Alright guys, maybe you can lend a hand. Two problems here, and they're on my daily driver and much beloved car. First off, it's a '90 Grand Marquis with about 100,000 miles.Car ran flawlessly when i got it about 4-5 months ago with about 85,000 on it. About a month ago, I removed the smog pump/thermactor and got rid of the attached vacuum line, capping off both smog control solenoids. At the same time I also replaced the stock plenum with the HO (I have yet to bore out the egr and replace the throttle body.) All the vacuum lines are attached with no leaks (though the line leading to the map sensor is a little dry rotted, but isnt leaking). After the smog removal and intake swap, car ran just as perfect as it had, no difference was noticeable. I did not but a belt back on the left side, as the 56" i bought was too short any way you looked at it, and the ac didnt work anyway. Now, upon starting the car it doesnt idle as strong as it used to, seems to shake more, and is louder. After being run, she idles strong, but is still a little loud. I'm not concerned about the volume so much as the mild knock noise that is persistent at idle. In addition, after the initial start, when you shift into reverse, or any drive gear, there is a dull almost scraping noise when idling in any gear. The noise is only present in reverse, first, and second gear. After running a few miles, the noise dissapears completely and stays away until you turn the car off, let it cool completely and start it back up. Both oil levels are good and the oils in good shape. I really need my transportation, and would hate to get rid of my car, as i'm very attached to it. Any help?
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The knocking could be a bearing getting tired in the bottom end. Its not uncommon. An oil pressure check would probably tell you for sure. If thats what it is, there really isn't anything to be done for it, and frankly I wouldn't even worry about it as long as you've got some oil pressure.
The scraping noise I'd actually suspect is an alternator bearing, or possibly the fan hitting the shroud. Dead motor mounts will let the motor sit down further than it should, and the fan will tick off the plastic. Look in there with the motor not running and see if the bottom edge of the shroud looks worn down.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 -
Okay, bearing sounds logical, and not intensely worrying. New info: the fan shroud was knocked out of place about a week and a half ago after i got into an 8 mph rear end collision with a damn mercury sable and made a horrendous clacking scraping noise, but i fixed it the next day. Next, the alternator is less than 2 months old and shouldnt be scraping, plus the scraping noise is only heard when the transmission is engaged, so still a little worried. Trans fluid is a pleasant red, no burning smell or discoloration, slightly overfilled. dont want to pay 1200 for new aod install. (I' do it myself, but i have neither the tools nor manpower.) Thank you much for your input thus far, though.Comment
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I'd still not completely rule out a motor mount issue. If they're soggy, the motor will move around a lot. On cars that have had oil leakage issues, those motor mounts have all the structural integrity of a bowl of jello. If you're so inclined, pull the fan shroud totally and see if anything changes.
Other random thought, have you ever checked to see if the starter bolts are tight? Wouldn't be the first time I've heard of one coming loose. I'm wondering if maybe its not so firmly attached, and putting the trans in gear isn't causing things to shift around just enough to rub on the starter. This could also account for the knocking sound.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 rousersComment
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On the wagon with the newer motor I always had a metallic scraping/knocking sound whenever I'd be idling in gear. I attributed it to a slightly bent flexplate or maybe the balance weight being too high, and I tried to allow some extra clearance when I installed the same engine in the Vic.2012 Mazda5 Touring | Finally working on the LTD again!
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