My 1994 Gran Marquis growls.....upon starting. Ford dealer says it is the computer. In addition, Just recently it has not "hissed" when I have turned off the motor from driving and closed the doors...whatever air release that use to work has stopped....what is this?

There should be an access door on headliner.if not, you'll have to remove, lower headliner...I would start at the fuse panel and make sure the fuse is ok

You need to find the Electric draw in the system. The first thing would be a Diode test on the Alternator. Free upon request at Autozone, Advance, or Oreilys.

If you have Air-Ride suspension, turn it off overnight and see if car height deflates and the Battery stays up. A little harder to check would be the Rear Window defroster which can activate without an indicator light showing.

After that, suspect a hanging Relay, which is continuing to supply power after the Ignition switch is off.

The Dealer has a machine which plugs in between the wiring harnesses. Since some connectors have 100 pin connectors a great deal of test time is saved by testing 100 circuits at once instead of manually testing them 1 by 1.

it's the starter. happened to me about a month ago.

There appears to be a pattern of premature failure of seatbelt pretensioners in the mid-2000s Gran Marquis, especially the 2005 model year. See carproblemzoo.com or NHTSA complaints. Ford dealer wanted $103 for diagnosis and $501 for replacement of the part.

Throttle problems. I would recommend the dealer or a shop that does FORD repairs and has the proper equipment to diagnose and repair this problem.

sizes are: 215 75 R15 and 225 75 R15

Just get a piece of the rotting fuel line so that you will be assured of getting the right size. Take it to a shop that sells car accessories, and ask them for enough to do your car. Also get new clamps. Start at the fuel tank, undo the clamp, pull off the old hose , put on the new one, do up the new clamp, and then just follow the old hose along, replacing it with the new one as you go. At the far end. do the same... undo the old clamp, put the new hose and clamp on. But I forgot to tell you about the fuel filter. Replace this while you are doing this job.

it might be a bad ignition moduale. or could be a bad ignition coil

take it to dealer and get the scrappage on it against a new car.Most likely cause is low on fluid ---BUT --- anything from a worn pump to a worn front clutch

bob go to a ford dealer and get a farctory gas line DO not take short cuts on this .ive seen many of them burn