Vehicle surging with shudder/maybe torque converter clutch?

[Bill MacLeod]

I seriously thought about getting the transmission pan dropped again. From what I remember reading was that not even half the transmission fluid is actually in the pan/filter. I think more than half is tied up in the transmission and torque converter?

The capacity of the trans is 11 quarts, last time I changed mine it required over 7 quarts to fill. There is a fair amount of fluid above the filter, but I did allow it to drain for about 2 days.

 

[PotatoExplorer]

The capacity of the trans is 11 quarts, last time I changed mine it required over 7 quarts to fill. There is a fair amount of fluid above the filter, but I did allow it to drain for about 2 days.

Ah ok, thank you for clarifying that Bill MacLeod. So over half of the transmission fluid is in fact in the pan/filter. I suppose it still wouldn't hurt to do it again to ensure it's more clean than dirty.

For what it's worth, mine did this same thing a few years ago. Replaced the fuel filter and wala, problem gone.

Yoster... the most basic and obvious things can be overlooked and I'm not sure if it has even been replaced in the 120k miles prior to me owning it! I'll have to tack this on to my list of things to try next, thanks!!

 

[Bill MacLeod]

You didn't mention which plug had rust on the hex nut. If it was # 4 or 8, then good chance that water drips down for the hood seal clips. I put a light coat of dielectric grease on the coil boots and service the plugs once a year. Never had water get in but did have a misfire with champion one piece plugs. (junk) Also made a water deflector from some scrap aluminum.
Try swapping some coils (1 and 4 , 5 and 8) and lube with silicone grease.

 

[PotatoExplorer]

The one cylinder that made sense for being all rusted out was #4, but the weird one was that #7 was also like this, instead of #8. Very weird. After changing the plugs and then driving through a rain storm, I checked the rain hood shield thinger for drips and I noticed nothing dripping and no water on top of the engine. So that also had me puzzled as well... When it finally warms up enough for me to hand wash, I'm going to get at the rain shield from all different angles with the hose to see if I can get water down into the engine bay.

If I swap the coils around and still use a faulty coil on another plug, wont the problem still persist? The issue seems to only be when the transmission shifts into 3rd or 4th gear and when I'm cruising at a steady speed at very low RPMs, but the RPM surge doesn't happen at all in the lower gears in city cruising speed, at idle, in park, or at highway cruising speeds in the higher gears.

Makes me wonder too if it is a clogged/dirty fuel filter problem, wouldn't this happen especially at idle and throughout all gears??

 

[tripplec]

I would say no if its the fuel filter. A lot more fuel to handle at higher speed/load and if that design has an integral pressure regulator then it adds to it as a culprit.

 

[PotatoExplorer]

For what it's worth, mine did this same thing a few years ago. Replaced the fuel filter and wala, problem gone.

YOSTER, DUDEEEEEEEE!!!

I think we have a winner. The temps here in PA dropped back down to winter mode from the nice 70 degree temps of last week, but I decided to get out there and knock out the fuel filter replacement - you know what they say, crap my denim. I've listed a walk-through on how to change the fuel filter down below. Here's what I found when I tapped out the fuel filter. Actually, tapping it out from the outlet end resulted in some lightly tinged brown fluid, but tapping it from the inlet end resulted in this dark black fluid.

After test driving it 5-10 miles, I was finding it extremely difficult to reproduce the problem. Actually when the transmission would bog down the PCM immediately threw the transmission into a higher RPM instead of hunting. I plan on taking it out on another test drive within the next day or two. Thank you Yoster and Tripplec. I'll report in a few more days to tell you the progress, but I think this solved the issue!

FOR ANYONE WHO STUMBLES UPON THIS IN THE FUTURE -
Here's a basic walk-through to change a 2008 Ford Explorer fuel filter:
I drove the Explorer up on some ramps to give me just a little more room to work under there. The fuel filter is located in front of the fuel tank, and towards the back end of the engine, and in-between either side of the boxed frame of the truck (more towards the passenger side). The filter is tucked away behind a metal shield that's held together by 3 - 13mm bolts. Behind this metal shield is another black shield held together by 2 (I think they were 10mm?) nuts (lol, 2 nuts). This exposes the fuel filter - red clip indicates inlet end, green clip indicates outlet end of the filter. Now locate the fuel pump relay fuse in the engine bay (In my Explorer I think it was fuse #49) and remove it to cut off the fuel pressure to the system. Try to start the engine. In my case the engine wouldn't turn over, so I knew the fuel pressure was cut off. Now go back to the fuel filter - green clip just pushes through the black plastic bracket to allow the outlet end to slide out from the fuel filter. The red clip is a stupid design in my opinion - you need to pry the one section of the red clip up to allow the red clip to push through the black plastic bracket on the inlet side. This allows the inlet side to pull off of the fuel filter. Now you should have gas pouring all over you so I hope you have crappy clothes on. I tried to position an empty oil pan to catch the excess gas, which did come in handy. In the windy cold temps, this was a wonderful feeling, especially when you're on a bare dirt floor in just jeans and a t-shirt. Replace with an identical fuel filter (I went with Motorcraft) and make sure the filter is facing the correct direction. Replace the red and green clips, replace the black shield with the 2 nuts (lol), and replace the other metal shield with the 3 - 13mm bolts. Go back and replace the fuel pump relay fuse. Open the passenger door and locate/press the fuel pump reset button. Place key into the ignition, BUT DON'T START THE ENGINE. Turn the key to the accessories position for a few seconds and turn the key back off. Do this a total of 3-4 times to build up pressure in the system. You now should be able to fire her up - congrats, you changed the fuel filter in your Explorer!

 

[PotatoExplorer]

OMG... and it's back. W-T-F!!

Test drove it some more tonight and got it up into the bog down zone (35-45mph). It just kept cycling through the RPM surge over and over. Maybe the PCM has to take time to relearn???? Aghh, I'm at my wits end on this. I think I may take a trip to see the friendly people over at Carmax...

 

[Bill MacLeod]

Damn, thought you had it solved and fuel starvation was the problem.
When you changed plugs and noticed the corrosion on #4 & &7 plug hex nuts, did you remove the coil boots from those 2 cylinders and check for corrosion on the long spring? If not, shouldn't take long to R&R.
There may be codes stored in memory even though you don't have a CEL.

 

[PotatoExplorer]

Yeah, I thought I had it too

Weirdly enough, when I pulled the coils, the lower boot portion kept pulling off, exposing the springs. I didn't notice any corrosion on any of them, but I can certainly take another look.

I was searching around and stumbled upon this thread -
http://www.explorerforum.com/forums...etting-the-pcm-after-repairs-are-made.396533/

I wonder if it's as simple as this???

 

[tripplec]

Makes you also wonder if you should change your source of gasoline? Don't know what you use. I stick to name brands and Tier one stations whenever I can.

 

[PotatoExplorer]

Yeah, I only try to only fuel up at Gulf stations. I use to only fuel up at BP when I had my Mercury Sable, but since that whole BP fiasco, all of them got drove out of town. Not sure what the previous owners of this Explorer used though. Unfortunately, I had to fill up at a ****ty Sheets station (if you guys know what that is) this last time since I was out in the middle of no where near E.

It seemed like the original factory filter though since the red clip on the inlet tube didn't look to have ever been removed. Could have been worse after 120k miles?

 

[tripplec]

You have a lot of Tier One list in the US. Exxon, Mobile etc names I would trust. Anyway I also stay away from ancient setup looking like they been around for a 100 years or so. I never pull into a station that is being filled with a tanker especially in Winter. Its a recipe for a disaster IMO. If there is water at the bottom of the tank (all tanks have some) and you suck it in and it freezes you are screwed. Unless you know what to do. Also creates other problems on modern engines. I have told my son and some friends who also understand why. Its best to avoid them when the tanker is there topping up the tanks. In time the water will settle again.

 

[PotatoExplorer]

Actually I never looked it up, but I can't find any info on Gulf gas... it would appear that it is not even a top tier gasoline.

The problem with my area is that I'd have to drive over 30 minutes to go to the nearest top tier station. In Carlisle, PA, they all seem to have succumbed to cheap-o mart gas stations and chains like Sheets, Speedway and Turkey Hills. There use to be a Mobil/Exxon and 2 different BPs right in town. Now there's none. The closest Mobil is over an hour away, and the closest Exxon or Shell is 30 minutes! There are 2 new Sunoco stations near me. That's what my Dad use to always use... hmmm.

 

[tripplec]

Hmm yeah. Well a switch to Sunoco maybe worthy. I checked and don't see it listed either.

Given the situation if you are passing by Shell or Mobile etc on the way home. Top up now and then there. But staying away from the ****ty stations makes sense. LOL

http://www.toptiergas.com/licensedbrands/
http://www.autoguide.com/auto-news/2012/12/which-gas-stations-sell-the-best-quality-gasoline.html

 

[Bill MacLeod]

DON'T disconnect the battery to reset the PCM just yet, unless you have checked for stored codes.

Summary of your issues.

Post #34 - symptoms are surging and converter shudder/rumble noise. Trans fluid and filter change reduced/removed converter issue but surging remains.
Who did this work and what fluid was used?

Post #51 - new motorcraft plugs installed. (note corrosion in #4 and 7 plug wells, slight surging remains.)

Post #54 - cel and limp mode. Restart cleared cel, throttle body replaced, slight surge still present.
Did you check for codes?

Post #60 - fuel filter changed, seemed to initially helped surge issue, but now you say that surge still exists.

If you do not have a service history of the vehicle, all of your above work would probably needed to be done anyways.

See next post.

 

[Bill MacLeod]

So is the surging trans related or engine/emissions/fuel/electrical issues?

Describe exact issues, at what temp (engine, ambient and trans if possible), road grade, throttle position etc.

 

[PotatoExplorer]

So is the surging trans related or engine/emissions/fuel/electrical issues?

Describe exact issues, at what temp (engine, ambient and trans if possible), road grade, throttle position etc.

Bill MacLeod, I guess that is what I am uncertain of.

When I had the first CEL/Limp mode and the RPM surge with the torque converter rumble, I initially and instantly thought it was transmission issue. I had the transmission serviced (pan dropped/filter replaced/fluid replaced) by a trusted local shop, with some mechanics that my wife and I are friends with and that I've been using for 3-4 years now. At the time I cross referenced the materials they used to be correct (I don't know off the top of my head, but I'll dig up the paper work later). This transmission service didn't do anything as I pulled away from their lot. Driving it for a bit more (10-20ish miles?) the torque converter rumble dissipated, but the RPM surge continued on. Fearing the worst I took it to a reputable local transmission shop that has been in business probably longer than I am alive. A specialist hooked it up to a scanner and took it on a test drive. When he got back he said it had no stored codes, it threw no current codes, and he couldn't detect anything out of the ordinary - BUT, he said it most certainly had some sort of RPM fluctuation and wasn't sure if it was directly related to the transmission. He further went on to say that a variation in the RPM like that should have threw a code of some sort.

So, that is when I switched my focus from a transmission related problem to an engine/emissions/fuel/electrical problem. I was basically taking wild stabs in the dark to solve the issue (well I guess you could say they were somewhat educated assumptions).

The RPM surge seems to happen like this -
I start the car, let it warm up a minute or two. Upon the very first trip of the day, I'll get it up into the RPM surge zone of 35-45MPH with no problems. After about 5-10 minutes of driving in town, I'll get into that zone again and the RPM surge will begin to happen.
How this happens is:
1) I start off by going through 1st, 2nd and gears to about 35MPH, which is the speed limit on most of the roads near me (35, 40MPH).
2) The transmission will shift into 3rd gear, RPMs drop to about 1-1,500 RPMs and I ease off the accelerator to remain at speed limit speeds.
3) When it shifts into this zone the RPMs will begin to pulse/surge by going up maybe 100 RPM more and cycle through - so it will go up 100 RPM, then drop down 100 RPM. It seems to alternate every second, so 1 second it will be up 100 RPM, then next second it drops down 100 RPM. This happens on flat roads, hilly roads, doesn't matter. The only time it seems to not do it is when I'm going down a hill, but normally that is because I let off the accelerator all together. Given a long enough road, I think this would go on indefinitely.
So - road grade is either up hill or flat, it has been happening at all temps this winter (below freezing, above freezing, near 60-70 degrees etc...), throttle position is when I am staying at a steady speed (basically just resting my foot on the pedal to keep it at 35-40mph). I have no clue about the transmission temperatures, but it seems like it will be fine on the first few minutes of a trip, but then after that it will continue to do it no matter how long I've been driving.

To eliminate the RPM surge I either give it more gas (or switch out the O/D) to bring the RPMs up into the 2-3k area (or it shifts into the next gear), let off the accelerator all together, or slow down/apply the brakes to get out of that zone. Sometimes if I'm on a flat road and it begins to RPM surge, followed by the road beginning to go into a steady incline, the RPM surge really bogs down and the PCM seems to really resist shifting into a lower gear.

I'll see if I can get more specific about things... maybe I should just create a video also.

 

[tripplec]

I don't know if the transmission has a lockup sensor to lock the torque converter in OD. They used to use that technology long ago. Its a small change and would not throw codes. Its not happening driving in 5th from what I read. Hence ignition and fuel flow is not an issue here. Someone who knows the engine and sensors along with the vacuum system might pin point it.

 

[Bill MacLeod]

OP
All good info you posted.

Not much anyone of us can do with regards to trans fixes/repair on our own. The 6R (not sure which one you have) like many other Ford electronic trans, respond well to correct fluid type, cleanliness and proper fluid level. This is very important and sadly neglected by most. If this was my situation I would check fluid level and just how clean it really is. Maybe an ECM reset will help, but first have checked again for stored codes. Trans shop may have only checked for trans codes, diagnostic time at a Ford dealer may be money well spent. Also, hope whoever changed the fluid replaced with Motorcraft SP or LV as its proprietary and ONLY produced and bottled with Motorcraft on the label. Anything else is a crap shoot/snake oil.( jmho)
Your trans surging sounds like its searching for the proper gear while under low throttle conditions. Us older guys called it lugging the engine back in the day, but we didn't have 4,5,6 spds trans either, so we gave it more throttle.
But, lack of fuel or spark can also cause similar conditions. The fact that you found symptoms of moisture in a couple of plug wells needs to be rectified. As I mentioned before, use dielectric grease on both ends of the coil boots. A dap on the end to plug ceramic and a film where the cop seals to the head. .Could be a weak cop, but until you get a misfire code set (or stored) its only a guess.
Don't rule out dirty MAF senor wires, dirty injectors, air filter or vacuum leak.

You will find the issue.

Bill

 

[ExpoSittinLow]

I am having the same rpms surging issue that PotatoExplorer is having at 35-45mph. I noticed the issue a few weeks ago and been searching for a fix. I'm going to try and clean the MAF and also the throttle body and see if that helps.