WWYD? LONG - '03 Merc Grand Marquis 4R70W

[tony1679]

Originally Posted By: ford46guy
Besides TQ issues, could be a misfire. I am very familiar with these cars.

It is very likely time for a tuneup(100K), and some coils may be weak. Be sure to follow all torque specs for replacing plugs.

Also, these cars leak from the intake manifold, allowing coolant to get into the coil wells and short them out. Even if they have the aluminum crossover.

A good scanner that shows mode 6 data will give you the full story. You will not see any codes.

If the car has no tuneup history change the plugs to motorcraft platnium.

I 100% agree. I am also very fluent with 4.6L 2V engines. I've owned 3. But never a 4R70W. I agree a misfire could be mistaken, but that is NOT the case here. If she purchases this car, MC "single" plats will be going in, along with MANY other parts and fluids. Diff, trans, oil, fuel filter, techron, pcv, coolant, thermostat air filter...... the list goes on.
Originally Posted By: Falcon_LS
PS: Use Mercon V only. Don't use a universal fluid that meets the spec - a fluid that just meets Mercon V.
Again 100% agreed. I personally am a huge \/ fan, but when I went to parts stores today to scout my list, I was surprised. Valvoline's Mercon V is NOT licensed or approved by Ford/Motorcraft. They list it as "for use in."

What's worse, is that going to a dealer and getting the real Motorcraft Mercon V is cheaper. By a lot (~30%). Win-win.

 

[Colt45ws]

For Mercon V I like to use Schaeffers #204SAT Full synthetic. Its Mercon V licensed and Everything I put it in ends up better. Even back when I first bought my '04 with less than 30k miles it would have some odd slip-grab-slip-grab (basically shudder) thing going on when it shifted into 2nd at wide-open throttle. Changed to the 204SAT quickly and it put a stop to that literally as soon as I put it in.

 

[tony1679]

Update - I did a pan drop and filter change. Used a Wix filter kit. Installed a Dorman transmission pan with a drain plug to make future changes easier. A little over 4.5 quarts of Motorcraft Mercon V and a bottle of Lubegard Red later, NO shudder! Shifts are much better. It still hunts for O/D a little, but a noticeable improvement.

I know.... why didn't I do a line flush? Because I've never done one before and wasn't comfortable experimenting on someone else's (especially a family member's) car. All is well in the end.

Thanks for all the help!

 

[shiny]

Glad it solved the problem. I got one of those Dorman pans with drainplug for my CV. Makes a drain-and-fill so much easier.

Ford recommends the line flush procedure every 30K miles; this is what they do at the dealership. My mechanic said he'd seen too many Panthers develop major transmission problems after a line flush. If a transmission has had regular fluid changes it'll be fine, but if it's been neglected too long a line flush can do damage.

I bought my retired CV police interceptor in May with 117K miles on it. Didn't know if it had gotten a tranny service regularly, or at all. So I opted to drop the pan for a drain-and-fill + filter change rather than do a line flush.

There was a lot of fine metal filings in the pan but the fluid that came out was pristine, cherry red. Now I know it's been well-maintained, but had probably never had the pan dropped or the filter changed.

Keep up with regular drain-and-fills and use only Mercon V ATF. Panthers can run on just about any oil, but when it comes to spark plugs and transmissions they are fussy about what you put in them. I use only Motorcraft brand for Mercon V, transmission filter and spark plugs simply because they were designed to work for these cars.

 

[DoubleWasp]

Originally Posted By: tony1679
To my knowledge (which is limited, I'm not all-knowing) a complete fluid exchange (isn't that the same as a flush?) can potentially do harm. Not because you changed the fluid (changing the fluid is NEVER bad), but because you are 'shocking' the trans. Especially if the old filter was completely clogged, and contaminants made themselves at home in the trans. Take away everything suddenly and issues can arise.

Maybe I'm an idiot spreading an old wives' tale

, but it makes sense to me. Everyone please correct me if I am wrong. But I feel the only harm I'm doing is to my wallet. But if div>


Total and complete caca. A transmission is not a goldfish. It doesn't need an adjustment period.

Of all of the used cars and trucks I have bought for myself and my business, I cooler line flushed every single one of them and never had a transmission issue pop up.

If a transmission dumps from changing its fluid, it was never going to make it anyway.

 

[Falcon_LS]

Originally Posted By: tony1679
Update - I did a pan drop and filter change. Used a Wix filter kit. Installed a Dorman transmission pan with a drain plug to make future changes easier. A little over 4.5 quarts of Motorcraft Mercon V and a bottle of Lubegard Red later, NO shudder! Shifts are much better. It still hunts for O/D a little, but a noticeable improvement.

I know.... why didn't I do a line flush? Because I've never done one before and wasn't comfortable experimenting on someone else's (especially a family member's) car. All is well in the end.

Thanks for all the help!

If a transmission hasn't been serviced in a while, even if it's just a pan drop, I usually reset the PCM to relearn the shift patterns with the new/refreshed fluid. Might want to try that and see if it solves your OD hunting issue.

 

[tony1679]

Originally Posted By: DoubleWasp
Originally Posted By: tony1679
To my knowledge (which is limited, I'm not all-knowing)...Maybe I'm an idiot spreading an old wives' tale

, but it makes sense to me. Everyone please correct me if I am wrong. But I feel the only harm I'm doing is to my wallet. But if div>
Total and complete caca. A transmission is not a goldfish. It doesn't need an adjustment period.

Of all of the used cars and trucks I have bought for myself and my business, I cooler line flushed every single one of them and never had a transmission issue pop up.

If a transmission dumps from changing its fluid, it was never going to make it anyway.
Not arguing with this, in fact I mostly agree (especially with the last part). But take an engine for example. If a neglected, sludged engine suddenly sees a massive cleaning, stuff gets knocked loose, and can end up in bad places. Call it a side effect. I understand that an engine and a transmission are like an apple and orange. But I guess I take the expensive route for peace of mind (kind of like buying organic apples), after all the only harm I'm doing is to my wallet. As long as the problem gets fixed, I am ok with a little extra leaving my wallet. Like I originally said, I'm not all knowing, and I appreciate the correction. I got the result I wanted. And I know for next time that a line flush may be the right way to go.

 

[tony1679]

Originally Posted By: Falcon_LS
If a transmission hasn't been serviced in a while, even if it's just a pan drop, I usually reset the PCM to relearn the shift patterns with the new/refreshed fluid. Might want to try that and see if it solves your OD hunting issue.
I had both battery terminals disconnected for four solid days (while replacing the intake among many other part and fluid changes). Does this count as a reset?

 

[Colt45ws]

Yeah, it does. But the EEC doesn't adjust to the trans or anything until 2005+ when the drive by wire upgrade added the input shaft sensor to the trans.
I always just modify the valve body in these transmissions. Ive done it to all 3 of mine that Ive had and assisted in or done half a dozen others.
That gets rid of the sloppy shifts 100%.