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    Slight hesitation/shaking when motor is hot

    When I have been driving over an hour and the motor is well within the operating temp, I have noticed that right after gear changes (and 65-66mph), when I give it throttle, I feel kind of like slight stumbling/shaking/hesitating that goes away when you romp on it. Any idea what it could be? it's a 97 townie

    I am thinking maybe injectors?

    I did change the plugs and wires and air/fuel filter not too long ago
    I cleaned the MAF sensor
    She has a new intake (aluminum crossover)

    Anyone else go through this?
    "To Find yourself, you must first lose yourself"

    -1973 Volkswagen Bus Westy
    -1986 Honda Magna 700cc
    -1989 Lincoln Town car Signature Series
    -2011 Subaru Outback

    #2
    This is probably not the issue but has it had a tranny fluid change recently? Couldn't hurt.
    03 Marauder DPB, HS, 6disk, Organizer Mods> LED's in & Out, M&Z rear control arms, Oil deflector, U-Haul Trans Pan, Blue Fuzzy Dice
    02 SL500 Silver Arrow
    08 TC Signature Limited, HID's Mods>235/55-17 Z rated BFG G-Force Comp-2 A/S Plus, Addco 1" rear Sway, Posi Carrier, Compustar Remote Start, floor liners, trunk organizer, Two part Sun Visors, B&M Trans drain Plug, Winter=05 Mustang GT rims, Nokian Hakkapeliitta R-2 235/55-17
    12 Escape Limited V6 AWD, 225/65R17 Vredestein Quatrac Pro, Winter 235/70-16 Conti Viking Contact7 Mods>Beamtech LED headlight bulbs, Husky floor liners

    Comment


      #3
      could be crappy gas. I know with the original engine in my 93, it required mid grade (89) to run without pinging/hesitating after ethanol was put in the gas. The 2000 doesn't have that problem though... so YMMV.

      Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
      rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)
      Originally posted by gadget73
      ... and it should all work like magic and unicorns and stuff.
      Originally posted by dmccaig
      Overhead, some poor bastards are flying in airplanes.

      Comment


        #4
        Which car are we talking about here? I'm guessing the 97 since you mentioned MAF and aluminum crossover intake.

        How old is the fuel filter? They clog up a lot more than injectors go bad. The original ones on my Mark VII were replaced at 230k, and the only symptom was a slightly rough idle. It ran just fine at anything above idle. Even if its recent, I'd change it because its probably the cheapest fuel system part to replace. Dump it out, that'll tell you if there is a reasonable chance that you have shit fuel or garbage in the injectors.
        86 Lincoln Town Car (Galactica).
        5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley

        91 Lincoln Mark VII LSC grandpa spec white and cranberry

        1984 Lincoln Continental TurboDiesel - rolls coal

        Originally posted by phayzer5
        I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousers

        Comment


          #5
          Jaywish, I did change the tranny oil about less then 10k miles ago (this past February I want to say). I am hoping it is bad gas.

          It is the 97, Thain. The fuel filter was changed I want to say Feb March of this year as well

          What I have noticed now is that the longer and hotter the engine gets, this shaking and jerking (it's not that dramatic, but annoying when you're driving for an hour plus) and it happened under light to light mild throttle. once you romp on it, it doesn't do it.

          What other things should I check???
          "To Find yourself, you must first lose yourself"

          -1973 Volkswagen Bus Westy
          -1986 Honda Magna 700cc
          -1989 Lincoln Town car Signature Series
          -2011 Subaru Outback

          Comment


            #6
            I did use the scanner, no codes!
            "To Find yourself, you must first lose yourself"

            -1973 Volkswagen Bus Westy
            -1986 Honda Magna 700cc
            -1989 Lincoln Town car Signature Series
            -2011 Subaru Outback

            Comment


              #7
              When you are at 60 or whatever and go to give it throttle and it starts to shudder, tap the brake at the same time and see if the shudder goes away. I'm wondering if this is TC shudder.
              These are highly engineered precision vehicles, the first step in diagnosing the problem is to strike the suspected offending part sharply and repeatedly with a blunt object, then re-test.

              Comment


                #8
                When I changed the tranny oil I did put mercon V in there that was about 10K miles ago.

                I wil try the brake test, so basically use two feet to throttle and brake. If it stops when I tap the breaks, what does this mean?
                "To Find yourself, you must first lose yourself"

                -1973 Volkswagen Bus Westy
                -1986 Honda Magna 700cc
                -1989 Lincoln Town car Signature Series
                -2011 Subaru Outback

                Comment


                  #9
                  Applying the brake deactivates the torque converter lockup. If the problem goes away when you do the brake test, this would confirm a TC shudder problem.

                  2000 Grand Marquis LS HPP, a hand-me-down in 2008 with 128,000 km; 175,000 km as of July 2014
                  mods: air filter box 'tuba', headlight relay harness, J-mod (around 186,350 km), 70mm throttle body, KYB Gas-A-Just shocks, aluminum driveshaft, ARA3 PCM

                  Comment


                    #10
                    Ok, I have tried to brake and throttle at the same time, and I would still feel the jerking/shudder. I wil l have to do it on the way home today since that is when it's usually worse
                    "To Find yourself, you must first lose yourself"

                    -1973 Volkswagen Bus Westy
                    -1986 Honda Magna 700cc
                    -1989 Lincoln Town car Signature Series
                    -2011 Subaru Outback

                    Comment


                      #11
                      did 97 still have a mechanical fan? If so, the thermal clutch could be shot and the secondary e-fan not able to keep the engine temps where they should be. It's not enough to overheat, but enough to make it too warm and mat cause some pinging that way too. Pop the hood and watch the fan when you shut off the car. If it's good and warm, it should stop within one second. If it spins for a bit, that's the problem.

                      Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
                      rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)
                      Originally posted by gadget73
                      ... and it should all work like magic and unicorns and stuff.
                      Originally posted by dmccaig
                      Overhead, some poor bastards are flying in airplanes.

                      Comment


                        #12
                        Good advice!! I will look at that, FYI the temp gauge doesn't show it getting HOT, but normal. I will have to find a way to observe it while I shut off the car
                        "To Find yourself, you must first lose yourself"

                        -1973 Volkswagen Bus Westy
                        -1986 Honda Magna 700cc
                        -1989 Lincoln Town car Signature Series
                        -2011 Subaru Outback

                        Comment


                          #13
                          if the gauge isn't doing any creep up... then you're probably fine there.

                          Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
                          rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)
                          Originally posted by gadget73
                          ... and it should all work like magic and unicorns and stuff.
                          Originally posted by dmccaig
                          Overhead, some poor bastards are flying in airplanes.

                          Comment


                            #14
                            Well, i checked the fan, not sure if its thermal or mechanical but when I turned the motor off, it took 2 seconds for the fan to stop

                            the brake TC test, with foot on the gas at the same time, i put my foot on the brake, it was hard to distinguish, but it seems as thought it would go away, but other times, if i keep driving with both feet on the has and brake i would still feel the shaking
                            "To Find yourself, you must first lose yourself"

                            -1973 Volkswagen Bus Westy
                            -1986 Honda Magna 700cc
                            -1989 Lincoln Town car Signature Series
                            -2011 Subaru Outback

                            Comment


                              #15
                              mechanical with a thermal clutch. yeah... the clutch is a little weak, but should be good enough for now.

                              Only two things are infinite, the universe and human stupidity, and I'm not sure about the former. -- Albert Einstein
                              rides: 93 Crown Vic LX (The Red Velvet Cake), 2000 Crown Vic base model (Sandy), 2003 Expedition (the vacation beast)
                              Originally posted by gadget73
                              ... and it should all work like magic and unicorns and stuff.
                              Originally posted by dmccaig
                              Overhead, some poor bastards are flying in airplanes.

                              Comment

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