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Strange noise coming under the hood at the back of the motor

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    Strange noise coming under the hood at the back of the motor

    Hello Again and A Great Friday to all.
    This just started a couple of days ago. At low rpm while driving or just starting off idle I hear a sound that seems to be coming from the engine compartment possibly near the engine and transmission intersection. It sounds like the sound when we used to put a playing card on the bicycle spokes when we were little. It goes away as soon as the RPMS are a little higher.

    Can this be torque converter or flywheel related? I have only noticed when in first gear. It may happen in the other gears I just have not noticed. The motor is a 1989 Mark 7 HO and the transmission is a 1991 GM AOD transmission that I hope to rebuild soon using the Wide Ratio gear set and a 2400 rpm or so torque converter.
    I should have the 3.55L in before the rebuild. I hope.
    Thank you again,
    Mike
    90 Colony Park LS with GT 40 heads and intake. HO cam, 65 MM TB, 67 MM EGR spacer. Has a 75 MM Pro Flow mass air sensor. Borla XS mufflers. 3L55. Shift kit, 2000 stall Tq convertor...Bilstein shocks, front and rear sway bars.
    90 Colony Park LS 64,000 miles all original. 3L55 tow package....front and rear sway bars.
    91 Grand Marquis GS....HO motor..Bilstein shocks poly bushings and police swaybars. This one handles the best.
    70 Torino Squire with M code 351 Cleveland 3.00 has Magnaflow mufflers. Hidden headlights and power windows. All original

    #2
    does it sound similar to a power steering pump that is low on fluid? If so, its a check ball in the transmission buzzing. They do that at slightly high TV pressure and with some wear in the check ball bore. Its nothing to worry about.
    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


      #3
      It actually sounds like the fan is hitting the fan shroud, not as loud though.

      I do have bad motor mounts but this sounds like it is at the back of the motor.

      What do bad main bearings sound like? It seems like a little vibration too. Very little.


      I do thank you Gadget.



      Originally posted by gadget73 View Post
      does it sound similar to a power steering pump that is low on fluid? If so, its a check ball in the transmission buzzing. They do that at slightly high TV pressure and with some wear in the check ball bore. Its nothing to worry about.
      90 Colony Park LS with GT 40 heads and intake. HO cam, 65 MM TB, 67 MM EGR spacer. Has a 75 MM Pro Flow mass air sensor. Borla XS mufflers. 3L55. Shift kit, 2000 stall Tq convertor...Bilstein shocks, front and rear sway bars.
      90 Colony Park LS 64,000 miles all original. 3L55 tow package....front and rear sway bars.
      91 Grand Marquis GS....HO motor..Bilstein shocks poly bushings and police swaybars. This one handles the best.
      70 Torino Squire with M code 351 Cleveland 3.00 has Magnaflow mufflers. Hidden headlights and power windows. All original

      Comment


        #4
        Air Tubes for the cats? Maybe


        Sent from my iPhone using Tapatalk

        Comment


          #5
          Almost sound like its smog/air pump related. Is all the related plumbing in tact? The thermactor valves like to fall apart.

          1981 Mercury Marquis Brougham 2-Door 302/ 5-speed -special blend (GMGT)
          1987 Lincoln Mark VII 5-speed (Errand runner)
          1989 Mercury Grand Marquis (Base Runner)
          2007 Lincoln Town Car Signature Limited (Hustlyn)
          2011 Ford Crown Victoria Police Interceptor (Down with O.P.P)

          Comment


            #6
            That's what I was getting at lol


            Sent from my iPhone using Tapatalk

            Comment


              #7
              Thank you all again,
              I will be checking and digging into it when it quits raining.


              Thanks
              90 Colony Park LS with GT 40 heads and intake. HO cam, 65 MM TB, 67 MM EGR spacer. Has a 75 MM Pro Flow mass air sensor. Borla XS mufflers. 3L55. Shift kit, 2000 stall Tq convertor...Bilstein shocks, front and rear sway bars.
              90 Colony Park LS 64,000 miles all original. 3L55 tow package....front and rear sway bars.
              91 Grand Marquis GS....HO motor..Bilstein shocks poly bushings and police swaybars. This one handles the best.
              70 Torino Squire with M code 351 Cleveland 3.00 has Magnaflow mufflers. Hidden headlights and power windows. All original

              Comment


                #8
                Gadget, is there an easy fox for this? It's driving me nuts. In 'D' with my foot on the brake it sounds like I have a gear drive instead of a timing chain...or a dry power steering pump - in 'P' it goes away. It gradually goes away as you accelerate. It's gotten louder over the past 2 years to the point where it sounds like somehting is really wrong...would another valve body be in order?
                sigpic
                1988 Grand Marquis LS (White Lightning), 2003 Mercury Marauder (SOLD),1979 Mercury Cougar XR-7
                http://landyachts.homestead.com/page5.html,1951 Merc on a '88 Lincoln Town Car Chassis:http://landyachts.homestead.com/index.html

                Comment


                  #9
                  Kind of a whirring sound? My 90 has done that ever since the trans rebuild 7 years ago.
                  1990 MGM: $50 E7 heads, HO cam, Holley SysteMAX lower intake, HO upper intake with an Explorer TB. LSC ECM. Lincoln logs into stock dual exhaust. K&N drop in air filter. Wide ratio AOD, 2400 converter with a 3.08 one tire fire out back. Car is less slow now. Then there's the '92 Beater. Dual 2.25" exhaust with shiny tips. Rumbles nice. Super slow. Burns oil too.

                  Comment


                    #10
                    That sounds like the AOD buzz. It is quite common and natural. But, make sure the fluid level is where it should be.

                    1981 Mercury Marquis Brougham 2-Door 302/ 5-speed -special blend (GMGT)
                    1987 Lincoln Mark VII 5-speed (Errand runner)
                    1989 Mercury Grand Marquis (Base Runner)
                    2007 Lincoln Town Car Signature Limited (Hustlyn)
                    2011 Ford Crown Victoria Police Interceptor (Down with O.P.P)

                    Comment


                      #11
                      Originally posted by HiFiMerc View Post
                      Kind of a whirring sound? My 90 has done that ever since the trans rebuild 7 years ago.
                      I know the buzzing sound everyone is talking about. When new these cars did it. I recall it in 1985... But this is a very loud hydraulic whine, very similar to a dry power steering pump. It increases with RPM if you ease your foot on the gas and hold the brake. The car didn't do it when I bought it in '09 and about 10,000 miles ago. If anything, it's becoming louder.

                      I know it's "normal", and "ok" and "not to worry about it"...but should I finally decide to sell this car in the very near future, I don't want to have to try explain to someone that is not familiar with them that this annoying sound you hear is... "normal...don't worry about it."

                      It's not normal. They didn't sound like this from the factory. Basically, I want to correct it if it's not too involved so as to not scare off potential buyers.

                      113,000 miles. Fluid looks good and is where it should be. TV cable bushing is there (I replaced the original before it needed replacement just in case.) It's not the power steering fluid being low. It's not emissions related. It's coming from underneath the car, about at the driver's door. It makes no difference if it's cold or fully warmed up.

                      I suspect it's the fluid pump whining in the trans.
                      Last edited by mercman1951; 04-07-2014, 08:48 PM.
                      sigpic
                      1988 Grand Marquis LS (White Lightning), 2003 Mercury Marauder (SOLD),1979 Mercury Cougar XR-7
                      http://landyachts.homestead.com/page5.html,1951 Merc on a '88 Lincoln Town Car Chassis:http://landyachts.homestead.com/index.html

                      Comment


                        #12
                        it's either that or the check balls in the valve body.

                        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.

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