2006 4.0L 100K MX gone wrong

[higney85]

Started out just doing 100K mile mx on our 06 4.0L 2wd explorer and it has turned into a nightmare. Prior to starting this, what was supposed to be easy, task everything worked great. I am not new to working on cars, but this issue now has me completely baffled.

Here was the start:
New spark plugs (bosch +4 plat)
engine oil change (do this every 7500-10000 miles, full synth)
trans fluid and filter change (do a drain/fill every 25K and filter/fill every 50K)
new pcv valve (every 50K)
K&N air filter recharge (every 10-15K miles)
rear diff fluid change (M1 75w-140 synth- 50K miles)
fuel filter replacement (50K miles)
throttle body clean (TB/intake cleaner- 50K miles)
MAF clean (MAF cleaner- every time I do the K&N)

Went to start it up and it was idling quite rough. driving it seemed to calm down a bit but had the "rumble strip" feeling under load. That was new.. Searched through this site and others over about a 6 hour period and decided I may have screwed up something.

Day 2:
Removed Bosch +4 plugs and installed NGK platinums (regular ones/OEM spec) gapped @ .054. No change, if nothing it was worse.

Today:
replaced MAF, PCM reset, new coil pack set, new wireset. Checked for vacuum leaks around PCV (none found) and throughout the vacuum system. No leaks found.

Where previously it just felt like hesitation in moderate acceleration (rumble strip) now this thing is pretty much undriveable. Ignition has all been replaced (checked old vs new coils when installing- wires first, no change, then new coil, no change). Fuel system WAS working fine, only thing that was done was a new fuel filter. Air filter is clean, TB is clean, tried new MAF, no change. Electronics wise there are NO check engine lights or codes (checked by OBDII scanner). I believe this is only an engine issue, but cannot narrow down the culprit. It idles very rough and when turning on A/C the RPMS drop to around 500 and come back up to the 700ish mark (normal). Ironically the RPMS are staying constant but you can feel the miss. When driving there is no question that something is wrong. Until today (meaning since I did the work) it was only slightly noticeable at idle and under heavy acceleration, now it's like its running on only a few cylinders. I have double and triple checked the plug wires, they are on there.

Any other ideas before I do the walk of shame into a shop?

 

[2000StreetRod]

check spark plug wires

Make sure wires for cylinders 5 and 6 aren't reversed.

 

[higney85]

Gave me hope, but they are correct by the diagram. Did everything 1 at a time to try and avoid that problem.

 

[higney85]

Brought it to ford. No codes.

2 spark plugs literally "dead". Tech said it was either quality control or had been dropped. NGK plats from autozone. It's at least running right but now the "rumble strip" issue goes to the transmission. Maybe torque converter or a servo bore. Waiting to hear back.

4.0 doesn't like the Bosch +4 plugs, nor "dead NGK". I guess sticking with motorcraft is the best bet. I'll reply back the end result with the "rumble strip" routine as everything outside of the trans has been done. In the couple hundred pages of threads, it seems some don't post the end result/solution. Pet peeve.

To be continued. Frustrated at only 103K and completely ocd with synthetic fluids throughout, frequent mx, and running 2 trans coolers. Towing not even close to max and no more than 1x/couple hundred miles per month.

 

[higney85]

TC and full trans R&R. They stated they could try to fix the solenoid bore first with new TC, but the quote was within 300 of a new TC and trans. $3700 w/tax. Last money being spent on this vehicle beyond an oil change.

Done with ford. 100K and done.

 

[Bill MacLeod]

Certainly sounds like you have done frequent maintenance in the past, curious whether you have done the work or a shop. What trans fluid has been used for service and what trans filters have been used?

How long have you experienced TC shutter? Did it just start this after the 100k service

 

[pzy3339]

You said everything worked great prior to the maintenance.....does that include not having the transmission issue?

I find it hard to believe the transmission went bad right when you did all this work. The only explanation I can think of for that to be the case is the rough running engine somehow did damage to the transmission.

Is the 4.0 a throttle by wire system like the V8? If so then perhaps this is as "simple" as a wiring bundle that had been damaged getting ruffled up enough during the work to crosswire or contact ground. Or something unknowingly unplugged. Hard to say but could easily be an electrical issue.

Sorry to hear about your troubles. When I first bought my '06 V8 I noticed in the first few weeks it had some behavior that appeared transmission related, thought I got ripped off. Turned out to be it was overdue for spark plugs! Never thought I would be happy to spend $110 on spark plugs.

Since you seem to have done this before I would assume no, but I have to ask. Any chance you used the wrong trans fluid?

 

[higney85]

I thought everything was fine prior, but upon talking with my wife it had been shuttering. Being that she knew I was going to be giving it a "tuneup" she thought one would fix the other. As far as who did the work, that would be me. For fluid I have always used Mobil 1 full synthetic ATF. After doing the first trains service years ago with the 1/4" NPT and suction pump it really wasn't too bad with the trans fluid level so I kept doing it myself. Never touched bands or anything beyond the fluid/filter in the trans. In the 2 days of madness trying to figure this thing out I checked the wiring harnesses after not finding a vacuum leak. Seems other had a problem with harnesses but mine looked good. I asked about it being electrical and was told that once the plugs were swapped out their full scan showed everything working correctly. I called a couple other trans shops for quotes and when telling them the symptoms both mentioned the servo bore issues with the 5r55s and said it could also be the TC. At this point it's a R&R with new TC and 3yr unlimited mileage warranty. Should be good until we sell it a few years down the line for something bigger as the family grows. It's been a good set of wheels up til now.

 

[pzy3339]

That is unfortunate. I have not purchased a car new yet so I tend to expect repairs, maybe that makes me more forgiving. It always makes me sad to hear when people who love their vehicle ends up losing faith in it after a major repair comes up.

One of the guys I work with was telling me his Jeep Wrangler unlimited(4 door) had to have some serious engine work done last week. During the conversation he told me he had another one prior to that and he had the engine replaced 4 times!

I guess my point is if you end up looking for a new vehicle you might be able to do better, but you can for sure do worse. My philosophe these days is to drive something worth fixing because nothing lasts forever

 

[higney85]

Well picked it up today. So far so good, minus the dent to the checking acct.

The part that really is frustrating is not the money or aggravation, but instead the idea that being on top of Mx isn't enough to keep a vehicle running over 100k miles in today's day in age.

 

[2000StreetRod]

Warranty dependent

I purchased a new rear wheel drive Grand Cherokee last year to avoid constant velocity joint failures associated with front or all wheel drive. So far there's a recall for the electronic stability control (ESC) failures, inadequate alternator capacity, a fire hazard for the sun visor vanity lamp wiring after a service repair to the sun visor. Additionally, my service air bag advisory has been coming on almost every time I stop the vehicle at a traffic light or sign. A couple days ago my heat came on even though my A/C was selected and the temperature was set way below the cabin temperature. I had to shut off the engine to reset the heat/air conditioning controls. Most of the problems are electrical/electronic in nature.

It used to be if you purchased a new vehicle almost all of the trips to the dealer were for lubrication/coolant servicing. Currently, most of the trips to the dealer are for warranty work. I just wait until a scheduled oil change and then authorize one recall work at the same time. It's been over a year since the 2014s have been sold and there still is not a higher output alternator available. At my last oil change I authorized the ESC recall work but the machine to reprogram the function wasn't working. There's enjoyment in driving a new vehicle but also a lot of aggravation.