Ford Expedition 2008 Shudder problem

Friends,

I bought ford expedition 2008 King Ranch with 147000 miles on it. Before purchasing i did computer test (by qualified technician) and mechanical inspection. also the test drive. Everything went fine. I used about 4 months. As summer started ( i live in saudi arabia) i started feeling shudder at a speed of 35-50 miles. it does not appear in first 60 km of drive. it appear after wards. it is something related with temperature. i got changed all spark plugs from the workshop. But issue not resolved. i did computer testing again and again, computer showing everything working fine (transmission module= no fault, this is computer checking result). i did some online surfing, some people say it is torque converter issue. I dont want to open the subject of transmission due to high mileage. i dont know, by fixing transmission issue car may end up in scrape.

Can anybody help.

When you changed plugs did you also change Ignition Coils?

When technicain remove the plugs, plugs were in very good condition ( previous owner installed just 50,000 km before), i still insisted the technician to change all plugs. Technicain confirmed me that all coils are in good condition and no need to change.

transmssion is shifitng smooth if i press the gas pedal strongly. if i drive between 35 to 50 miles, shudder is noticeable. important thing is it occurs when vehicle fluids get warm/ hot.

This weekend i will change transmission fluid and filter to see if this can help.

I was having the same issues as you did on my 2001 with 5.4 liter, I changed the plugs and the problem persisted.

How did the mechanic check the coils? By visual inspection all coils usually look the same, the only real way to tell is to check their resistance with an ohm meter to see if they are operating within oem range, unless the coil fails completely you will NOT get a check engine light for them, so one or more coils could be on their way out.

I changed all 8 coils and it was like a new truck, even though I did the spark plugs twice in 4 months, it was the coils that made the difference.

If the mechanic was doing the plugs you should have just bought the coils because he had to remove the original coils to change your plugs it would be best to put in new coils at the same time to save on the labor cost.

Also with 174xxx miles that is about the regular service life for the OEM coils, so it could very well be a factor. either way it definitely wouldn't hurt to change them, the increase in fuel economy and power is noticeable.

Best of luck

Thanks for guidance.

Mechanic did the visual inspection and said all coils are ok. i will go for changing all coils to see if it can help.
Actually i am still doubtful this problem is related to coils are transmission issue as it happens when gear changes from 3 to 4 probably. This is my first ford vehicle and unaware of its problems/ solutions etc.

from internet surfing, people solved this problem in 4 ways;

1. Changing spark plugs
2. Changing spark plugs and coils
3. Changing transmission oil and filter
4. Replacing torque coverter with new one
5. Re building the transmission

I am following the same path but will not go re-building the transmission.

This weekend i am changing tranmission oil and filter, if it helps, ok, if not, my next step is to change all coils ( i remember, when technician did the computer test first time, he showed me some graphs on the computer screen indicating that all coils are working fine, God knows! )

Let us know how you make out!

yesterday i took my car for transmission oil and filter change. technican asked me the problem and did test drive. he said shudder is due to bad torque converter.
he replaced the torque converter with new one, transmission oil and filter change. result is, there is no shudder whatsoever at any speed, no whirlling sound from engine (which was a constant source of grief for me). my expedition is entirely a different vehicle now.
i love my expedition.

thanks internet.

it cost me 1000 dollar (torque converter (motorcraft) = 750 dollar, labor= 250 dollar)