Transmission Problem (I think...)

[Rngrs3910]

My '06 V8 EB has been having problem after problem over the past few weeks. The newest of which is a bucking that started to occur when I'm accelerating on the highway. I barely even noticed it at first as it was extremely infrequent, and would only buck once, but after i left home for a business road trip, it progressively started happening more frequently, and being more constant, and eventually began happening at lower speeds. I drove the majority of the trip with the cruise control on the highway, and on the way home called my local ford dealership and made an appointment to drop it off the next morning. (No light's came on at all during the time)
I've paid a small fortune fixing my Explorer over the past few weeks and am probably single handedly keeping the service department in business. I did some research on the internet for possible causes, but couldn't find anyone with the same symptoms, just similar. So when I went to the dealer the next morning, I told them I couldn't afford to pay more than $200 for the visit and knew that I needed a new fuel filter and transmission flush, which would total about that much. The guy at the service deparment suggested that for the same price, instead of flushing the transmission, I should flush and clean my fuel injection system, which might be getting clogged and slowing the fuel supply when I step on the gas, causing the sensation I'm feeling. So i took his advice, and when I drove off the lot the car felt fantastic. I drove around all weekend at 35-40 miles an hour with no bucking. Unfortunately this morning I hopped back on the highway, and when i stepped on the gas it bucked. Didn't happen again on the 20 minute drive to work, but clearly the injection cleaning only did so much.
Any ideas? Could a transmission fluid flush solve the problem, or should I pony up and pay the dealer the $150 it cost just to plug in the computer and diagnose the transmission for a problem?

 

[Rngrs3910]

Just found this thread on a Ford Trucks Forum. Sounds similar. A few weeks ago one of my problems was water in my engine, which fried one of my plugs. The dealership replaced the plug and coil for $350 (160 of which was running the diagnostics), so roughly 200 per plug, which is what one of the guys on this other thread got hosed for. Anyone ever done this themselves? I searched some parts on-line; the plugs don't look too bad (10-15 bucks each) but the coils look pricey. I'm not too practiced at egine work, not sure I want to try and tackle this on my own.

 

[Kriegen]

Just a shot in the dark, but if after your fuel injection was flushed and I'm assuming your fuel filter was replaced, all was working good for a while, is it possible that you have a bunch of junk in your tank that is quickly clogging up the filter? How did water get in your engine previously? Recurrance?

 

[Rngrs3910]

That's possible. I'd have to pick up the tools to take the fuel filter off myself and check it. From what I understand its a special wrench that's needed. Even if I did, I'm not sure what I'd be able to see.
As for the water, the Ford guys couldn't/wouldn't tell me. I asked and he mentioned that it was #8, in the back near the firewall, and theres a gasket near by it could have snuck through. The normal places would be in the air filter or through the gas tank. I guess its possible the water fried one plug completely and damaged a few others, but the slip from my servicing said that the computer run tests only picked up a problem with 1, and they replaced it. The water in the engine has never happend before and it's got almost 80,000 miles on it, 50,000 of which are mine.

 

[midiout]

I've always wondered is there was condensation in the tank. If you think about it, the gas we put in could have water, and if there is enough, could cause problems. When you think about running an engine below 1/4 tank, all the stuff floating above the gas would reach the fuel pump ?

 

[jupiterak]

^^^ You could have some water or bad gas. Put a couple bottles of HEET and see if that cures the problem. I also check the fuel filter just to see they replaced it. Also, clean the MAF sensor with a electrical cleaner spray or maf cleaner and reset the computer by disconnecting the battery. I'd do these before you invest the big bucks.

 

[Rngrs3910]

^^^ You could have some water or bad gas. Put a couple bottles of HEET and see if that cures the problem. I also check the fuel filter just to see they replaced it. Also, clean the MAF sensor with a electrical cleaner spray or maf cleaner and reset the computer by disconnecting the battery. I'd do these before you invest the big bucks.

Thanks for the tips. I'm going to try each of these first. I've gotten to the point where if I drive for days without having an issue if i go easy on the gas pedal, but the second i get overzealous and hit it hard, the sensation happens all over again.

With the MAF Sensor, and I going to need to remove it, or is it close enough to the intake that I can pull of the filter cover and spray the cleaner in?

 

[ZO6_Vette]

Give more info please, mileage, speed it occurs, what gear is the car in, does the check engine light flash when it happens, is it bucking or does it feel like you are driving over rumble strips.

 

[Rngrs3910]

Give more info please, mileage, speed it occurs, what gear is the car in, does the check engine light flash when it happens, is it bucking or does it feel like you are driving over rumble strips.

Truck's got 80k on it, probably around 78.5k when it started, 79k when i got the fuel filter and injection service.

At its worst it was bucking, but now it feels more like a rumble strip, each bump about 1-2 seconds apart.

Happens while accelerating, passing from 40 to 55. Only happens when i accelerate hard, other times i'll accelerate hard and it will be fine, but if I accelerate slowly and deliberately, it never happens.

Any input would be appreciated.

 

[jupiterak]

Did you ever check the fuel filter? If so, is the filter's flow direction correct?

 

[ZO6_Vette]

To me it sounds like a misfire (plug, coil or injector) but that would throw a code normally.
Could be torque converter shudder, has the trans fluid ever been replaced.

 

[patrick112390]

if you had someone that had access to some sort of a cylinder fire live stream scan tool. you could watch and when it happens, if its a bad coil/plug, it will show it... if i were to diag it and had it on the computer doing a power balance, watching one go down would narrow the problem down significantly. it would look something like - - - v - - or vise-versa if it happened and the spark was all the same - - - - - - then you could rule out the motor...thats all part of that wonderful $89.95 though

 

[bmustangguy]

A little off topic from ford but i work at a chevy dealership and we have had a couple cars come in for pretty much the same bucking problem. Turns out to be water in the fuel. Mainly from a local gas station. Ended up having to drain the fuel tank, couple actually replace fuel pump and spark plugs as well as fuel system service.

 

[seannydeez]

Just a shot in the dark, but it could possibly be the throttle positioning sensor which is a fairly inexpensive part if you get it online vs the dealer and it's easy to replace yourself. As for the transmission flush, a recent article in either the Boston Globe or Herald written by "auto experts" was saying to never do a transmission flush and on most vehicles it really isn't even necessary to change the tranny fluid, they're just another way dealers try to nickle and dime you claiming they are services you need. If the car is out of warranty you may want to ask around for a reliable independent mechanic for a second opinion.

 

[Bill MacLeod]

According to the service manual, the 6spd 6r60 trans cannot be flushed. There is a one way temp valve that only allows fluid flow thru the lines when it reaches a certain temp. (180 or something like that)
If the fluid and filter have never been changed, then its long overdue and possibly on borrowed time. And the 6spd uses SP type Mercon only.
Z06 may be on to something. Could be convertor shudder.