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#1
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440 with grinding noise at idle in P
I have a 1967 +.030" 440 engine with an oscillating grinding noise at idle. It seems to be coming from the front crank area. Engine has roughly 80k miles on it, nearly full of oil with good pressure. Steel crank, balanced, forged pistons, pulley with 4 belts on it. Pulley is tight. Motor just started this noise last week. When tranny is dropped in D, noise stops. I got under the truck looking for rubbing of the pulley on the lowest water pump housing bolt, all looks OK. Checked the power steering and alternator to verify that the sound is not coming from them. Engine has a Hughes HE1423 cam, double roller chain. Oil is clean and engine runs fine, no missing or lacking of power. The sound is a metalic ccrrrr, ccrrrr type of sound as it runs, and it varies with the RPM. There is no oil leaking anywhere. Hope I did not snap another crank behind the first counter weight................. I guess the next move is to loosen the belts and check for crank end play. Could it be the oil slinger on the nose of the crank?
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#2
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The fact that the noise stops when the trans is placed in gear could be a sign of excessive end play in the crank (worn thrust main) that could be sending the oil slinger or harmonic balancer against the front cover.
Have you checked the clearance between the harmonic balancer outer ring and the front cover; they're known to come loose? |
#3
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I agree with John--it's probably and sadly enough the thrust bearing. I hope you had your crank nitirided-The 451 I saw this happen in had a nitrided crank and the crank was unmarked-the bearing-destroyed!
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#4
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you haven't mentioned if you have looked at this, but i have seen auto trans cooler lines that rub on the balancer or pulley. it sounds bloody terrible, i would hope for your sake it could be something simple like that? maybe it touches just enough when engine is "relaxed" in neutral or park, then with a bit of load the mounts may give just enough to let the lines come off the pulley? im guessing though that you would have seen anything like that. good luck, and let us know what you find. ben simpson
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#5
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Loose flexplate bolts, maybe.
torch |
#6
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good suggestion cutting torch, but in my experience that type of problem (loose or cracked flexplate) normally is worse in drive, at idle, and will get better to listen to as the revs come up and the torque converter doesnt have to impart as much load into the plate. it will often disappear in neutral and with 1500 rpm or so.
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#7
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Quote:
torch |
#8
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yeah, i guess many people have been caught many times with problems like you have just described. an uncle of mine who owned a workshop has been sold a few cars with bad noises for next to nothing, only to put them on the hoist and tighten loose bolts! the owners (ex owners) of these vehicles were given quotes by other workshops for major engine rebuilds etc etc. so they get scared, buy another car then offload the noisy one. often its the mechanics trying to score big work but also its hard to believe but true some mechanics are just plain hopeless and wouldnt know otherwise! in my job i see the situation a bit, i am a qualified mechanic, but my paying job is a breakdown mechanic. (roadside assistance-jump starts, keys locked in etc) we often get called to stuff like "i just had this car serviced, mechanic said it needs this and that and blah blah he quoted me $2500", and sometimes it is something as simple as loose converter bolts!
torch, in response to your posting - yes youre dead right, it certainly is worth checking, and in this game, im sure you are aware as well as i am, things dont always follow set rules, do they!! |
#9
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No, they don't. Gotta try to prevent those teethmarks!
torch |
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