Hello, everyone. I'm new to the forum and looking for some advice on a problem with my 2001 Expedition. It has the 5.4L engine.

When I start my suv in cold mornings and put it in drive, I experience the lack of power. When I step on the gas peddle, I can feel the engine revving and but lack of power transfer to the wheels. This goes on for about a block and then it drives normal. This happens sometimes during the day but not all the time. I have replaced all 8 coils and spark plugs. The transmission fluid was replaced about 20k ago and it's at the appropriate level.

Thx for the help.

iScream.

 

Was the trans filter changed at the same time as the fluid?

 

Hanky. The filter was replaced. Thx.

 

I've ***VERY*** limited experience with transmissions, but, from the little I know, this sounds like one of the bands is slipping when cold, which leads to it warming up through friction, which, in turn, eventually stops the slippage, which restores the power to the wheels. Greasemark, Hanky, Hayapower ... what do you think?

 

Hi Dan,
You know when I thinks I falls asleep.
If the engine is running as stated , I would suspect the torque converter is draining back into the sump. If the converter is draining back into the pan you should see a very high fluid level on the trans dipstick after it sets overnight. If that is the case it takes a few minutes for the converter to fill and transfer power to the rest of the trans. Something iscream can try is to run the vehicle a few minutes before putting into drive and taking off. If the problem is gone that would to me confirm a drainback problem in the front pump assy.
I also would like to know what Hayapower and greasemark think about this problem because i'm sure they have more auto trans experience than I.
I forgot about the EPC solenoid. If that isn't adjusting the trans pressure correctly also the fluid temp sensor could be involved. I'd better stop while I' m ahead,,,,,,,,I think.

 

Thx. Guys.

Hanky. If I let it warm up for a few mins, or even put it in drive and hold the brake for a minute, then take off, it drives normal. The problem is more severe during cold days/mornings than other times.

Thx.

 

Have a scan tool hooked up to it and look at the transmission fluid temperature sensor. The ones at the parts store will not work. If you can get the readings post them back. Sounds like that might have some bearing on your problem.

dcv/deg dcv/deg dcv/deg dcv/deg
TFT .5-2/210-110 .5-2/210-110 .5-2/210-110 .5-2/210-110

So if the temp is less than 110 degrees, voltage should be higher than 2 volts dc

 

This generally wouldn't be a convertor drainback issue, as the fluid is pretty well circulated in about 5 seconds after the car is started. Is the trans just plain old fashoined slipping? Is the engine racing but the power not going to the wheels? These came with either the 4R70W or the 4R100 trans. Which is yours?

 

Thanx from my side also !