About 4 months ago I started to get a bit of a shudder when lightly pressing the gas at about 40 mph. After researching the problem, I purchased 8 new coils Motorcraft DG511 and 8 new plugs Motorcraft SP-509 and installed. I was prepared to have to pull the two piece plugs, but I got lucky and didn't have them. I didn't read until later that they switched to a different design in late 2007 and mine was manufactured in 10/2007.

Shudder is still there, so I decide that I better just let the dealership try to find the problem. After about 2 hours they call to tell me nothing was wrong with the engine and they were sending it to be checked out by their transmission specialist where it then sat for 3 days. This being my family's primary vehicle, I wasn't interested in paying for a rental any longer and the dealership couldn't tell me when it would be looked at, so I picked it up and took it to a local repair shop. They check over the engine and find a broken plug which they replace, but the problem is still there. Now they want to charge me more money to "start taking things apart" to find the problem.

Before I agree to pay more money, I call a friend who has AutoEnginuity (also a member in these forums and who suggested I join and post) and we hop in and run some checks. No engine codes. No transmission codes. What it does show are some weird Lost Communication codes. I've also attached some pictures of them.

Transmission Control CAN: U0100, U0121, U0155
Vehicle Dynamics Module CAN: C1893, U0140, U0100, U0155
Anti-Lock Brake/Traction Control CAN: U0100, U0101, U0155
Airbag CAN: U1900
Audio Control Module MCAN: U2473
Instrument Cluster CAN: U0100, U0101, U0121, U0122, U0151

We wiped the codes and re-ran the tests and these sames codes showed up again. I'm not sure where to go from here. Did I install the wrong coils or plugs? Should I have used the SP-515? Would a transmission flush make a difference? Do I need to start tracing wires? Expedition has 126,000 miles on it. I've put almost 100,000 of those miles on it. No towing. I'm just not sure what to do next.

 

My 08 EL is doing the same thing. Accept it has become more than a little shudder. I took it to the dealership and they told me my full drive actuator was out and replaced it for the tune of $800 and that didn't fix it. They had several other ideas and wanted to charge me to try each one until it got fixed I opted to just take it home and drive it. But now it seems to be getting worse and my wife is afraid it's going to leave her stranded one day. If anyone has an answer I would appreciate it. Thank you for starting this thread Dreaming.

 

Motorcraft SP-509 are fine. They're the recommended plug and the one I used for my '11. Regarding the coils, I would have tested them before replacing them. Although many people treat them as a maintenance item, they aren't. A coil will either work or it won't. In any case, you would know if you used the wrong coil. The DG511 is straight whereas the DG508 has a slight bend in it. In any case, neither plugs nor coils would cause all of those communication errors. If you haven't had the transmission fluid/filter changed yet, I would do so - but it isn't likely to resolve this particular issue.

Now as to those communication errors, while they could be the product of a bad ground, wiring problem, etc. it's also entirely possible that they are the result of connecting that scanner. Was the scanner plugged in with the engine running or before? Clearly you have an issue if you have shuddering, but I would first try to determine if those codes are legitimate.

 

When is the shudder happening? And when is it most noticeable? Upon startup, while driving? Idling?

 

I definitely see your point, k9education, about just testing before replacing. After reading a bunch about a shudder issue being related to coils, I admit, I figured since I have 126k miles on it, might as well do them all. My mistake!

Now, to your question. I did have a parts chain scan it before taking it to my friend. No engine light, but I asked them if they would just to see if anything was stored. When the girl plugged in the scanner, the engine was running and the wrench came up on the dash. She then read the communication errors. That's when I drove directly to my friend with the AutoEnginuity goodies. I know that when the parts chain girl plugged in the scanner it did something because leaving the place, everything was messed up. Engine was running bad, it felt like I was trying to start off in 3rd gear.

When we plugged in at my buddy's initially, the engine was off. He started it and it ran noticeably better, so went ahead and read the codes. The communication errors are all that showed up. He then reset everything and let it run for a minute before we took it for a drive. He watched various things while I drove and duplicated the shudder, then we pulled over and he checked the codes with the engine running and they showed up again. We did not unplug between code reads.

rexster314, the shudder shows up once the engine is warmed up. It doesn't shudder on a cold engine. I can reliably duplicate it at 40 mph by lightly pressing on the gas to try and accelerate to 45. At around 60-65 and below 30 it doesn't shudder.

One interesting thing I just noticed the other day while I was trying to take a video of the shudder. When it shudders, the rpm moves about 2 notches then when it stops, they move back.

 

I assume you changed fuel filter and checked fuel pressure?

 

I believe my last oil change included a fuel filter change. It's due for an oil change. I was going to have them do a transmission flush. I can have them check the fuel pressure as well. Although, it's definitely not a dog. When I stomp on it, it goes.

 

Yeah, I guess it depends on if your tach shows RPM loss during the shudder. I would think if any one cylinder had an imbalance it would throw a cylinder misfire code.

 

I'm the buddy with the scanner.

Using AE with the ford enhanced bundle, we watched the cylinder balance and the motor is smooth at idle. While driving down the road, rpm isn't impacted by the studder. That is what throws you off. No misfires reported by the PCM, no changes in RPM.

As a diesel guy, I struggle with gas motors, but thanks to AE, I can find just about anything if I know where to look.

 

Update! Went in for an oil change this weekend and had a transmission flush done at the same time. The flush pretty much eliminated the shudder. Now it is just very slight.

It's looking like the shudder and communication errors are unrelated. I'm also a little shocked that this problem isn't triggering an engine light. On my '98 F150, I had a very slight 3rd gear slip that triggered it. Flashing OD light. Transmission flush fixed that problem.

I'm going to check the plugs this weekend. Make sure there aren't any cracks. Also going to start checking the wiring for any loose connections.

 

New member here. I have a 07 Exp EL. Developed that shudder at about 120K miles and kept getting progressively worse. Took it to the dealer - said I needed a new tranny at 5K plus the converter. Said whoa and started looking around the net, and found this is a common problem beginning around 45MPH until it gets above 55. The solution for me was a simple tranny flush and filter change with a Ford fluid additive. The shuddering you have left will gradually go away.

 

Yep. The shudder is completely gone now. Such a simple solution, but hard to diagnose.

 

That's ludicrous. How do you recommend a $5K+ repair without being absolutely 100% certain? This is a prime example of why I never take my vehicle to the dealer once the warranty is up. There are usually one or two knowledgeable, skilled techs in the shop and everyone else is just guessing.

 

Thank you to k9education....Took the advice of your posts regarding the supposed tranny shudder being a coil related miss....100% correct.

 

Thanks for the post. I bought my 2007 Expedition in 2014 with 78k miles.

Around 90k I noticed the shudder but it only happened once in a while and it took me some time to study it to narrow down when exactly it would happen. It's exactly as described by the original post. While driving 40 MPH with little throttle pressure, it shudders.

At about 110k I had the transmission fluid flushed along with the differentials and transfer case.

I'm not sure if it really got that much better after, but now at 146k miles, it happens a lot more often. There are no codes nor check engine light. I have trained myself to downshift to 3rd when it happens, then back to D after I get to 45 MPH.

Based on the successful flush story here for the exact same symptom, maybe I'll try getting the transmission fluid flushed again. It's an easy experiment. I'll report back if I notice a change for the better.


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