2004 Mercury Sable transmission

[Mark_S]

My daughter has a 2004 Mercury Sable with the DOHC engine. The transmission shifts smoothly when first started and for about 30 minutes. After warming up, and when starting from a dead stop, the tac will go up to about 2000 RPM's before the transmission shifts from 1st to 2nd. The shift is harsh, to say the least. Also, when in reverse, there is a knocking or bumping when the accelerator is depressed. If I put it in reverse and do not depress the accelerator, the car will slowly and smoothly move in reverse with no bumping.

When did it start? She is not sure >). The fluid is due for a change. It currently has Maxlife Dex/Merc which I put in about 60,000 miles ago (complete tranny flush, new filter, and cleaned pan). The car has about 175,000 miles on it.

The check-engine light is on, so I took it to O'Reily's to get a scan. Two codes came up. One was P0054 (Heated Oxygen Sensor) and the other was P0193 (Fuel Rail Resistance Sensor).

Any help would be greatly appreciated.

 

[SteveHarper]

60k is way too long for an atf change on that transmission. It should be every 30k. See if that improves things. My transmission felt better after a change at 30k.

Plus you should have used Mercon V not Dex / Merc. That has probably compounded the overdue atf as Mercon V is far superior to Mercon.

And from now on she should baby the transmission. Come to a complete stop before changing gear and wait a second after changing gear. Also when parking, make sure she applies the foot brake with the transmission in neutral and let the car come to rest on the brake before shifting to park.

 

[Dakota1820]

Not sure about that car but some automatics say up to 100,000 miles I would change it at 30,000. My Bet is the transmission is going bad.

 

[SteveHarper]

Ford says 30k with Mercon V and that's a full exchange of 13.4 quarts. Many feel that for that transmission 30k is too optimistic. He did 60k on Mercon.

 

[Tdbo]

As has been stated, 60K is way too long for a ATF change on a Taurus/Sable.
Never go over 35K on a ATF change on those vehicles (the transmission is the weak point on those cars.)
Change immediately with Merc V and see if it improves. If it doesn't, it is probably too late and you are looking at a rebuild or replacement.
Those transmissions will last a long time when ATF is changed frequently. I have a 2000 Taurus with 259K and the original engine/transmission and change fluid yearly (approx 35K.)

 

[Mark_S]

Thanks for the reply. The Haynes manual specifies Mercon (not Mercon V) which is the same as Dex/Merc. I know the schedule calls for 30,000 mile fluid change, but I think that is for a drain and refill, not a flush. Maybe I should flush it every 30,000.

Since the problem is always from a stop, whether forward or reverse, I suspected a defective Output Shaft Sensor, but if that were the case, it should have shown up on the scan. "Should have" are the operative words. Since everything shifts smoothly before it warms up, it has be baffled.

 

[oilboy123]

Flush it now if it has not been done in awhile. My 98 Taurus trans requires Mercon V, so I'm sure your sable does as well.

Getting it flushed out is the most prudent/cheap thing to do before spending money chasing down the problem. Having a trans filter that's getting clogged, and or fluid that is getting degraded can cause all sorts of havoc. I run about 50K + on my fluid changes, but run full synthetic Amsoil. It still shifts like new at almost 160K. Good luck

 

[Donald]

Do a complete fluid exchange including the filter. Ask to see the old filter. I would go for Amsoil, but thats just me. Maybe a Magnefine inline filter.

I would order the oxygen sensor from RockAuto. They do go bad. Get the exact replacement, not some generic one where you need to deal with the connector.

 

[oilboy123]

+1
Originally Posted By: Donald
Do a complete fluid exchange including the filter. Ask to see the old filter. I would go for Amsoil, but thats just me. Maybe a Magnefine inline filter.

I would order the oxygen sensor from RockAuto. They do go bad. Get the exact replacement, not some generic one where you need to deal with the connector.

 

[SteveHarper]

Originally Posted By: Mark_S
Thanks for the reply. The Haynes manual specifies Mercon (not Mercon V) which is the same as Dex/Merc. I know the schedule calls for 30,000 mile fluid change, but I think that is for a drain and refill, not a flush. Maybe I should flush it every 30,000.

Since the problem is always from a stop, whether forward or reverse, I suspected a defective Output Shaft Sensor, but if that were the case, it should have shown up on the scan. "Should have" are the operative words. Since everything shifts smoothly before it warms up, it has be baffled.


Even the owners manual states Mercon V. Ford standard procedure is a complete change using the cooler line. I've researched this extensively.

 

[Mark_S]

Originally Posted By: oilboy123
Flush it now if it has not been done in awhile. My 98 Taurus trans requires Mercon V, so I'm sure your sable does as well.

Getting it flushed out is the most prudent/cheap thing to do before spending money chasing down the problem. Having a trans filter that's getting clogged, and or fluid that is getting degraded can cause all sorts of havoc. I run about 50K + on my fluid changes, but run full synthetic Amsoil. It still shifts like new at almost 160K. Good luck



I used MaxLife, which is also synthetic. I've already bought a Wix filter and a Felpro gasket. How could Haynes get it so wrong with the Mercon? Thanks. I could use some good luck.

 

[01rangerxl]

Originally Posted By: Mark_S
The Haynes manual specifies Mercon (not Mercon V) which is the same as Dex/Merc.


The Haynes manual you have is out of date. Your car came from the factory with Mercon V, and Ford back spec'd Mercon V for all applications previously using Mercon.

I would do a flush with Mercon V, and continue flushing every 30K, especially on a Taurus. Some vehicles can get away with a longer interval, but if any car ever needed regular transmission maintenance it's the Taurus/Sable.

 

[01rangerxl]

Originally Posted By: Mark_S
How could Haynes get it so wrong with the Mercon? Thanks.


Haynes frequently uses old info in manuals for aging platforms. For example, the Ranger manual they have is for ALL Rangers, and most of the info only applies to 1997 and older models. There is very little info on the later models...they just slapped a picture of a 1998 model on the cover to make it look up to date.

 

[Mark_S]

Originally Posted By: 01rangerxl
Originally Posted By: Mark_S
How could Haynes get it so wrong with the Mercon? Thanks.


Haynes frequently uses old info in manuals for aging platforms. For example, the Ranger manual they have is for ALL Rangers, and most of the info only applies to 1997 and older models. There is very little info on the later models...they just slapped a picture of a 1998 model on the cover to make it look up to date.



And the manual I have was published in 2005!

Thanks for all of the replies. I will flush this puppy out with Mercon V and see what happens.

 

[ET16]

Maxlife meets the Merc V specification, no?

 

[SuperDave456]

Wow guys.
I am really surprised that nobody has posted the Maxlife PDF yet.
It IS MERCON V compatible.

I have it in my 2004 Taurus, my Sister's 2001, My '98 F-150, and my Wife's Nissan Xterra. It works like a champ in all of them.

I'd just do a cooler line flush and refresh that Maxlife. You will probably get about 7 quarts out that way. It's much easier than dropping the transmission pan.
Although that is on the Vulcan engine... Don't know much about your DOHC engine. They probably have different transmissions too.

 

[SteveHarper]

Valvoline say Maxlife meets the Mercon V standards. But Ford have not approved it. They have approved other Mercon V's. Ford generally advise against using ATF that claims to meet multiple specs.

 

[Kestas]

Ditto. As a rule, I never use any ATF that claims to meet multiple specs. Use a fluid that specifically says Mercon V.

 

[Bgallagher]

I would flush it out with maxlife and throw in a bottle of lubeguard red. It sounds like you have more issues but this will help keep it going a little longer

 

[rshaw125]

I have 2 of these cars. The DOHC Duratec engine almost always has the better transmission (AX4N). It'll say metric on the pan. The pan has a reuseable gasket unless it's been discarded. I would change the fluid with Mercon V only. Walmart sells it. Drop the pan so you can see how dirty it is.
Clean and install new filter. Usually takes around 7 quarts. Make sure vent is clean and open on top.

I have trans coolers on mine and change the fluid and filter every 30,000 miles.
If this does not improve operation I would suspect an electrical/sensor problem or a too dirty valve body.