08 FWD transmission issues after TSS/OSS replacement

[camboking123]

Hello

 

First time poster here! A little background, I drive a 2008 edge with ~85,000 miles for my main mode of transportation. I have never had transmission issues before and the car has been great up to this point. Likewise, the vehicle was purchased new from the dealer.

 

Two weekends ago my GF and I take a short road trip of about 60miles. On the way back, while cruising at about 75mph on the highway, the speedometer without warning drops to zero, the odometer reads "------" and the display signals an ODO error. A quick google search reveals that this is textbook transmission sensors issues on Edges and that slowing down will put the car into a safe mode (5th gear supposedly?). Given that apple maps was signaling traffic congestion ahead I decided to pull off while we could and call a tow truck. I want to add that the "thud" you get shifting between park/drive/reverse is really strong! Feels like you are hitting a speed bump or something....WOW

 

The next morning I called in sick and spent half a day trying to get a quote to replace the OSS and TSS sensor. Finally settled on a shop that came in at ~$715 parts plus labor and had mostly good reviews (~4.5/5). Had it towed over there, shop diagnosed the OSS as issue and agreed that it would be wise to include the TSS as well, 3 days later (Ford sent the wrong part apparently so it took longer) I get my car back.

 

Now, when chatting with the mechanic they indicated that there were small metal shavings/debris in the pan when they drained the fluid. Note, I have never had the transmission flushed or drained before. I asked how large and they said small, but just large enough that you could see and feel them. They had the opinion that the particles in the fluid might have caused the sensors to go out and this might happen again (covering there ass maybe who knows?).

 

So at this point I am starting to worry that there are some serious transmission issues. I have been hearing for about a month what I can only described as a knocking/marbles rolling. It only happens in gear and only happens under load/acceleration around 30-40mph.

 

Fast forward to this Wednesday, I am driving home on the freeway and I get a very small but noticeable thud, wrench light comes on, and the car becomes more sluggish. I do not loose the speedometer. I drive straight to the shop, light turns off 1/4mile away and the car comes back to life. They scan the computer, do some tests and drive it around....they find nothing.

 

Thursday I am noticing some weird behavior switching between drive and reverse (very small thud) and also what looks like leaking. (To be fair I am on edge at this point and noticing everything so it may have been nothing). The knocking was particularly bad that day (colder out) so I take it back. Mechanic concludes that the knocking noise is from the engine but as far as they can tell, nothing it wrong with the transmission. He says to bring it after work Friday so that can diagnose the engine noise Saturday.

 

I drive to work today and get another very small thud when pulling into the parking lot. Wrench light comes on, when I turn the car off/on the light goes away and the car drives normally.

 

Fast forward to this afternoon, sitting in some traffic and the wrench light comes on again accompanied by the car going into safe mode AND the check engine light is now on. It seems to get stuck in a low gear with noticeable gear wine. I pull off and the car pops into the safe mode gear so I drive to the shop. Again, the light turns off and the car returns to normal just before I get there. The mechanic can't seem to replicate it.

 

This seems to happen almost exclusively in 1st gear with really really low pressure on the gas pedal, i.e. pulling into a parking lot; crawling in heavy traffic; ect.

 

Would love to hear peoples thoughts on this. Is my transmission on its way out? Is the engine issue and transmission issue related? Just trying to become more educated on the topic.

 

Likewise, the cherry on the topping is that this had to happen the week before thanksgiving!!!! I am supposed to drive LA to PHX next Wednesday night.

 

Thanks!

 

Cameron

 

 

[WWWPerfA_ZN0W]

There are a few issues with the first gen transmissions. The thud shifting to reverse could be a transmission range sensor (TRS). You can pull off the TRS connector at the transmission and verify the resistance values on the pins, that will tell you if the TRS is the issue or not. The PCM has to relearn the new parts once installed, and it is normal procedure to leave the battery disconnected the entire time the work is being done. To make sure, you can perform a KAM reset procedure to force the PCM to relearn.

 

Did they inspect the valve body and solenoid body assembly when they were replacing the TSS/OSS sensors? If they found shavings in the old fluid, those parts should have been inspected and verified at the very least. Fine shavings are bound to be found if it is the original fluid, as the transmission "breaks in". Debris, however, can clog the hydraulic passages in the valve body, causing pressure issues, as well as possible bore wear inside the valve body. The valve body is an engine of sorts with pistons and plungers, so having debris in there is just as bad as in an engine. The solenoids in the solenoid body should have their resistance values checked to make sure they are energizing de-energizing properly, and very likely should have the gasket/filter screen replaced at a minimum.

 

Where is the leak coming from? If it is the front cover, that is likely due to the work that was done. If your Edge is AWD however, there are other possibilities, like a leak at the transmission-PTU junction, or the PTU vent, or the PTU-axle junction.

 

Marbles rolling is typical of broken down catalytic converters, so yes, I would inspect plugs/coils/PCM right away. More importantly, if you do not have Forscan Lite and an OBD II adapter, buy them and see/learn how your Edge is behaving. You can see what codes are set in the PCM for yourself. Then check engine operation status. Fuel trims, long term and short term, as well as oxygen sensor readings being of particular importance. If the cats are running hot, there is a problem in the fueling or in the cats. If the cats are noisy, well ... replacement is in the offing.

[camboking123]

Excellent response thanks!

 

You can pull off the TRS connector at the transmission and verify the resistance values on the pins, that will tell you if the TRS is the issue or not.

Will look into this thanks.

 

The PCM has to relearn the new parts once installed, and it is normal procedure to leave the battery disconnected the entire time the work is being done. To make sure, you can perform a KAM reset procedure to force the PCM to relearn.

When I got the car back, the battery had been disconnected since the clock was reset. The Wednesday I took it back they indicated that they did some sort of recalibration and this has been happening consistently ever since. Maybe a reset needs to be done again.

 

Did they inspect the valve body and solenoid body assembly when they were replacing the TSS/OSS sensors? If they found shavings in the old fluid, those parts should have been inspected and verified at the very least. Fine shavings are bound to be found if it is the original fluid, as the transmission "breaks in". Debris, however, can clog the hydraulic passages in the valve body, causing pressure issues, as well as possible bore wear inside the valve body. The valve body is an engine of sorts with pistons and plungers, so having debris in there is just as bad as in an engine.

Short answer is the office manager told me the mechanic cleaned it "out up in there" before refilling. To what extent they inspected it I am not sure. Your point is well taken though as one of the first things the mechanic said on Wednesday is we told you this might happen again, to which I said, "If this was going to fail in 100miles why did you even put the parts in there?".

 

The solenoids in the solenoid body should have their resistance values checked to make sure they are energizing de-energizing properly, and very likely should have the gasket/filter screen replaced at a minimum.

Will also look into this thanks.

 

Where is the leak coming from? If it is the front cover, that is likely due to the work that was done. If your Edge is AWD however, there are other possibilities, like a leak at the transmission-PTU junction, or the PTU vent, or the PTU-axle junction.

My thoughts exactly. Thursday's visit concluded that the leaking was from a cooling hose and not from the work they did. Probably need to get under there myself and check for sure. Car is a FWD fyi.

 

Marbles rolling is typical of broken down catalytic converters, so yes, I would inspect plugs/coils/PCM right away. More importantly, if you do not have Forscan Lite and an OBD II adapter, buy them and see/learn how your Edge is behaving. You can see what codes are set in the PCM for yourself. Then check engine operation status. Fuel trims, long term and short term, as well as oxygen sensor readings being of particular importance. If the cats are running hot, there is a problem in the fueling or in the cats. If the cats are noisy, well ... replacement is in the offing.

Funny you say this as I purchased a OBO II adapter but never got it work. I will have to give Forscan Lite a try..thanks! I want to add that the noise reminds me of a diesel car when it occurs so maybe marbles is the wrong description. Would I hear this in the front or the back...as of now the noise seems to be coming from the front exclusively and only under load. That being said, plugs/coils are something I was thinking might be worth looking at.

 

Thanks for the informative reply! I will probably be getting a rental car for my trip to avoid this hassle on the road.

 

[macbwt]

I would definitely investigate the coils and plugs. Would not hurt to have the PCM diagnosed also.

[camboking123]

I wanted to post back to close this out.

 

Mechanic spent about 2 weeks with the car. We ended up rebuilding the trans with a 2year warranty after trying a number of other things. I went over to take a look at the shop and it looked like one of the bearings partially failed and released about 3/4 of the bearing shield into the transmission. Looks like it caused some sort of cascading effect. The oil had a significant quantity of large metal fragmentation, large enough to see and feel. The gears inside looked like they got blasted with a sand gun. This must have happened during my drive and just got worse with time. Maybe this caused the sensors to fail somehow.

 

As to the scratching noise under load, this was an unrelated issue that was related to some loose hose. Honestly I can still kind of here it, but its not nearly as bad as before and I will monitor.

 

Its going to take me a while to trust the car again after this, transmission issues really put you on edge!

 

Hope this helps someone in the future.

 

Best

[WWWPerfA_ZN0W]

Best of luck with the transmission, at least now you have a warranty to fall back on

[camboking123]

Thanks, my thoughts as well!

 

I have a few more questions.

I am noticing a slight bump when rolling at low speeds and hitting the accelerator that I didn't notice before the rebuild (that I can remember) The below thread describes it pretty well. Is it possible that an old logic was installed when they refreshed everything? I would like to chat with the shop that did this with a little background if anyone has some.

http://www.fordedgeforum.com/topic/686-transmission-jerks-at-low-speed/

 

The scratching is engine pinging. It isn't that bad but its enough to bug me. I am hoping to get some thoughts on this as I am taking it to a shop near my work to troubleshoot. As mention above I would like them to inspect the plugs/coils. Anything else I should have them inspect? Intake manifold? Anything else.

 

The pinging comes and goes. Some days it is almost non-existent. It tends to be better when the engine is warmed up. Sometimes it completely goes away when warm. Its most noticeable under light acceleration holding between 2-3k rpm, especially onto the highway/uphills

 

Thanks!

 

Cameron

[WWWPerfA_ZN0W]

Could be a simple PCM recalibration is needed or you are now noticing this problem because the transmission is not occupying bandwidth But yes, definitely check the plugs, and be prepared to replace plugs, coils AND PCV valve. These engines do ping lightly when running lean, by design, but it is not frequent. Unless you are slugging the engine going uphill, it should not ping, if all is running well. Have you tried better gas and/or higher octane fuel? A lot of winter gas is sketchy, sometimes at namebrand stations too.

 

I would buy and keep a set of the plugs and coils, better to have them on hand when the time comes, because it WILL come. Replace the coils, if the old coils look good, hang on to them as backup if you like.

Kit part number: BA5Z-12259-A

[camboking123]

Hi all,

 

I ended up doing some service myself over the weekend. Did sparks, coils, gasket (thanks for the kit part # Perf), PCV valve, cleaned the MAF and throttle body. Sparks were at .075 pretty much across the board and looked pretty normal from what I can tell. None of the coils looked bad. Right off the bat, I am still getting some pinging and its hard to tell if its better or not (probably not). I did solve some issues I was having with the car stumbling/hesitating in overdrive. Not sure if there are any other things I can do myself. I may just have to live with it and try to avoid hitting the pedal hard when its warming up.

 

Best

 

Cameron

Edited January 23, 2018 by camboking123

[WWWPerfA_ZN0W]

Light pinging is normal, as the programming is set to run the engine as lean as possible. Should really only happen under heavy load if at all.

 

Have you tried running Techron Concentrate Plus through the fuel tank? Do you use Top Tier fuel?

[camboking123]

When this started I was running costco gas, switched to Shell and or Chevron and it seemed to get better...but it also go warmer out so I am not sure gas had an impact. I have not tried any additives. I can definitely give that a shot and see how it goes.