not returned. The next problem has existed prior to the erratic idle and has both of the Ford Dealerships puzzled. They want me to drive the truck until something breaks. One of the dealers thinks the converter clutch is not releasing (even though the high rpm happens in PARK). Their are no error codes. When coming to a stop from average driving, the RPM seems very high (850-1100). This causes the truck to continue to pull for a few seconds, then the idle slows to normal (580-600) and all is well. If I put the trans in neutral while the truck is pulling at idle the RPM's jump to about 1100 for a few seconds. This happens more frequently after the engine temp is at normal and the outside temp is above 90. Have noticed when at idle (for 15-25 minutes) in park the engine idle creeps up to between 900-1000rpm's. It will continue to idle high until I drive for a few blocks, then the idle returns to normal. Generally the truck drives and shifts normally, gas mileage is still about 16 in town with air and 23 on the road with cruise. Can not find any vacuum leak, or air leak in the intake system. If I set the cruise control to 30 MPH the truck will not maintain a level speed, it increases and decreases speed to the point where the cruise turns itself off. I can not maintain a steady speed with the accelerator on level ground. If cruise is on and going down a hill the vehicle speed continues to increase to where I have to brake to keep from running over someone. Have had very little trouble with the truck, engine oil changes at 6K, trans flush at 20K. The truck has 62k and always starts and runs all day long. No hesitation, always has power when needed. This is a service vehicle at work and makes 8-10 service calls a day.
Any help work be greatly appreciated.

 

I am sure the converter clutch is not releasing. That truck should have a 4r100 transmissions with a triple plate clutch assembly.
I see the problem in them everyday the triple plate is a pos. If you want it fixed so you don't have to worry about it install an aftermarket converter that uses the luk design dual spring single plate lockup piston.

Alan

 

Thanks for the reply dirtydog,

But one small question, If it is the converter clutch, why will the idle increase when the truck is in park. I don't see the connection. The computer is given info from some sensor causing it to increase idle as if a load is being put on the engine( A/C, windows, etc). I can idle the truck for 15-20 mintes in park or neutral and when the outside temp is above 90 degrees the idle will increase to 900-1000 rpm's. Do not understand why the clutch would ingage when out of gear?? If you have read the previous post, with cruise control on and set at 60 mph, the truck will increase rpm's while coasting downhill to the point I have to brake to keep from running over someone.

Any other ideas are appreciated

 

The clutch engages because it is a mechanical issue inside the torque converter. The idle goes up and down because the computer senses the idle dropping too low and tries to increase the idle speed.
I would take it to the dealer and tell them it keeps stalling on you when it gets hot or some crap like that.
A friend of mine is having problems with his F150 as well and the dealer he took it to was doing the same thing to him. He took it to another dealer and it got fixed immediately. I suggest researching your local dealers and find out which ones have the better service department. Take it to them. I can't explain the cruise control problem but my ranger did the same thing for a long time. You may want to check for leaks in the vacumm lines going to the cruise. If there are any the newer cruise controls aren't vacumm operated anymore.
Alan

 

wait i have a 01 Screw but with a 4r70wsomething tranny, not the 4r100 you mentioned, is there a way to verify? my trans code is U? not to get offtopic which i have but this is the first auto tranny i owned in 11yrs so ALL the info i can gather is helpfull....

 

I am not sure how to verify the transmission. I can tell the difference by looking. This subject comes up alot. I'm sure a search will find your answer.
Alan

 

Trans code "U" is the 4R70W tranny.

 

I am glad and sad to hear that the problem isn't just on my truck. I was wondering if you have got this fixed. It seems that you have tried mulitple methods in the past to fix this problem, but I don't see where you have tried to replace the torque convertor. What is the cost of replacing the convertor? Why doesn't Ford take responsibility of this seemingly common problem? Is this a problem that needs to be fixed promptly?

 

I have seen this problem on alot of the triple plate ford converters. The deal is that the front cover is not hard enough to hold the clutch plates. Not all of them do this but alot of them do. I have seen the problem on powerstrokes as low as 30k miles.
Generally they last until they are out of warranty so ford doesn't really care. Cost of replacing the converter will vary depending on where you get the converter and how much it costs to have it installed.
I found one on bulkpart.com for 262.50 it says it is a single plate but it doesn't say if it has single or dual springs.
Factory tech sells a very nice unit for $950
Alan

 

I went to Auto Zone today and they don't even have the 2001 Torque Convertor. They do have a 2000 version(Approx. $209). Are they the same? How hard is it to change. I am a novist at best. How good is Cottman Transmission versus the Ford Dealership?

 

They are the same when you are dealing with aftermarket stock replacement converters. Might want to ask what type of lockup it has but I doubt autozone will know. How hard it is to change will mostly depend on you and the tools available.
Alan

 

I have taken the truck to Cottman's Transmission shop and they diagnosed as such; no problems with transmission, one code of P1127 (Oxygen Sensor code). What now? Does this make sense?

 

Yes O2 sensors can cause Idle problems because they screw up the fuel mixture.
Alan

 

Why would the sensor only screw up when it is hot and in gear??

By the Way, Thanks a million for all of the advice.

 

The computer uses base settings to control fuel mixture while the engine is cold. It then uses O2 sensor readings once the engine is warm for more precise control. It only does it while in gear because there is no load when settin in park or neutral.
Glad you figured it out
Alan