2000 5.4 Expedition w/limited slip trans. stalling

[kosinar]

This car was sitting in the garage for more than year and now it is realy lazy almost not drivible. When I shift to D and start moving it was fine. Plenty of power to get car moving. When driven on interstate at 60-65 mph rpm would stay around 2000 all the time. When I approach the hill car does not downshift to maintain the speed but start stalling. When I stepped on the gas it got even worse, it will almost stop. I have to pull into right lane and slowly recover speed. First I thought that it was transmition filter so I replaced it and the fluid. (I had the similar problem on my 1994 explorer while back and this solved the problem). After refilling the transmition it took for ever for transmition to even engage. I was reving the engine with gear shifted to drive and car was sitting in the place. Gradually it started engaging but still with long delay. Now I got check the engine light ON. Could it be transmition failing to shift or mayby catalytic converters plugged. I will go to local Advanced Autoparts Saturday to have them read error codes to get some idea. Any input is appreciated.

 

[ELVATO]

Just curious, though this doesn't help with the transmission issue. Did you put in new gas after it sat for a year, or are you still using the same gas from a year ago? Gas doesn't like to just sit around for long periods of time.

Also, how many miles do you have? The CEL codes should hopefully help diagnose what the issue is.

 

[kosinar]

Thanks for reply.
I already burned few tanks of gas since I started driving it again. I think that problem got gradually worse. I am puzzled about problem with transmission after I replaced transmission filter and fluid. That thing just does not want to shift. There is long hesitation before transmission actually engage and car starts moving. Reason why i think that catalytic converters are clogged is because even in park engine is having trouble to get in high rpm when I hit the gas. There is no misfiring or rough idle. The other unusual thing is that after I start the car compressor runs forever before it stops. I do not hear any air leak.

 

[nvycrmn]

i would change out fuel filter and air filter, if you havent already done it. that could be one of the problems...just not getting enough fuel through the system when you need it. as for transmission, when you changed filter and fluid, did you re-use the fluid that was already in there or put in new fluid? sometimes people have problems when they put in new fluid so lots of people just filter out the old fluid and put it back in the tranny. as for the compressor, you may not hear an air leak but there could be a slow leak from the bags because it sat so long.

 

[kosinar]

I did use new Dextron 5 transmision fluid per Autozone recommendation. Thanks.

 

[ELVATO]

I hope your mean Mercon 5...

Your manual states that you need to use Mercon V ATF for 4R70W transmission (13.9 qts) or Mercon ATF for the 4R100 (15.9 qts for 4x2 or 16.4 for 4x4). Granted, I think Mercon V is "backwards compatiable" with regular Mercon. I should clarify on the bottle.

 

[kosinar]

I looked at the bottle and I did use Mercon V. I was told that I should use 6.5 Qts. It looks like that is too much. Level is at least 3 inches above mark Could it cause my trouble if transmission is overfilled? Car does barely move regardless of rpm. I will drain it to proper level.

 

[ELVATO]

The amounts I stated above are for when the torque converter is emptied as well. If you just dropped the pan, then I think it should only be like 5 qts, though empty enough to bring it to level on the dipstick.

 

[kosinar]

Update

Transmission issue was caused by low fluid level. Engine hesitation was caused by clogged fuel filter. Truck is back to normal. Thanks to all for input. Now If I could just find the cure for one annoying electrical problem but I will post that in electronic forum.