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4.9 has no power at highway speeds

Discussion in 'Ford Trucks' started by Bucky Badger, Jan 13, 2002.

  1. Bucky Badger

    Bucky Badger Junior Member
    Messages: 19

    I've got an '89 F250 with an 4.9, 5 speed, 4x4...The thing has plenty of power in the lower gears but once I hit highway speed, it has no power...It struggles to go up medium grade hills or less in overdrive...I had an 88 F150 a couple years back, and that thing would go, go, go...same motor with a lighter 5 speed...

    I'm downshifting on hills that I shouldn't have to....it's been totally tuned up, I had the EGR valve replaced a few months ago, it was rusted shut, but that didn't solve the problem...

    Anyone have any ideas before I decide to drop any more cash at the dealer? It's got 130,000 miles and doesn't burn a drop of oil...

    Thanks guys!
  2. Randy Scott

    Randy Scott Senior Member
    Messages: 142

    Catalytic converter may be plugged. I had an '85 fullsize Blazer way back, and would slow to like 50 up hills on the freeway. Took the plug out of the converter and knocked all the beads out of it, ran like a champ after that. I think Fords in those days had that honeycomb style converter instead of beads like GM. You may have to buy a new one instead. Something to look into maybe.

    Geez, I didn't even notice you were from Wisconsin until I placed this response. Explains the Bucky Badger.
    Last edited: Jan 13, 2002
  3. 81pickup

    81pickup Junior Member
    Messages: 21

    My dad had a '95 F150 4x4 with the 4.9 and a 5 speed. when he first got it it only had 16k on it. It was great on the hills and never had to go lower than 4th gear. After he put about 100k on it it didn't do so well. I would say your problem is quite normal. As your engine gets older it will start to lose power. But I found that a bottle of injector cleaner made a huge difference in performance. Try dumping a bottle in everytime you do an oil change, or go and have the injectors removed and professionaly cleaned. Shouldn't cost you more than fifty bucks* ( Canadian... thats about what, 20 bucks US these days???:) ) Try that and let me know what happens.

    Good luck.
  4. Bucky Badger

    Bucky Badger Junior Member
    Messages: 19

    I think I may have a crack in the engine somewhere now as I'm losing coolant and can smell it in the exhaust....going to throw a 4.9 out of a '89 E150 in it...see how that does...I'll check the cats out when I pull the old motor...

    I usually pour a can of Seafoam into each tank every couple months....Stuff seems to a good job...

  5. Mike 97 SS

    Mike 97 SS Banned
    from U.S.A.
    Messages: 1,106

    Hmm, id guess clogged converter, bad gas filter, or worn timing chain. Id say the first 2 more so. When has the gas filter been changed last? If the converter is bolted to the front pipe using a flange, disconnect it, tie up the converter and take her out for a ride. It will be loud as hell, but if it has the power back, that tells you the converter was clogged since you are now bypassing it. When was the last time it had a tune up? Sometimes you cant overlook the little things. Are you sure the transmission isnt slipping in the higher gears not letting you go faster? I try to help on these forums, but its hard without seeing the car/truck or driving it for myself. I just dont want to send anyone on the wrong trail, but at the same time i think i like to help. :drinkup: Mike

    EDIT, just read your post about losing coolant. Id get that checked first, maybe the 2 problems haveto do with each other.
    Last edited: Dec 8, 2002
  6. Bucky Badger

    Bucky Badger Junior Member
    Messages: 19

    I changed the filter after I bought it a couple years ago...didn't do any good. There's no timing chain- the 4.9 is gear driven. I've got a 5 speed in it, and there's no clutch slippage, the only thing I haven't done is the cats because both of them are a one piece unit from the manifolds to a short 18" pipe...I will probably eliminate the cats completely...ya, I'm sure I'm breaking a few laws, but it isn't the first time....like when I put a 318 out of a '74 Duster into a '79 Dodge Power Wagon was illegal because I was putting a leaded engine into an unleaded chassis... but I was "lucky" they didn't "enforce" the laws...so the emissions people said...

    Anyhow, I just think the engine is tired...not worn out, just tired..it used to be a farmer's truck..I think he beat the snot out of it and didn't put anything into...not even sure he changed the oil in it..

    I did a compression check on it a while back and all the cylinders came out within specs. Now that it is burning coolant, I've decided instead of screwing around and pulling the motor, tearing it down and having the head and block checked for cracks, It'll just be easier to find another engine and drop it in...It's odd, because it doesn't seem to be burning it constantly...if I drive it and warm it up, stop, shut it off...then come out a bit later and start it while it's still warm, then you can really smell the antifreeze being burned...then it clears up.

    I'm picking up an engine on Thursday...The truck isn't worth sticking that much money into, it is a plow truck...a junk yard motor is cheaper than a rebuild...as long as it holds together for a couple more years, I'll be happy.

    Thanks for the ideas!
  7. SDlawndawg

    SDlawndawg Senior Member
    Messages: 139

    I'm surprised you are having trouble with a trusty engine like the inline 6. I'v owned a couple f-150's with the 6 and never had a major problem even in excess of 200,000 miles. You shouldn't have a problem finding a reliable replacement.

    I heard somewhere UPS bought the patend or rights or whatever to build that same motor and put it in their trucks.
  8. Bucky Badger

    Bucky Badger Junior Member
    Messages: 19

    Ya, I had an 88 F150 with a 300 in it and never had problems with the engine...with that one it was the electrical system that gave me fits.

    I had it in for an alignment last week and the guys at the garage didn't seem to be too surprised...it used to be a Ford dealership till Ford closed closed 'em up...

    Something's been wrong with it from day one, but it's ran well enough to do the trick...I had it in the dealer once, they replaced the EGR valve and thought that was the prob...it wasn't...

    Now I just gotta find a nice warm garage to do the swap...