So I have this 94 Grand Marquis LX. 4.6L, 174k miles. I''m seriously at
my wits end here and if I can''t fix this asap, then I have to junk it.
Any help would be greatly appreciated, as I''ve tried everything I can
think of. This is what happened.



One of the transmission cooling lines was leaking. While it was leaking
it started slipping, naturally. That''s how I noticed the leak in the
first place. The car wasn''t driven while it was slipping, except to get
it back home. As soon as I got it home I replaced them both, easy job.



For the next 3 days after the fix, everything was fine. Zero slipping,
zero leaking. No problems for 3 solid days of driving. Then we parked
the car for the night and came out in the morning. The car goes into
reverse perfectly fine. No delays and no slipping. But when you put it
in drive it sounds like it engages (like the idle gets a bit lower and
you can feel the car shift a little). But in order for it to move you
need to get the RPMs up to, I''d guess, about 3k-3.5k Then it sloooowly
rolls forward and will eventually *chirp* into gear and gesture forward
quickly but if you let off the gas at all, you''ll have to get the RPMs
back up to 3k and it starts all over again. When I say chirp, i mean,
the tires chirp when it finally wants to move. But even when it engages
the RPMs are way way too high for the speed it goes. Like you''ll be
going 10-20 mph but the RPMs are through the roof.



Ever since the lines were replaced the fluid has always been up to
level. I took the pan off and just cleaned it out, the magnet had a
bunch of metal sludge on it, but that''s not too crazy to expect.



I can''t imagine what could cause this. I''m not too great with
transmissions and the fact that it was working soundly for 3 entire
days and then magically started doing this while it was sitting in my
driveway, it blows my mind.



Really, any help/insight would be greatly appreciated.



Edit: I''m not sure this would even have any effect on this issue, but
I''ll throw it out there. For a while now, I''ve had to start the car in
neutral. If you start it in park, you cannot shift out of park because
of a broken brake switch wire. It had been broken for a while and even
though it was inconvenient, it seemed to have no effect on the car''s
performance. I fixed it and then it broke again. It had been broken
(the second time) for a month or so before the above problem started.
It''s probably unrelated, but since it''s the only other problem with the
car, I figured I''d mention it. Thanks again.

 

I''m not to great on transmissions either, but I''d get a bottle of Lucas and give that a try.

 

did you reverse the trans lines when you put then back on? most of the time these are different sizes to stop this from happening. Also, did you put the correct trans fluid in. the correct kind is on the dipstick. Make sure. I know it sounds stupid but double check that you put the correct stuff in.

 

@QXXxxx:


The transmission cooling line also runs through the radiator. Yes, the radiator which cools the engine.


It does happen that they corrode, and enginge coolant is getting into the transmission lines, ergo the transmission fluid.


Once you start driving, the fluid is too thin and the converter needs more speed (higher engine rpm) in order to fill it.


I would check the transmission and radiator fluid to see if they are mixed.


Greetings!