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Ask A. Penland Your Own Question
A. Penland
A. Penland, Ford Senior Master Technician, ASE
Category: Ford
Satisfied Customers: 6212
Experience:  ASE Master Certified, ASE Advanced Gasoline Engine Performance
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Having an issue with my f150

Customer Question

having an issue with my f150
Submitted: 1 year ago.
Category: Ford
Expert:  A. Penland replied 1 year ago.

What is the issue you are having?

Customer: replied 1 year ago.
On the highway the truck seems to stumble. I had a ford dealer replace the plugs and I replaced all of the COPs still having the issue. Just bought the car used and of course the dealer I bought it from blames that work
Expert:  A. Penland replied 1 year ago.

What engine does the 2005 have?
4.2L

4.6L

5.4L

Customer: replied 1 year ago.
5.4
Expert:  A. Penland replied 1 year ago.

Does it stumble on acceleration or at a steady cruise?
Where did you get the coils?

Customer: replied 1 year ago.
It stumbles if I give it a little gas so as not to cause it to downshift. If it downshifts it does do it. I got the COPS at auto zone. I tested them with a waekon cop tester and they were all firing after I replaced them
Expert:  A. Penland replied 1 year ago.

Does it do it if you accelerate around 30 to 40 mph or does it do it from a stop and then accelerate?

Customer: replied 1 year ago.
It does it on the highway generally going up a slight hill. Acceleration seems fine. Not as zippy as our BMW but it gets moving
Expert:  A. Penland replied 1 year ago.

Ok, I have seen this in a few F150s. The problem is in the transmission, caused by the torque converter and the TCC solenoid for the torque converter. It is not caused by the engine. The problem is that the TCC solenoid it trying to apply the torque converter and it is slipping, or shuddering when you accelerate under load, especially uphill. You will need to find a repair shop that has a scan tool that can monitor the TCC Solenoid Actual PID and the TCC Solenoid Desired PID that the PCM (Engine Computer) monitors to apply and release the torque converter.

Customer: replied 1 year ago.
the truck has 101000 mile on it is it possible that it is in need of a transmission oil change? I have heard this can be a cause? Is the scan tool you mentioned super specialized or do most shops have one? I am assuming it needs to be done under the conditions that cause the studded/stumble.. What would be the difference between the actual and desired that would indicate a problem and is the problem generally the TCC solenoid, the PCM or the torque converter?
Expert:  A. Penland replied 1 year ago.

Actual is what is happening at that moment and desired is what the PCM wants to see. Most shops should have one. And yes, they will need to drive it with the scan tool connected to actually see it. You can try the transmission fluid exchange. It may fix it, but it is a 30% chance, especially with 101,000 miles.

Customer: replied 1 year ago.
is it likely the TCC or the torque converter?
Expert:  A. Penland replied 1 year ago.

Yes. But I would like to see it verified instead of a shop throwing parts at it.

Customer: replied 1 year ago.
Me too. So it is not likely to be the PCM
Expert:  A. Penland replied 1 year ago.

No, I doubt it.

Customer: replied 1 year ago.
OK that confirms my suspicion. I told the dealer I thought it may be the TC and that is when he started blaming the plugs that the ford dealer replaced...
Expert:  A. Penland replied 1 year ago.

I have heard that about other dealerships in my area also. They blame the simple things instead of properly diagnosing the problem. Way too many parts changers in the auto repair business now days.

Customer: replied 1 year ago.
If it is the TC what would I expect they quote for the repair? Of course the selling dealer would be responsible for the work
Expert:  A. Penland replied 1 year ago.

Is it a 4x4 or*****

Customer: replied 1 year ago.
its a 4X4.
Expert:  A. Penland replied 1 year ago.

The torque converter and the TCC solenoid are about 7 hours labor. Not too sure on the price of the parts. Probably about $600 in parts. But that is a guess right now.

Customer: replied 1 year ago.
OK Thanks You have been most helpful. Have heat rest of your night. Will you send me a transcript of the conversation
Expert:  A. Penland replied 1 year ago.

You can print it out. I cannot send a transcript.

Customer: replied 1 year ago.
OK thanks have a good night
Expert:  A. Penland replied 1 year ago.

Your very welcome. Good night.

Expert:  A. Penland replied 1 year ago.

Please let me know if you need any more help.