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04 V6 LS vibrates at idle, knocks under load and smells funny :)

branflake12branflake12 Posts: 5
edited June 2014 in Lincoln
My 04 LS with 48K (bought it at 33K in July 08) has always had a random "odor" that occurs only at low speed/stopped while it was warm. Kind of a burning odor, but not oil. I let it go, car has an extended warranty. Recetnly, the car has started vibrating at idle. Not "shaking" but like the whole car is a cell phone on vibrate mode. Only does it at idle, but its been getting more pronounced. I can stop it by keeping my foot on the brake and feathering in some throttle to get the RPMs up over about 900. It also knocks/rattles under load in the upper gears (or its never in 1st long enough for me to notice). Ford dealer called the knock "spark knock", said it wasnt covered under my extended warranty as a "maintainence issue" (note-fidelity warranties are not what they are cracked up to be) and wanted near a grand to replace all COP's and plugs and flush the fuel system. Didnt check on the smell and the vibrating started after that. Had a CEL flash at me once, got it checked as "misfire in #6 in the first 1000 RPMS" (which one is 6?)

I pulled the 3 easy coils and looked for scorch marks, cracks, oil in the wells-nothing. Didnt pull the plugs, might try that. Dont really want to pull the intake unless i have to.

Anythoughts on any of it? related?


  • akirbyakirby Posts: 8,030
    Was there any oil in the plug wells? If so change the valve cover gaskets and you'll probably need to change the COPs at some point anyway. That's the most likely culprit. At least you'd want to rule those out first.
  • they were actually all 3 clean. I was expecting oil, but they looked near new.
  • akirbyakirby Posts: 8,030
    I thought they had fixed the VC gaskets by the 2004 models but wasn't sure. That doesn't mean the COPs aren't going bad though.
  • Ill have to re-check them and take a hard look at the boot, maybe spark is getting thru there. Any chance its just a bad plug(s)? The COP's all looked fine to my untrained eye, but that doesnt mean much.
  • akirbyakirby Posts: 8,030
    They fail internally. They don't look bad and they may even test OK. You really have to test them individually under load. Plugs are a possibility and easy enough to change.
  • Would a bad coil(s) explain both the vibration AND the missing/chatter under load? I was considering a PCV valve at fault for the vibration. The burning smell however...I can't theorize on. Thanks!
  • akirbyakirby Posts: 8,030
    It will cause a misfire so yes. Wouldn't hurt to change the PCV valve though - if you have one - one of the engines doesn't use one but I'm not sure which one. Check the OM. I think the V8 doesn't use one.
  • toomanyfumestoomanyfumes S.E. Wisconsin Posts: 1,004
    Yeah the V6 has the PCV. I bet it's not the plugs, probably COPS.
    2012 Mustang Premium, 2013 Lincoln MKX Elite, 2007 Mitsubishi Outlander.
  • blustblust Posts: 5
    I had a misfire #6 spark plug, I replaced it.then # 5 had a misfire. I replaced all 6 cop's and spark plugs. still runs bad. the mechanic said it was the # 3 so he swithched the cop's and plugs around and it worked for a day...took it back and he said it was the cat. convertors. I replaced both passenger and drivers side and the FOUR 02 sensors upper and lower...he also replaced the fuel it shows a #2 misfire and he said he doesn't want to work on it any more and has done all he can do...any ideas?
  • akirbyakirby Posts: 8,030
    I'd say it almost has to be fuel delivery. Could be a bad fuel pump - the LS has 2.
  • What was going on with yours that you took it in?
  • blustblust Posts: 5
    the codes kept showing a misfire # 6 cop or spark plug. The #6 plug has been changed atleast three times. That's why I bought Six new cop's and spark plugs. Took it to a reputable shop and he charged me $245 to put them in...Drove great for one day then the cel came on and it was a #5 misfire. I pulled out the plug and unhooked the battery. hooked them back up and it was fine. the next day, I stopped to get gas and when I started driving the cel came on and went into limp mode. I took it back to the shop. The mechanic looked at it and said the #4 spark plug was misfiring so he switched around the cop's and plugs, said it fixed it and runs great.

    I left the shop again and on the way home it drove real rough, so I took it back. He said this time Might be the fuel filter and the catalytic converters. He changed the fuel filter, the passenger and driver side catalytic converters plus both upper and lower 02 sensors (FOUR total)...he called me and said the car is fixed and runs fine, but the cel is on and shows a #2 misfire. He said he's done all he can with my car, so good luck...I supplied all the parts, he just did all the labor...since they were my parts he didn't waranty anything. I spent $1400 total...With his parts and labor it would have cost me $2700...That's why I supplied the parts and risked the no waranty...any ideas???
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