Question about Mercury Grand Marquis

1 Answer

I have a 99 Mercury Marquis with 104,000 miles. About 15-20,000 miles ago I had the trasnmission fluid changed to see if it would fix some very rough shifting at highway speeds, none in lower gears or low speed. It fixed the problem but now it is back. It seems like it occurs comimng in or out of OD, I cannot tell which but the resulting vibration is very strong. Any ideas?

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Mercury Master
  • 6,927 Answers

Did you use the recommended fluid when the transmission was serviced?I would be more inclined to believe the fluid needs a synthetic additive to loosen up the valves in the valve body.Use lubegaurd as an additive to treat the problem you are having.This will allow the valves to move freely.

Posted on Jul 20, 2010


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

2001 mercury grand marquis reading code p305 misfire, spark plugs and coils changed

If you changed the #5 Coil then the code was wrong

You get lots of wrong codes on a ford, as a bad coil
spikes the pcm when grounding out to fire the coils
secondary side

Try putting the old coil back & walking the new one to
another cylinder,may take many days & many miles of
driving to get it fix,but better than a shop guessing, because
they hate fords

Jan 24, 2013 | 2001 Mercury Grand Marquis

2 Answers

In my Grand Marquis 1999 while i am driving suddenly o/d off light is flashing what is the problem, is that possible to be transmission oil ? thanks

Not the trans fluid

Oil only cools,lubes & applies pressure to
the clutch drums & bands

You change trans & power steering fluid
every 3 years or 30,000 miles on ALL Vehicles

Changing trans fluid DOES NOT FIX ANYTHING

You have to have the OD light issue diagnosed

May 23, 2011 | 2004 Mercury Grand Marquis

1 Answer

All of a sudden my 2004 mercury grand marquis with 55000 miles idles rough. Not really noticeable when driving but do believe there is a lack of power and mpg seems to have declined. Can u help???

The vehicle is 7 years old

The spark plugs should have been changed at 60,000
Gas filter every 3 years
Air Filter every 3 years or sooner
The MAF Sensor cleaned every year
By now the O2 Sensors are slow to respond
If they have 100,000 change the front 2 sensors
Check TPS Voltage
Check Fuel Pressure at the fuel rail
Egr Valve most likely bad
If you have COP Ignition Coils, they may be misfiring,
common ford problem

Unrelated--change trans and power steering fluids
every 3 years,never go over 30,000 miles on any vehicle

Jan 26, 2011 | 2004 Mercury Grand Marquis

1 Answer

When do I service my transmission

It is recommended to change your transmission fluid and filter every 30,000 miles. It could probably go over a few hundred miles but I don't risk it in my car.

Sep 19, 2010 | 1999 Mercury Grand Marquis

1 Answer

Transmission service

No there is no drain plug on the torque convertor , it typically holds 5 quarts of fluid at one time. While the transmission is open, check for any metal shavings on the magnet, this would indicate problems inside. make sure they change the fluid filter , before returning the transmissoin to service.

Jul 12, 2009 | 1991 Mercury Grand Marquis

3 Answers

2000 Mercury Grand Marquis has intermittent shudder (almost like it is trying to shift gears rapidly and frequently while you are driving). Someone suggested a shudder fixx type product in lieu of having...

There is no transmition products that will fix a shudder that I know of.
I would suggest having tranny fluid and filter changed first as this is the most probble cause of a shudder at that milage, but if that does not fix the problem then I would have a transmition shop check the tourq converter.

ps, the fluid and filter can be changed at most quick lube or where ever you get the oil changed.

Jul 09, 2009 | 2000 Mercury Grand Marquis

1 Answer

Transmission hesitates shifting into second and perhaps third gear when driving slow. When acceleration is positive transmission shifts smoothly. Reference "99 Mercury Transmission" as Subject when

Several things could be causing your problem:
  1. Auto transmission fluid is low
  2. Auto transmission fluid needs changing; this is an area that gets neglected by a lot of people;check the fluid and if its brown or gives off a burning smell, it needs changing. Very old transmission fluid will cause slipping in the transmission; if this is the case, it should be changed along with the filter
Hope you find that this answers your question. Best of luck.

p.s. If you have the fluid changed, make sure it's done from the tranmission pan, not through the filler tube; siphoning through the filler tube can be hazardous to the transmission, especially cars with a lot of miles

May 30, 2009 | 1999 Mercury Grand Marquis

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

116 people viewed this question

Ask a Question

Usually answered in minutes!

Top Mercury Experts

gerry bissi

Level 3 Expert

4376 Answers


Level 3 Expert

81285 Answers


Level 3 Expert

5687 Answers

Are you a Mercury Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides