Here's the problem. I have an F-150 V6 1997 with 80,000 miles it has an intermittent engine shake, rough idle??, this is baffling when I take it to the Ford it acts normal, back on the road, and the rough idle starts. Primarily it hapens at the end of a fast acceleration or when I come off an exit ramp. All filters, plugs, were changed at the big 75K party. Any thoughts or suggestions

 

This mignt help you or it might not. All of the 97-new V6's have whats called a ballance shaft. It is a metal(steel, iron, ect..) shaft that is almost as long as the engine is front to back. It sits above the camshaft in the block and is run off the camshart in the oppisite direction of the engine. The reason for this is the 4.2 is a very unballanced engine, and a ballance shaft is the only way to keep the engine from shaking apart at an idle. If the shaft is off by a tooth or so it could cause an idle that is not very smooth, but since you said that it is intermittent it might be questionable if that is your problem or not. Even though it's probably not the ballance shaft I would bring that up to your dealer or tech and find out what they think on it. Hope this helps.

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99 F-150 4.2L
True duals W/Magnaflows
Jacobs Ignition
K&N filtercharger
Custom programed chip
throttle body spacer
ported&polished throttle body
ported mass air flow sensor
Black Magic electric fan

 

a 1997 with 80,000 miles, and shaking at idle
hmmmmmmm.Thats a lot of miles for a 97. Any way, might be a computer problem- one of the parts is going out- maybe if it goes all the way out you will know what it is. seriously though beats me.How did you rack up so many miles in three years?I had a 98 that I thought I drove alot traded it off this march and it only had 35,000.

 

Have you switched to a different grade or brand of fuel? I had the same problem and found that using a different fuel solved it. I used to use Exxon 87 octane. I switched to using Mobil fuel and the problem went away. I also tried using the Chevron Techron injector cleaner on the first tankful which may have helped out too!

 

Did you replace the wires? I didn't see that listed. The problem you describe sounds like a classic wire issue. Also, the 97 F150 requires DOUBLE platinum plugs. If you did not replace them with the DP's, you'll have significant spark issues. The spark is so hot it burns up all other plugs. I've seen it happen, not B.S.

 

Thanks, for the comments. I am going to start with the Fuel, Since I fill up twice a week this should be easy to do. I'll keep you posted on the out come. By the way the 80K mile were hard highway miles for work. In three years I have been to more cities than a rolling stones concert tour.

 

2far2go

I have the same problems with my truck. Ford has pretty much told me (in not so many words) too bad. I have no xtended warranty so I now just deal w/it. Here is the link to the archives that I origianally posted....Good luck

https://www.f150online.com/f150board...ML/000064.html

Later...Bigmike

P.S. If the dealer happens to read the code as it happens please post the results.
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Tan 97 F150, 2wd, Supercab, Tinted windows, Piaa's, 4.2/auto, Pwr everything 4/5 drop. Billet grill, Clear corners, Leather steering wheel cover, Pioneer CD head unit w/steering wheel remote, Alpine amp, Clifford alarm, custom box with a 10” Kicker pro comp sub.

Future mods: Thinking hard about 4-link rear & air on all corners, Shaved emblems, Rear roll pan




[This message has been edited by big.mike (edited 07-31-2000).]

 

hey I've got that too! except every once in a while a shutter will go through the truck hard enough to rattle your teeth out.
it has only died once.
got 72,600 miles on a 97 auto. things got a little better after a new fuel filter. now i've got 6 bosch platinum 4's waiting to be installed. then i'll continue the fuel treatment routine to clean out the fuel injectors. i think its a fuel system related problem.
i don't think its computer related b/c a nice man hooked up a comp on my truck at the texas heatwave and nothing ran bad on that particular area.

 

Concerning the shaking at Idle. Ijust purchase a 2000 F-150 and with less than 200 miles, it started to shake mainly when in Drive and stopped only. The local dealer could not figure out the problem, they contacted Ford's Hot Line for advice. The Hot Line told the dealer to replace engine mounts and re-align exhaust system, it did not work. The Hot Line then advised to do a vibration analysis at Idle 700 RPMS, conclusion: "Unknown vibration". Finally the Hot Line advice the dealer that future Idle stratigy will be available to increase Idle efficiency at 750 - 775 RPMS. In other words, they will reprogram my trucks computer when the new program is available, they claim to be waiting for EPA approval. I now have 1,600 miles on my still shaking truck.

 

plug wires gets my vote, , especially if it started after you changed the plugs, one of the terminals may have gotten sprung when you were pulling the wires off, or maybe the conductor has pulled out partially and is causing this intermittent problem

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BigBunnell

98 F150 4X4 XLT flareside V6 5sp K&N Flowmaster and some other goodies

 

I might be able to help you... I have a 98 STX V6 with about 78,000miles on it and I have had the same problem (Yeah I drive it a lot) I tried everything from plugs to fuel filters to wires and everything imagineable except one simple little thing that we take for granted. What I came up with might be surprising but it has seemed to fix mine. THE DAMN EGR VALVE!!! The computer does not seem to pick up on it. It was sticking open just a little at idle causing it to run rough. So pull your EGR valve off try to clean it as best you can and put it back on to see if it helps. You should probably go to the Ford house first and pick up a gasket for about $2.00.. I am planning on replacing my EGR all together when I have time. It runs about 50 bucks. I have a feeling it will solve your problems... Let me know how things come out. STXMAN

 

This is EXACTLY the same problem I have(as big.mike has described in his archival post). Has anyone been able to identify the cause yet? I'm just wondering if anyone has breaking news at this point.

 

I had the same problem on my 98 5.4 f-150. It was bad vacuum lines. One to the pvc valve and the other to the evap. canister.

 

wow how old is this thread? I have a 99 f150 with 255000 miles on it...same problem. I replaced the plugs (i hadnt read this forum yet..so it got bosch platinums instead of motorcraft) factory replacement wires, and a new coil pack. It's still missing at idle. Im also heating up going up long inclines as well. I'm thinking its the egr valve too, at least i hope thats what it is. If this doesn't work im going to put motorcraft plugs back in it.

 

Regardless if this works or not get rid of those Bosch plugs. They suck in these motors. If you doubt me just do a search and see how many ppl hate them. I put in a set in my truck. It ran so rough I thought it was going to shake apart. Put the old plugs back in, ran smooth. Even gapped properly they just don't work well in these motors 99.99% of the time.