Please Help! Transmission problem? 2004 Ford Mustang, V6/3.9

MODQUAN · 2 Weeks Ago

Hello,

I have a 2004 Ford Mustang, V6/3.9 engine, automatic transmission with roughly 91,000 miles. The past couple of days I've been experiencing what appears to be transmission problems. Idling and normal city driving is fine. However, when I get it up on the highway and go from say 50mph to 60mph it seems to skip and the RPMS rev higher then what the car is actually going. Can anyone tell me what might be wrong? I refuse to believe I already have transmission problems at only 91,000 miles.

Thanks'
Brian

cchstang · 2 Weeks Ago

How old is the trans fluid? I would try changing the transmission fluid. I had the same problem on my 95 auto it would slip and shake quite between shifts. Doing the flush made a huge difference.

ChuckV10 · 2 Weeks Ago

Remember to use Mercon V.

Around here Autozone was nearly $5 a quart.

WalMart was $3.57 for Valvoline high mileage Mercon V

MODQUAN · 2 Weeks Ago

Hi there

Thanks for your response. The transmission fluid was changed at 50,000 and is currently full and good in color. Im beginning to think it has nothing to do with my transmission now after speaking with Ford. Another thing it is doing is blowing a hole right through one of my vaccum lines. Ford said it sounds like a sensor or possibly a clogged line some where, which would cause my tranny to act the way it does.

jakksincorpse · 2 Weeks Ago

lol usually when im goin on the highway and my rpms slip my traction control light seems to always turn on too. maybe ur spinnin ur tires? lol

MODQUAN · 1 Week Ago

Hi Folks,

Took the car to Ford today and got to the root of my problem. Apparently, I bottomed out and crushed one of the catalytic converters. In doing so the impact I guess caused the honeycomb particles inside to be crushed and break into pieces blocking and restricting air flow out the exhaust. Soooo, the pressure needs some where to go and if it can't go out the tail pipe it ends up building up in the engine and causes the vacuum line to blow a hole in it releasing the pressure. This is also what is causing the transmission to appear like something is wrong with it as well. I'm replacing it tomorrow and car should be running as normal. Thanks for all your suggestions!