Rough running V10 with 100,000 miles...
 

My 99 Ford F250 Xcab 4X4 long box V10 just turned 100,000 miles. I've never had any engine problems until now. I was pulling my boat home from a service appt. the other day and noticed a loss of power and shaking/vibration when accelerating from a slow speed. I noticed that when towing with the overdrive off, the truck would shake when accelerating slowly from a slow speed. It also seems to be off on the power. I did some checking and discovered my 4 year old 3" exhaust with Magnaflow muffler appeared rusted and plugged. I could see and feel exhaust coming back out of the intake port. I thought this might be the culprit, so I had an exhaust shop put in a cat back 4" system with a sweet proflow muffler. The problem was still there. I think it's been at least 60,000 miles since it's had plugs...could a bad plug or two be causing this? The check engine light hasn't come on which I would think it would come on if it was misfiring? It almost feels like the torque converter, but I'm just not sure. I'm out of town right now for business, but I'm planning on replacing the plugs when I get back to see if that will fix it. Any thoughts on this??

I'd place my bet on a missfire, if you can get a code reader or head out to auto zone for a free scan. Most likely a c.o.p or spark plug would be the cause of your problem

best of luck:)
Skoda

C.O.P. died, sometimes they work when not under load then you give it some pedal and it starts missing. Have fun finding out which one it is, computer won't tell you which one it is until it totally dies. I'm still waiting on one that is partially dead form 2 weeks ago.

Check for codes to see if you have a bad coil. For some reason they do not always trip the check engine light. If not, at 100k, I can suggest replacing the spark plugs along with the coil boots (which come with the center conductor "spring"). While you are replacing the "spring" check the secondary terminal in the coil. I found a couple of these corroded and cleaned them. Some of the boots were soft and spongy so I suspect their insulation effect was minimal. After the above, the roughness and intemittent miss was gone. I've replaced my plugs at 50k intervals and noticed a significant improvement both times. I don't want to imagine what it would run like with 100k on the plugs.

Lou Manglass

mine did the same thing i just changed the plugs i was just over 100.000 miles things r fine now

Just replaced my 7th COP @ 192,700. It's a good idea to change all the boots at about 100,000 since the factory ones take some abuse from heat and other factors IMHO... DO NOT GET AUTOZONE COP's those things are junk. I hate re-replacing poor quality components. NAPA has about the best ones I've purchased so far. I've had 2 aftermarket ones fail just because they were cheap. the napa ones are constructed better just at first glance. $46.99. Auto Parts Fast at RockAuto has plug boots for $11.99 a set and they are good quality graphite-silicone from what they look like to me.

how about the cop's on ebay that give you a 2yr warranty?

anyone have any experience with them?

thanx

misfiring
 

When my V10 misfires the Idiot light (check engine light) does not light up. Both times it never lit up.

:confused:

I am willing to bet that you need new plugs and cops

Don't do that, you'll be throwing away money. Buy 1 COP. Put it on whatever cyl. you want to start from. If it doesn't fix it, (use the one you took off, since you know that the COP you removed is good) move that one to the next cyl. and so on, and so on until the problem goes away. Easier than moving the new one to each place saving 1 step in a two step process.

The CEL won't light unless the COP totally fails, intermittent misses are not enough for it to throw a code.

I am new and have posted 2 replies and 1 new thread due to the wealth of info in this forum. You guys are great for the nuubs. I am having a very slight miss on my V10. Thought about changing the plugs and boots all the way around. Would rather replace all at one time then one ten times. My truck is at 140,000, but I am nervous due to the blow out a spark plug thing. If everything is torqued properly, will I have any trouble and am I heading down the right path?

Thanks

I advise to change all the plugs and boots if you want to but don't waste your money replacing all the Coil Over Plug components. Do like I said above and replace one and move it around until it goes away.

Well, I personally went to autozone, had them plug in their reader, and in my instance there was 2 bad cops. No guess work, knew which ones, changed them, fixed missing, easiest thing in the world.