My Grand Marquis with over 205,000 miles runs and drives great. I just took a long trip to Washington DC and climbing the mountains made the temperature go up which I have never seen but I also have never climbed those big steep hills. Car eventually started not maintaining speed to the point of getting down to 25 mph in a few steep climbs. Felt really like it was being restricted and would also feel like a misfire. Once back on flat ground car was driving fine after a short while. My gut feeling is telling me the transmission fluid may be foaming or losing viscosity causing the transmission to act up feeling like a misfire. Any thoughts are appreciated as I have to go back home that way over the mountains. I was pushing the car pretty hard doing 85 + mph up the hills which probably didn't help and maybe I can be more gentle to baby it home. Maybe I should visit a quick change and have the fluid changed before going home. Again this is a guess as did a partial fluid change a few years ago. It looks red and doesn't smell or look dark.
Grand Marquis feels like misfiring - transmission?
- Thread starter spk2000
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Nick1994
$100 site donor 2024
Sounds like a bad catalytic converter to me.
Sometimes they don't plug up, they'll break a chunk off and restrict flow.
Sometimes they don't plug up, they'll break a chunk off and restrict flow.
Would a clogged converter go back to normal and the bucking or misfiring went away too. just don't want to do damage to car trying to get it home.
This is actually common on the Panthers with a 4R70W. Change the transmission fluid to Mercon V and it will help. My mom's 2000 Grand Marquis did it and it went away with Mercon V.
My 2000 Taurus sets a trouble code for misfire, believe it even tells the cylinder. Any check engine light or codes? On other forums they often warn to not let a misfire go because it can quickly ruin your catalytic converter.
Scott
Scott
A transmission doesn't cause low power, Slipping will cause the RPM to flare out of control.
If the ATF gets hot enough.....It will come out the vent.
Torque Converter Clutch shudder can feel like a misfire but wont cause low power.
How hot did the engine get? (Coolant Temp)
If the ATF gets hot enough.....It will come out the vent.
Torque Converter Clutch shudder can feel like a misfire but wont cause low power.
How hot did the engine get? (Coolant Temp)
Engine did not overheat. Gauge went up and this car typically runs on the cool side. It is a gauge but no number so I cannot tell how hot it actually was but not into the red zone and I just never saw it go up before it has always been a cooler running car even in 95+ temps but that day was mostly mid 70's and even 60's in mountains.
RPM's did not change but occasionally when I let off gas then stepped back on it would give a slight sharp jolt kind of like a hard shift but not all the time.
RPM's did not change but occasionally when I let off gas then stepped back on it would give a slight sharp jolt kind of like a hard shift but not all the time.
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OVERKILL
$100 Site Donor 2021
Sounds like a dying coil. Went through similar stuff with our Expedition. My dad had one on his 2000 that would only act up when it got hot.
Originally Posted by OVERKILL
Sounds like a dying coil. Went through similar stuff with our Expedition. My dad had one on his 2000 that would only act up when it got hot.
That sounds very possible. Kind of felt like I might have been running on 4 cylinders and was way under powered but also felt like a misfire.
I think if I baby it home it will probably be ok. I am not towing it home though so at this point it's try and get a rental and scrap car if it doesn't make it.
Sounds like a dying coil. Went through similar stuff with our Expedition. My dad had one on his 2000 that would only act up when it got hot.
That sounds very possible. Kind of felt like I might have been running on 4 cylinders and was way under powered but also felt like a misfire.
I think if I baby it home it will probably be ok. I am not towing it home though so at this point it's try and get a rental and scrap car if it doesn't make it.
OVERKILL
$100 Site Donor 2021
Originally Posted by spk2000
Originally Posted by OVERKILL
Sounds like a dying coil. Went through similar stuff with our Expedition. My dad had one on his 2000 that would only act up when it got hot.
That sounds very possible. Kind of felt like I might have been running on 4 cylinders and was way under powered but also felt like a misfire.
I think if I baby it home it will probably be ok. I am not towing it home though so at this point it's try and get a rental and scrap car if it doesn't make it.
I had one that would only present itself under heavy load. Even a downshift was enough to get rid of it. The Modulars seem incredibly sensitive to misfires, as they feel far worse than on other engines.
Originally Posted by OVERKILL
Sounds like a dying coil. Went through similar stuff with our Expedition. My dad had one on his 2000 that would only act up when it got hot.
That sounds very possible. Kind of felt like I might have been running on 4 cylinders and was way under powered but also felt like a misfire.
I think if I baby it home it will probably be ok. I am not towing it home though so at this point it's try and get a rental and scrap car if it doesn't make it.
I had one that would only present itself under heavy load. Even a downshift was enough to get rid of it. The Modulars seem incredibly sensitive to misfires, as they feel far worse than on other engines.
You could have a fuel pump giving up, A ignition coil giving up etc etc.
Take it out, Get it nice & warmed up......Do some WOT passes & see if it has power.
Don't rule out the possibility of a partially clogged catalytic converter.....Especially if it only loses power during high engine loads.
Take it out, Get it nice & warmed up......Do some WOT passes & see if it has power.
Don't rule out the possibility of a partially clogged catalytic converter.....Especially if it only loses power during high engine loads.
Originally Posted by OVERKILL
Originally Posted by spk2000
Originally Posted by OVERKILL
Sounds like a dying coil. Went through similar stuff with our Expedition. My dad had one on his 2000 that would only act up when it got hot.
That sounds very possible. Kind of felt like I might have been running on 4 cylinders and was way under powered but also felt like a misfire.
I think if I baby it home it will probably be ok. I am not towing it home though so at this point it's try and get a rental and scrap car if it doesn't make it.
I had one that would only present itself under heavy load. Even a downshift was enough to get rid of it. The Modulars seem incredibly sensitive to misfires, as they feel far worse than on other engines.
This one has Waste Spark Ignition.....Right? One dying coil can take out 2 cylinders.
Originally Posted by spk2000
Originally Posted by OVERKILL
Sounds like a dying coil. Went through similar stuff with our Expedition. My dad had one on his 2000 that would only act up when it got hot.
That sounds very possible. Kind of felt like I might have been running on 4 cylinders and was way under powered but also felt like a misfire.
I think if I baby it home it will probably be ok. I am not towing it home though so at this point it's try and get a rental and scrap car if it doesn't make it.
I had one that would only present itself under heavy load. Even a downshift was enough to get rid of it. The Modulars seem incredibly sensitive to misfires, as they feel far worse than on other engines.
This one has Waste Spark Ignition.....Right? One dying coil can take out 2 cylinders.
OVERKILL
$100 Site Donor 2021
Originally Posted by clinebarger
Originally Posted by OVERKILL
Originally Posted by spk2000
Originally Posted by OVERKILL
Sounds like a dying coil. Went through similar stuff with our Expedition. My dad had one on his 2000 that would only act up when it got hot.
That sounds very possible. Kind of felt like I might have been running on 4 cylinders and was way under powered but also felt like a misfire.
I think if I baby it home it will probably be ok. I am not towing it home though so at this point it's try and get a rental and scrap car if it doesn't make it.
I had one that would only present itself under heavy load. Even a downshift was enough to get rid of it. The Modulars seem incredibly sensitive to misfires, as they feel far worse than on other engines.
This one has Waste Spark Ignition.....Right? One dying coil can take out 2 cylinders.
Oh crap yeah, didn't even see the date, you are right! Would be even more pronounced on this rig
Originally Posted by OVERKILL
Originally Posted by spk2000
Originally Posted by OVERKILL
Sounds like a dying coil. Went through similar stuff with our Expedition. My dad had one on his 2000 that would only act up when it got hot.
That sounds very possible. Kind of felt like I might have been running on 4 cylinders and was way under powered but also felt like a misfire.
I think if I baby it home it will probably be ok. I am not towing it home though so at this point it's try and get a rental and scrap car if it doesn't make it.
I had one that would only present itself under heavy load. Even a downshift was enough to get rid of it. The Modulars seem incredibly sensitive to misfires, as they feel far worse than on other engines.
This one has Waste Spark Ignition.....Right? One dying coil can take out 2 cylinders.
Oh crap yeah, didn't even see the date, you are right! Would be even more pronounced on this rig
Thanks everyone for all the thoughts on what it might be. Always good to ask here and see what others think. My sable had a bad misfire and 3 shops including a dealership could not diagnose the problem or fix it. I was almost ready to give up on it and looked up common issues and the coil pack was a known problem. Took it to a small shop along with coil pack and said he would change it for $50 but he didn't think it was the problem. It fixed the problem and he was surprised so thanks again everyone.
Ford's are notorious for NOT setting misfire trouble codes, I see them come in all the time with DEAD holes....Missing like mad with no trouble codes!
That's where Mode $06 data becomes your best friend!
That's where Mode $06 data becomes your best friend!
It's a coil. Pull all the coils and check to see if there is any oil or water in the hole. You can buy replacement Boots. I bet it fixes your issue. Do all 8. I went down this road........
Originally Posted by FastLane
It's a coil. Pull all the coils and check to see if there is any oil or water in the hole. You can buy replacement Boots. I bet it fixes your issue. Do all 8. I went down this road........
I believe this one has the 2....4 Tower Waste Spark Coils mounted to each cylinder head. So it only has 4 coils total.
It's a coil. Pull all the coils and check to see if there is any oil or water in the hole. You can buy replacement Boots. I bet it fixes your issue. Do all 8. I went down this road........
I believe this one has the 2....4 Tower Waste Spark Coils mounted to each cylinder head. So it only has 4 coils total.
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