Ford F-150 (2004-2008) :: Bucks / Jerks In OD Around 40 MPH When Accelerating

Truck is 08' with 5.4, 3.55 gears, auto trans. 84k miles. Recently purchased from the TSA fleet trucks, so I have no clue what PM procedures were done prior to me getting it.

I noticed the following: when I get the truck into OD and then slowly decelerate (meaning I let it coast and im not braking) to about 40mph then get on the gas (normal acceleration) the truck bucks hard almost like when your spinning wheels on snow or ice and put the truck in 4wd and the front rear locks. or a limited slip rear that catches when one wheel is spinning.

if I accelerate hard the truck pushes thru it and doesn't buck as bad. I have searched this out and there are several threads about it that describe just about exactly what im talking about, the following have been brought up as possible problems:

1) bad spark plug/s and or coil/s
this seems to be the most common answer to the possible problem.
2)broke valve spring
3) bad torque convertor

So at 84k miles im thinking replacing the spark plugs would be fine to do as a PM. So coils.............should I just go ahead and replace them as well? I found them (motorcraft). does that seem right?

As far as spark plugs, I have already read the horror stories on the 04-08's breaking the plug in the head. I have also read that before 10/07 was the trucks that had the issue. my build date is 02/08. am I good to go with normal removal of the plugs? the best method I have read for removing them is spray carb cleaner down the hole and let it soak overnight and then the next day drive the truck get it nice and hot and remove them right after you park it,,,,

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Ford F-150 - 1997-2003 :: 1994 - Under Quick Acceleration Bucks Violently And Die?

E 350 with a 5.8 drive ability headache 94 E 350 with a 5.8. about 1/2 throttle or under quick acceleration it bucks violently and will die if you don't let up on the throttle. This all started when it was run out of fuel. I found the condenser wire was shorted to its own body. Causing the PCM fuse to blow. I have since replaced the condenser. Same problem exists. I have replaced the map sensor with a known good one, same with the O2 sensor.

The TPS is in range and goes through its range smoothly (this was done on my scanner) Also replaced the fuel pump either due to the fuse blowing or running it out of fuel it wasn't working. Fuel pressure is 30 to 32 psi. I've checked the EGR for leaks and proper operation. I have noticed its very hard to start when its cold. Someone has had problems with it in the past as cat is new and i have noticed some things have been removed or replaced recently. The van was just purchased a few weeks ago by my buddy.

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Ford F-150 - 1997-2003 :: Truck Bucks Wildly Either In 1st Or Reverse When Feather The Clutch

97 F150 4.9 200xxx 5 Speed .....

I'm having an issue with my truck. It only seems to happen during warm 80+ weather. In the mornings, and during colder weather, the truck runs perfectly.

My problem is; Every time I go to get going and feather the clutch, either in 1st or reverse, my truck bucks wildly.

I changed the plug wires about 500 miles ago, and am about 4000 miles on a rebuilt engine (plugs as well) and new clutch/resurfaced flywheel. The clutch reservoir is full and I haven't noticed any leaks. There have been no codes thrown.

Could it be a possible fuel problem? I think I changed the fuel filter about 7k-10k miles ago.

I was also wondering if the Gotts mod could be causing it. I did the mod during the winter time, and this is my first summer with it on. My air filter is fine.

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Ford F-150 - 1997-2003 :: Engine Only Bucks / Stumbles Intermittently And Not At Idle Or At Harder Acceleration

2001-F150 5.4 Eng. bucking/stumble. I think my problem is slightly different than what I am reading about. Here is what I get (125k miles):

* Engine only bucks/stumbles intermittently and not at idle or at harder acceleration (this bucking is really harsh and makes the truck feel like a learner trying to drive a manual transmission and it is jumping down the street). The engine stumble is not a regular timing such as a cylinder going out and staying out for a period of time. It is quite a random pattern to the jumping

* Originally thought it was humidity related, but now I realize it happens in any climate

* No stumble in neutral at any rpm... only at a stop if I put it in a power brake load.

* When the stumble shows up, it seems like the throttle is around 10-25% (my best guess)

* Sometimes goes days without issue, but sometimes every ride and virtually every acceleration.

* Normally no stumbling at highway speeds, unless going up a hill.

* Every time it stumbles, it can be eliminated by either backing off on the accelerator some, or hitting the accelerator harder.

* No engine codes or CEL has ever come on

* Fuel mileage appears to be the same before and after the trouble started

Here is what I have done to try to correct it:

-> Fuel related (bad gas)... tried to run the tank as close to empty and fill it with fuel from different stations... when this didn't work, I have added HEET to it to dry up any water in tank.

-> Fuel delivery... replaced the fuel filter... seemed to work for one day, but then the gremlins came back.

-> Fuel delivery... ran multiple injector cleaners through tanks of gas.

-> Intake... replaced the filter.

-> Electrical... I don't believe this is related, but my battery died... parts store tested the system and stated the alternator was bad... replaced it, and took the old one to the parts store for bench testing and it was 100% OK... even thought the old showed OK, I left in the new one as a precaution. Only other item was a set of plug changes around 30k miles ago... I think I put in the super duper Bosch plugs with a lifetime warranty.

Current thinking and items I don't understand:

A) The bucking is so severe, it appears to be a random harsh loss of either fuel or ignition. A component that has failed electrically should give me a fault code with this level of severity. No trouble codes or indicators to electrically sense this disturbance...

B) For the fuel path, the most likely item is bad gas and I emptied my tank by running it as close to empty as possible and then used different gas and HEET to eliminate water. THIS MIGHT STILL BE THE CAUSE???

C) Another one for the fuel path is an intermittent fuel pump electrical connection or a weak pump from a pressure point. But if this is the cause, then why does it dissappear upon harder acceleration?

D) One last fuel thought is injectors... perhaps one or more have a range of delivery that they don't work properly... but this doesn't make much sense as at idle and harder accels are fine

E) From an ignition standpoint, perhaps I have failing COP's. I have not just gone out an replaced them due to my limited budget and the difficulty I read about changing them. Again, if one of these is failing in an either open or short condition, the computer should set a code for a misfire for the related cylinders. I get nothing. Hence my hesitation in making this change so far.

One thing i don't understand from the various posts is that the cops can fail under loading. what makes this happen as electrically, i don't think they can detect a load or not? it is hard for me to also understand why my truck would allow me to back off on the throttle or hit it harder and the issue disappears.

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Sierra :: 2000 5.3 Sierra Suddenly Overheated In Cold Weather Then Fine

A friend of mine has had this 2000 Sierra since new. It has just over 100K and never had any cooling issues before. Last week when it was about 10 below zero she drove it home and it overheated and pumped a couple quarts of antifreeze overboard.

She refilled it the next day and it was fine but got it looked at by a local independent mechanic. I had told her that it was likely a sticky thermostat and it ought to be changed out anyways due to its age. The mechanic thought I was wrong and that she had driven it off to quickly in the super cold weather.

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GMC - Sierra :: 1997 Won't Go Into Park / Lever On Trans Stops At Neutral

My 1997 3500 shifts down normally through all gears but when I put it into park the lever on the trans stops at neutral I can then click the lever forward to rev.and park.

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Sierra :: 1997 - High Pitched Whistling Sound Around Throttle Body

97 Sierra K1500, 5.7 liter. High pitched whistling sound underhood in the vicinity of the throttle body. Starts after truck warms up and quiets down when accelerating. I've wiggled hoses, disconnected what I could without stalling engine, checked air lines into throttle body, checked air filter, etc. Sound does not change when I apply brakes so I don't think it's related to master cylinder. The only time it changes is when I accelerate, then only gets quiet until I come back to steady speed.

Truck has 85,000, runs great. No codes.

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Passat (B5) :: 1997 - When Accelerating Car Would Die Sometimes

Just have a few things wrong with my Passat 1.9 tdi... When I am accelerating sometimes the car would die, almost as if the turbo has just cut out and the car struggles to pull along around 40mph, once i pull over, turn the engine off and start up again its fine!... It could go fine for a week then do it 5 days in a row it just seems a bit temperamental and happens at the worst of times!

Sometimes half way up a hill and the car travels up around an embarrassing 20/30mph until i get on a flat again, other times would be pulling away from lights and id be quick one minute then its gone!... just seems to be when i need a bit more power, it gives me the opposite! [URL] ....

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Passat (B5) :: 1997 - Heat Only Works While Accelerating

97 passat vr6. I only get warm air from the vents when I'm accelerating. As soon as I come to a stop it starts blowing cold air. Does this mean there is air in the system? If so how do I bleed it out?

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Ford - Explorer :: 1997 - Started To Bog Down While Accelerating?

My 97 Explorer 4.0 SOHC has started to bog down when I press the accelerator. It feels like their is interference with the exhaust. I has a new muffler and there are no holes in the exhaust system. When I stop at a light or in traffic, it will stall. I have to keep the RPMs at 1000 while holding the brake. There is no check engine light on. Where I should begin to look?

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Grand AM :: 1997 2.4l - Oil Leak / Knocking Noise While Accelerating

My Grand Am has a bad oil leak (timing chain gasket) recently overheating and now makes a knocking noise while accelerating, especially up hills - which stinks as I live in Pennsylvania! I am pulling it apart - camshaft covers (both - its a dohc) and timing chain cover. How do I determine if its a main bearing or bent lifter rod or bad rockers?

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Passat - Volkswagen :: 1997 - Feels Like Downshifting Even When Not Accelerating?

When I'm driving, steady mph, my car feels as if I've just downshifted, or that my foot slipped off the gas pedal. When this happens I've noticed that the tachometer drops down from say 20 - 30 to 10 or less! But just momentarily. It happens to a warm or cold engine. It's going to give me a whiplash! I've brought it to my VW dealer. They put it on the computer, and no problem comes up! No lights on my dashboard are on either. This problem is really annoying.

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Ford F-150 - 1997-2003 :: Missed A Shift Into 3rd While Accelerating

Ive got a 2000 4x4 F-150 with a 4.6 and a 4r70w. The transmission and transfercase were replaced by the P.O aprox 2,000 miles before i bought it..

i was driving it today, and while accelerating it missed a shift into 3rd, then nothing no forward or reverse, i sat and messed with the gears for a while then suddenly it shifted into 1st now it drives with a slight resistance, revs up to about 3K before shifting and shifts HARD up and down, and i cannot get over 40 mph its at about 2800 rpms and feels like im hitting a rev limiter wont shift again and wont accelerate anymore..

When at that speed I hit the OD off and it downshifts so i think i still have od?

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Ford F-150 - 1997-2003 :: Bogs Down And Stumbles When Accelerating

2002 F-150 4.2L. About a year ago, it threw the P0171 and 0174 codes up. After replacing all the simple stuff, I bit the bullet and replaced the lower intake gasket as well as the upper intake gaskets. Buttoned it all up, reset the codes and we were back in business. No issues, truck ran good. About 6-8 months later, the check engine light came back on, I check it and it was that pesky set of codes again, 0171 and 0174.

It still ran fine, but the codes were there, so I just drove it for a while (it's a company truck that doesn't get driven that much).

A couple of weeks ago while driving it, it acted very sluggish. You could mash the accelerator and it would just very slowly run up the speed. It never hesitated or missed, it just got very very sluggish. Checked the codes, no additional codes.

Then it began to stumble when you mashed the gas.

I put new plugs (old one's looked great, other than a huge gap), new wires, new coil pack and started it. Pushed the gas pedal, it just dies.

I look for obvious vacuum leaks and replace a couple of elbows for the PCV and it seems to run a little better. Enough so that I can drive it, but still not running right.

I ordered all the intake gaskets and new isolator bolts and spend Saturday pulling that apart. I didn't do the lower intake because the upper intake gaskets looked so good, I just don't believe this is a intake gasket problem. None the less, I installed the new gaskets on the plenum and upper intake, new isolator bolts, replaced a couple pieces of vacuum hose that looked cracked, started it back up, it ran as smooth as silk.

Convinced I had it fixed, I went for a test drive. Idling, it is as smooth as you could ask for. Pull up to a stop sign, wait, step on the gas and it chokes. Just stumbles and you can hear it almost backfiring and pushing air back through the system.

I've put new PCV, new EGR, new vacuum lines in several places, new upper intake gaskets, new plenum gaskets, new isolator bolts, and even new o-rings on the injectors, and I'm still getting the 0171 and 0174 codes.

With the diagnostics on, I can see voltage varying on all O2 sensors, so I assume they are working (none of them are reading 0 volts). It doesn't throw any other code up, other than the 0171 and 0174.

At this point I feel like I'm replaced every single thing ever mentioned in any 0171 and 0174 thread on the internet. Where to go next? 1 more point, if you very slowly push the gas, it runs fine, but any pressure on it, it bogs down and just stumbles.

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Ford F-150 - 1997-2003 :: Transmission Hesitating While Accelerating?

Recently, my truck has started rolling back from a stop when accelerating. There seems to be a hesitation between when I depress the throttle and the transmission engaging. It doesn't clunk, just delays. Been doing it for a few weeks, but is now getting worse. Today, the symptoms are similar but more pronounced. When driving there doesn't seem to be an issue, just moving out from a stop.

Checked the fluid idling in park, level was good, fluid looks great, was changed by a shop 6 months ago. Is my 319,000km trans on its way out?

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Ford F-150 - 1997-2003 :: Shake / Shudder When Accelerating Around 45 - 55 MPH

My trucks been doing something weird. When accelerating around 45-55 mph, a couple seconds after it shifts to 3rd, it does a weird type off shake/shudder. Feels like I hit a small bump in the road. Also when coming out of a cruise to accelerate, it will Make a very violent clunk and then speed up. I'm thinking it's a problem with my torque converter but my mechanic says transmission and my buddy says rear end lol. I dropped the pan and there was some shavings but nothing huge and it was the first time it was ever dropped. After 90k miles.

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Ford F-150 - 1997-2003 :: Clunk When Accelerating And At Takeoff

So I have an issue with my 03 f150, Basically It clunks in various scenarios such as Accelerating also occurs take off and general breaking/slowing down but not really when stopping. December when it was cold and I was decelerating (not on the break just coasting) it feels like i was driving on the shoulder.

It does it much more in cold weather. Just had the truck out getting a little rough with it for 5 or so hours today and 0 issues with it.

I was thinking it was a slip yoke issue that I hear allot of trucks have the issue but I was at the dealership today and both guys and a mechanic sitting there were like "never had that issue on an 03 f150, might be your back end." They also stated the clunking would always occur and be more prominent when breaking which its not.

I am certain its not the transmission its not occurring with any shift point. Kind of hard to do it if its hard to reproduce in the heat.

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Ford F-150 - 1997-2003 :: Humming Noise While Accelerating?

Noticed the other day when I was driving on the highway my truck started humming when I was accelerating past 30. From a dead stop to 30 its fine, but after it starts humming. Its only when I have my foot on the pedal. When I let off, it stops. The sound is coming from the rear/under.

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Ford F-150 - 1997-2003 :: 2001 - Jerking While Accelerating Between 40 - 60 MPH?

Just purchased a 2001 Ford F150 super crew lariat v8 4.6/5.4 2v OAD at 156k miles, iv had no problems with it until I drove over the pass and after 2hours of driving my truck started to jerk when I accelerate between about 40-60mph. I don't experience any other problems over 60 it runs smoothly and in town under 40 it also runs smoothly, no check engine light. The next day is still continues to make a jerking motion, which feels like from the rear.

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