Hey all! I have a 1996 F150 XL 2WD 4.9l with the E4OD and have been having an issue with power loss that I can't quite figure out. I feel like the truck struggles to get going but once it gets over 20mph or so it "takes off" as much as the 4.9l can. I can't say the truck never had some issues, it is just much more prevalent now. If I were to start from a stop at the bottom of a long hill, I am seriously unsure it could make it up. If I was already going 25mph, I wouldn't be worried at all. I initially thought it could be a transmission issue but the fact the power seems to pick up at the top of 1st gear threw me off. Also, when I put it in reverse, the truck almost feels like it wants to stall out. The power in reverse is lacking as well. I wasn't able to reverse up a long, steep driveway before and it won't pull one tire over the curb when I back into my driveway. There have been a few times when the truck would randomly drop into "neutral" while driving like it misses a shift into OD or something. I have to pull over, put it in park, and then it's fine. There are times where it would shift hard into 2nd as well and go into limp mode, although I haven't had that happen since I changed the trans fluid and filter. The magnet in the pan didn't have any metal chunks on it, only what you would expect which also makes me question if the trans is the problem. Could it be the torque converter or engine? Any insight on what to check next would be greatly appreciated, thanks!

 

Not knowing the history of your truck, I would start with the engine. Scan for codes first. If anything comes up, solve them before you go on. A poor running engine can make anything seem like it's a problem, I would start there. There are lots of things that can make your engine run bad. If you are good at diagnostics, start with your sensors and control. Make sure their with in levels. I also am not a believer in "if it ain't broke, don't fix it". Anything that contains an electrical current is degrading from day one. That is not to say it doesn't work, just maybe not up to spec. I am not the best at diagnosing and have a tendency to replace parts just because they have been on the truck for a long time. I've replace most all of the sensors and controllers that I can get to. I had no reason to replace my EGR, but I did and I think my engine now runs a little better.The Idle Air Control, the Intake Air Temperature sensor, clean the throttle body, the Throttle Position Sensor, Oxygen Sensors, the MAP and MAF. Check fuel pressure at the rail. Poorly running fuel pumps can make the whole truck seem bad. I have an Actron OBDII Autoscanner that lets me see live data as I drive. And if you haven't changed your plugs, wires, cap recently, check timing, might as well do that. We had a work van that could barely get out of its own way because it was in desperate need of a tune up. Injector cleaner could help also if you haven't done that either. I've also Seafoamed my vacuum lines. Not sure if that is a popular thing.

Anyway, the whole point is to make sure your engine is running the best it can before you dive into a transmission. Unless you know how to fix one, there is nothing cheap about that. And bad transmissions won't destroy your engine unless something weird happens. It will just stop moving your truck.

 

Thanks for the advice, I'll definitely look more into the engine first. I don't really know much of the history of the engine myself. The truck has over 280k on the odometer and I know the previous owner replaced the engine with a junkyard one with 100k+ on it. Codes come and go, I generally try to address those as best I can when they come up. Currently, it has a P1507 but that's from a new idle air control valve I tried in hopes it would help with the problem. Some others that pop up semi-frequently are P0500, P1443, P1409, P0385 which I haven't solved yet. I only drive the truck a couple thousand miles a year if that so when I try a fix and clear the codes, they don't come back quickly.