Transmission or torque converter?

[OVERKILL]

Originally Posted By: Trav

He said he is reading misfire count so i assume he is accessing it with a scan tool capable of mode 6.



My scanner shows misfire count too, but since I don't have the Ford "module" for it, I can't see any real-time data or access the non-CEL misfire count. But it shows the area that I should be able to see them, they just don't populate.

 

[jrustles]

Originally Posted By: Falcon_LS
2001 Mercury Grand Marquis with a Ford 4R70W. When I fired her up this morning, there was a strong shudder until the rpms dropped and everything went back to normal.

As I was driving, I noticed the car would start to shudder when accelerating, which I thought was quite weird. Then when I was coming home this evening, the transmission randomly downshifted and I lost forth gear. At one point, I released the gas and it upshifted into forth all by its own but downshifted as soon as I touched the gas.


Dear Falcon,

long time lurker here, and had to sign up when I read this. The problem you are having may be transmission related indeed. Have you heard of the "servo bore" wear problem with the 5r's? It affected all 5r's and I believe the 4r's as well but I'm not 100% on this.

There is a servo that actuates one of the brake bands, and a notch in the servo pin which opens and closes the channel. Due to the way the servo pin is machined (a latent defect), the edges of the notch will eventually wear out the bore in the aluminum case, causing pressure leakage, leaving the servo either stuck on, in between, or off. This will cause the transmission to attempt to drive in between two gears (and will quickly burn out the band). There is lot of info about this issue on the net, or if you know a mechanic that has dealt with this problem before who could quickly identify it.

keep us posted

 

[Trav]

Originally Posted By: OVERKILL
Originally Posted By: Trav

He said he is reading misfire count so i assume he is accessing it with a scan tool capable of mode 6.



My scanner shows misfire count too, but since I don't have the Ford "module" for it, I can't see any real-time data or access the non-CEL misfire count. But it shows the area that I should be able to see them, they just don't populate.


I use the same scan tool, the auto enginuity with all the major advanced modules.
Unfortunately i don't have a Ford here that vintage to try it on.
Did you see the article from motors?

Now i'm curious.

 

[Rand]

I had same engine and transmission.. when mine did that it was a bad spark plug wire.

a coil pack went out a few months later.

 

[Doog]

Originally Posted By: Rand
I had same engine and transmission.. when mine did that it was a bad spark plug wire.

a coil pack went out a few months later.


+1 That was my guess.

 

[OVERKILL]

Originally Posted By: Trav
Originally Posted By: OVERKILL
Originally Posted By: Trav

He said he is reading misfire count so i assume he is accessing it with a scan tool capable of mode 6.



My scanner shows misfire count too, but since I don't have the Ford "module" for it, I can't see any real-time data or access the non-CEL misfire count. But it shows the area that I should be able to see them, they just don't populate.


I use the same scan tool, the auto enginuity with all the major advanced modules.
Unfortunately i don't have a Ford here that vintage to try it on.
Did you see the article from motors?

Now i'm curious.


Forgot we had the same software, LOL! Yes, I did (read the link posted), good little blurb, but it wasn't clear to me whether it applies to his car or not with respect to mode 6. Was there a specific line in there that made you conclude that it wasn't supported on his car?

 

[The_Eric]

What about a cylinder contribution test?

 

[Trav]

Originally Posted By: Overkill
Forgot we had the same software, LOL! Yes, I did (read the link posted), good little blurb, but it wasn't clear to me whether it applies to his car or not with respect to mode 6. Was there a specific line in there that made you conclude that it wasn't supported on his car?

Yes This one..
Quote:
Let's look at a misfire diagnostic example. GM has great misfire diagnostics in its enhanced (non-OBD II generic data) with the misfire counter parameter (see my scan tool misfire diagnostics column in the April 2001 issue of Motor). Ford does not support a historical misfire counter like GM does


Maybe i don't understand this right. Do they mean it doesn't maintain a history of the misfire count once the current drive cycle is finished?
Can it still read misfire count for a complete drive cycle?

I need a Ford to hook up.

 

[SwampSurvivor]

Originally Posted By: Trav
Originally Posted By: Overkill
Forgot we had the same software, LOL! Yes, I did (read the link posted), good little blurb, but it wasn't clear to me whether it applies to his car or not with respect to mode 6. Was there a specific line in there that made you conclude that it wasn't supported on his car?

Yes This one..
Quote:
Let's look at a misfire diagnostic example. GM has great misfire diagnostics in its enhanced (non-OBD II generic data) with the misfire counter parameter (see my scan tool misfire diagnostics column in the April 2001 issue of Motor). Ford does not support a historical misfire counter like GM does


Maybe i don't understand this right. Do they mean it doesn't maintain a history of the misfire count once the current drive cycle is finished?
Can it still read misfire count for a complete drive cycle?

I need a Ford to hook up.


We drove it for a month (probably much longer than it should have) though many drive cycles. Code readers said there were no DTC's stored.

I'm not sure what the garage did (but I'm assuming pulling individual coils) but they did find the problem. It was the #7 coil

Anything below 1500RPM with any load and cyl7 was completely dead. Above 1500 it would misfire and around 3000 it would work perfectly.

My jeep will misfire on occasion on hot restart and I get a flashing check engine light and it logs a bunch of data for when it happens.

 

[zzyzzx]

Did you check the transmission fluid level?

I would be checking the TPS.

 

[OVERKILL]

Originally Posted By: Trav
Originally Posted By: Overkill
Forgot we had the same software, LOL! Yes, I did (read the link posted), good little blurb, but it wasn't clear to me whether it applies to his car or not with respect to mode 6. Was there a specific line in there that made you conclude that it wasn't supported on his car?

Yes This one..
Quote:
Let's look at a misfire diagnostic example. GM has great misfire diagnostics in its enhanced (non-OBD II generic data) with the misfire counter parameter (see my scan tool misfire diagnostics column in the April 2001 issue of Motor). Ford does not support a historical misfire counter like GM does


Maybe i don't understand this right. Do they mean it doesn't maintain a history of the misfire count once the current drive cycle is finished?
Can it still read misfire count for a complete drive cycle?

I need a Ford to hook up.


When my Ford guy hooked into the Expedition he was able to see like 700 misfires on cylinder #8, the rest were all zero. I'm not sure if that was historical or for the current drive cycle, but it definitely pointed the finger at #8 coil.

 

[Trav]

OK thanks for that Overkill.

 

[OVERKILL]

Originally Posted By: Trav
OK thanks for that Overkill.


No problem

 

[Falcon_LS]

Thanks very much for everyone's input. This was certainly an eye opener, considering just how many different things it could be.

I have a quick question. Could this, by any chance, be the MLP sensor?