3rd gear surging
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Mountain Pass
Joined: Sep 2004
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3rd gear surging
While driving today about half way through my 60-70mile long trip i noticed the truck surging when under load in 3rd gear at above 3700RPMs (climbing hills). I beleive i even heard the belt slide during one of the surging periods. I sometimes even think i can smell something burning but im not sure what. That even makes me take the clutch into consideration even though its only about 3000miles old. any ideas? I not sure how to describe the problem so i had no i dea what to search under. My truck is a '99 B3000 4x4 manual.
Thanks guys
Thanks guys
Logistics Pro
Joined: Jan 2002
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From: suburban atlanta
Spark plug misfire under load. Check the plugs. Also check the wires. One time had wires that failed under load. Could see a light show after dark, and had misfire when cold and damp. Other than that, were fine, except that it would just start to miss going down the road. Went away when I disconnected the EGR. New EGR, same problem. Finally say the light show, and got new wires. Ran like new.
If the clutch will hold when your press the gas pedal to the floor while driving in 3rd, then it is not the clutch. If the rpms flare doing that, the clutch may be slipping.
tom
If the clutch will hold when your press the gas pedal to the floor while driving in 3rd, then it is not the clutch. If the rpms flare doing that, the clutch may be slipping.
tom
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Mountain Pass
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yea i didnt see the rpms jump when it would jerk so i didnt think it was the clutch. it almost did seem like a misfire but i have never experienced it b4 so im not sure. I just changed my plugs and wires about 3000miles ago as well so that was one of the last things i considered. Im not getting a CEL so the computer isnt noticing it.
Thanks, sorry i cant be more descriptive. the only time i can get the problem to happen is find a hill to climb in 3rd at about 55mph
Thanks, sorry i cant be more descriptive. the only time i can get the problem to happen is find a hill to climb in 3rd at about 55mph
Logistics Pro
Joined: Jan 2002
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From: suburban atlanta
I'd check the plug gap. If it is too large, you can get misfire under heavy load, such as climbing a long hill. Or you could be getting crossfire where one plug wire firing can cause another plug to fire, or the original one to misfire.
tom
tom
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Joined: Feb 2003
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From: Eastern WA
The fact that you have a surge condition at higher RPM's makes me wonder when the fuel filter was last replaced. Also, have you checked fuel pressure? Problems with a bad plug wire usually first surface as a misfire on a COLD engine that will go away once it warms up. What's happening is that the carbon fibers at the center of the wire are burning due to a break, the gap in the region of the break is increasing, thus over time the misfire will be noticeable on a warm engine. It's harder to fire a cold spark plug than it is to fire a warm one; ditto for the gap in the plug wire. Finally, and it's not common anymore due to heavy gauge insulation on plug wires, you might see arcing.
Last edited by CowboyBilly9Mile; Feb 20, 2006 at 01:55 PM.
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Mountain Pass
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I changed my fuel filter maybe 10000miles ago and like i said earlier the plugs and wires are all new. like i said it only started happening after driving for 30-40 miles only climbing hills in 3rd above 35-3700 RPM.
Thanks guys.
Thanks guys.
Post Fiend
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From: Eastern WA
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Post Fiend
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I would also tend to think it's a misfire under load.
Something else to keep in mind:
https://www.ford-trucks.com/forums/s...77&postcount=5
Something else to keep in mind:
https://www.ford-trucks.com/forums/s...77&postcount=5
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Mountain Pass
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would "squeeking" (best way i can describe it) accompany a missfire? I started noticing a noise when the jerking happens. its hard to pinpoint and i wanna say it sounds metalic but im not completey sure. maybe i can get some1 to lie on my hood while i make it happen lol. no but seriously its a really strange deal. i have no idea at all as to what it might be
Post Fiend
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From: Connecticut
When this happens, is the A/C compressor on? Remember that the compresser runs in all modes except "Vent", "Floor", and "Off". If the bearings are going bad, that can cause the A/C pulley to occasionally sieze, causing the engine to jerk and to make a squeaking sound due to the belt slipping.
Another thing that comes to mind is the camshaft synchronizer. When they go bad they can squeak.
Another thing that comes to mind is the camshaft synchronizer. When they go bad they can squeak.
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Mountain Pass
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no A/C compressor is not running. i have had been noticing some squeeking half the time when i start my truck so maybe my compressor bearing is going bad. but why would it only be in 3rd gear? or is it just that the circumstances are right when im in 3rd?
Post Fiend
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From: Connecticut
Originally Posted by Rockledge
Another thing that comes to mind is the camshaft synchronizer. When they go bad they can squeak.
https://www.ford-trucks.com/forums/s...hreadid=202004
New User
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do a belt and idler pulley, i have squeak on startup prety sure its the PS pump, if u hear a belt slipping then thats exactly what it mite be, mite, i dont know if 3rd really matters it prolly has something to do w/ rpm's and load
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