97' stock F150, 4.2. Haven't done any troubleshooting yet but will begin tomorrow with a compression test. Losing power and need to downshift going up small hills on the interstate at 70 to 75 mph. Other symptoms which may be clues are: odd put-put sound from exhaust at idle; continuous small amount of coolant loss. Oil and coolant remain clean. The engine runs smoothly other than the recent power issue. Does this sound like a head gasket as some have suggested or a clogged converter, maybe carbon build up? Concerned it may be a valve due to the exhaust sound. This truck does mostly highway travel, regular oil changes, moderately well taken care of.
Thanks for any help.

 

check the cats-phil

 

yup a clogged cat can cause those symptoms. grab a rubber mallet and tap the cat if you hear a rattle that the problem.

 

cats usually make a nasty ticking sound when they go. id look into a stuck valve or bad injectors. how long has it been since you changed the spark plugs and wires?

 

Have you run a code check yet? If not, I'd do so before opening the hood.
How many miles are on the vehicle? Last time o2 sensors replaced? Last time fuel filter replaced? Fuel pressure is how much? And like Chief asked, how long since last plug change?

SL

 

Symptons describe a clogged converter, not ignition or fuel...

 

Ive got a 97 4.6L with some what of the same issue but mine loses power when im in 4th but mostly 5th gear. I dont have the noise or anything else coming from the exhaust just the power lose when going up hills and such in gear. I would also luv any help that can be given.

 

if i understand you right, you're trying to climb hills in overdrive? of course you're going to lose power and slow down, try downshifting to 4th or 3rd gear.

 

No ur correct and I understand that, but its like when I want to give her gas even on a straight road and a slight alittle incline its if she doesnt want to go even if I push down on the gas peddle. She just loses speed and has no pickup.

 

You might have a small head gasket leak if you are losing a small amount of coolant. You shouldn't lose any. Check the color of the oil. I know you said it was "clean", however if it looks milky you better get her fixed fast. Other wise check the cats. YOu should be able to stay in 5th gear on the freeway no matter what.