My 96 Grand Marquis is experiencing a random shudder issues mainly during light acceleration. It is not constant and occurs very randomly but usually more under a load such as climbing a hill. I am thinking it is transmission related but not sure. Any thoughts?
Car shudder
- Thread starter spk2000
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Switch your transmission fluid to Mercon V. This was originally used to stop shudder on the 4R70W transmissions.
I experienced something similar in our Freestar van. You can review the responses I received when I posted about it here:
http://www.bobistheoilguy.com/forums/ubb...553#Post3124553
The Lubegard Red helped quite a bit, but did not eliminate the problem. I'm going to change the ATF to Valvoline Mercon V this weekend and see if that helps.
http://www.bobistheoilguy.com/forums/ubb...553#Post3124553
The Lubegard Red helped quite a bit, but did not eliminate the problem. I'm going to change the ATF to Valvoline Mercon V this weekend and see if that helps.
Will this shudder cause damage to drive it until I can get it checked out? It does this throughout the gears so I do not think it is just the torque converter.
Could be misfire?
Originally Posted By: spk2000
Will this shudder cause damage to drive it until I can get it checked out? It does this throughout the gears so I do not think it is just the torque converter.
Wellll! You certainly want to get it checked out ASAP! A shop may tell you that you need a new transmission when a good drain & refill with the proper ATF "MerconV", including the torque converter if it's equiped with it's own drain plug as on many FORD's
This is the route that I'd go first.
Originally Posted By: cjcride
Could be misfire?
Yeaaa but, these transmissions were known for this issue...I say "issue", not "problem" Even if this occures late in the vehicles life! Or the wrong ATF was used w/o the owner knowing it(Fast Lube Shop)
Believe it or not, back in ~'98, I cured this issue in a friends '95 Grand Marquis by using some Honda Genuine ATF of the day.
* DON'T DO THIS! ^^^ But, it worked
Will this shudder cause damage to drive it until I can get it checked out? It does this throughout the gears so I do not think it is just the torque converter.
Wellll! You certainly want to get it checked out ASAP! A shop may tell you that you need a new transmission when a good drain & refill with the proper ATF "MerconV", including the torque converter if it's equiped with it's own drain plug as on many FORD's
Originally Posted By: cjcride
Could be misfire?
Yeaaa but, these transmissions were known for this issue...I say "issue", not "problem" Even if this occures late in the vehicles life! Or the wrong ATF was used w/o the owner knowing it(Fast Lube Shop)
Believe it or not, back in ~'98, I cured this issue in a friends '95 Grand Marquis by using some Honda Genuine ATF of the day.
* DON'T DO THIS! ^^^ But, it worked
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I have owned this vehicle for nearly 3 years and close to 40,000 miles. I have not done anything to the transmission fluid and it is now just over 120,000. Not sure if it was ever changed but I think this will be a good start to see if it goes away. Being a 96 I do think the torque converter has a drain plug but I have not looked. I might just have the full system flush done. I have had good results with this using the BG system.
Yea, give it a good flush and some new(Proper) ATF
And maybe too, reset the ECM. I don't typicaly reset the ECM after an ATF Change but, I hear lots of folks say it's always good to do so!
And maybe too, reset the ECM. I don't typicaly reset the ECM after an ATF Change but, I hear lots of folks say it's always good to do so!
Originally Posted By: spk2000
I might just have the full system flush done
If you do make sure they use actual Mercon V fluid and not a universal with a conversion additive.
I might just have the full system flush done
If you do make sure they use actual Mercon V fluid and not a universal with a conversion additive.
Check the intake manifold for a coolant leak. Sounds like a misfire to me and the intakes are famous for leaking coolant and causing a misfire. If not leaking probably just a coil failing.
spk2000, try this next time it happens:
Keeping your foot steady on the gas, use your left foot to gently tap the brake pedal, just enough to light the brake lights. If the shudder stops immediately, then you have the infamous torque-converter clutch shudder and a fluid change will fix it. If it doesn't, then you prolly have a misfire. Could be bad plugs, bad wire(s), or a bad DPFE...all are common.
If it IS the TCC shudder, then use only real Mercon V, not some one-size-fits-all. A complete fluid exchange is preferred, but several drain & fills will get the job done. Your car does have a drain plug on the torque converter...Ford decontented those in 2001.
Keeping your foot steady on the gas, use your left foot to gently tap the brake pedal, just enough to light the brake lights. If the shudder stops immediately, then you have the infamous torque-converter clutch shudder and a fluid change will fix it. If it doesn't, then you prolly have a misfire. Could be bad plugs, bad wire(s), or a bad DPFE...all are common.
If it IS the TCC shudder, then use only real Mercon V, not some one-size-fits-all. A complete fluid exchange is preferred, but several drain & fills will get the job done. Your car does have a drain plug on the torque converter...Ford decontented those in 2001.
Originally Posted By: RF Overlord
spk2000, try this next time it happens:
Keeping your foot steady on the gas, use your left foot to gently tap the brake pedal, just enough to light the brake lights. If the shudder stops immediately, then you have the infamous torque-converter clutch shudder and a fluid change will fix it. If it doesn't, then you prolly have a misfire. Could be bad plugs, bad wire(s), or a bad DPFE...all are common.
If it IS the TCC shudder, then use only real Mercon V, not some one-size-fits-all. A complete fluid exchange is preferred, but several drain & fills will get the job done. Your car does have a drain plug on the torque converter...Ford decontented those in 2001.
Yes, this exactly.
spk2000, try this next time it happens:
Keeping your foot steady on the gas, use your left foot to gently tap the brake pedal, just enough to light the brake lights. If the shudder stops immediately, then you have the infamous torque-converter clutch shudder and a fluid change will fix it. If it doesn't, then you prolly have a misfire. Could be bad plugs, bad wire(s), or a bad DPFE...all are common.
If it IS the TCC shudder, then use only real Mercon V, not some one-size-fits-all. A complete fluid exchange is preferred, but several drain & fills will get the job done. Your car does have a drain plug on the torque converter...Ford decontented those in 2001.
Yes, this exactly.
Those TC issues are well documented.
Note that Lubegard red label was once specifically mentioned in a Ford TSB for exactly this problem...
Note that Lubegard red label was once specifically mentioned in a Ford TSB for exactly this problem...
I did take the overdrive off above 40 mph and the shudder was still there. I think this would mean it's not in the torque converter. I do have a slight antifreeze odor after driving a while so thanks RoadKing for the advice on checking for the coolant leak. How would you be able to detect the leak into the manifold though. No coolant in the oil showing up.
Added red Lubegard and problem is now gone so it does seem to be a transmission issue.
Note that many modern slushboxes use TC lockup in all forward gears but first, partial, complete, or anything in between.
That is why the OD off button didn't work for you as a diagnostic, the TC still locked up even in the next gear down...
That is why the OD off button didn't work for you as a diagnostic, the TC still locked up even in the next gear down...
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