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Topic: Re: Engine rattle above 2000 rpm

in Forum: C3 Engines


Re: Engine rattle above 2000 rpm

Posted: 8/11/13 8:58pm Message 21 of 38
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Vancouver, WA - USA
Joined: 8/25/2005
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Vette(s): 1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
Man, sorry to hear that, Greg!  Bummer!  Timing chain, maybe???



 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
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Re: Engine rattle above 2000 rpm

Posted: 8/12/13 6:27am Message 22 of 38
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Canada
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Posts: 230
Vette(s): 1975 Corvette 383 stroker w/Patriot 190 heads, Eagle stroker kit, Comp 279TH7 cam, DUI distributor, Edelbrock 7116 intake, Edelbrock 1806 carb, Hedman Hedders, TH400 w/TCI Breakaway 2400 stall, Transgo 1-2 shift kit.
daveo76 said: Man, sorry to hear that, Greg!  Bummer!  Timing chain, maybe???

Thanks Dave. I haven't had a chance to start the post-mortem yet but timing chain did cross my mind. So did spun crank bearing and a bunch of other possibilities.




Build Date: May 7, 1975. 383 w/267 RWHP/310 RWTQ

Re: Engine rattle above 2000 rpm

Posted: 8/12/13 10:35am Message 23 of 38
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Duncanville, TX - USA
Joined: 11/8/2003
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Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
Case75 said:...the engine made a quite a death rattle and a squeal and quit before I could reach the key. Unhappy


Ruh Roh....sounds like bad news to me....will the engine still crank over, or is it seized up? The description sure sounds like it seized up on ya....Cry

What does the oil smell like on the dipping stick?

Couple more kweschuns...
Did the engine shut off, or did the car just quit moving?
Will it start back up now?
A broken flywheel can make the same noises....and sometimes it might even still start the car.


|UPDATED|8/12/2013 10:35:04 AM (AZT)|/UPDATED|



Joel Adams
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Re: Engine rattle above 2000 rpm

Posted: 8/12/13 12:25pm Message 24 of 38
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Canada
Joined: 6/19/2012
Posts: 230
Vette(s): 1975 Corvette 383 stroker w/Patriot 190 heads, Eagle stroker kit, Comp 279TH7 cam, DUI distributor, Edelbrock 7116 intake, Edelbrock 1806 carb, Hedman Hedders, TH400 w/TCI Breakaway 2400 stall, Transgo 1-2 shift kit.
Adams' Apple said:
Case75 said:...the engine made a quite a death rattle and a squeal and quit before I could reach the key. Unhappy


Ruh Roh....sounds like bad news to me....will the engine still crank over, or is it seized up? The description sure sounds like it seized up on ya....Cry

What does the oil smell like on the dipping stick?

Couple more kweschuns...
Did the engine shut off, or did the car just quit moving?
Will it start back up now?
A broken flywheel can make the same noises....and sometimes it might even still start the car.




Well Joel, I haven't attempted to crank the engine. It quit on it's own while under power at about 40 mph with a knock and a squeal. Haven't pulled the dipstick either. Won't I hurt the starter motor if it is seized; I guess not if I just try it quick. New distributor arrived today from DUI and it's a beauty. At least I'll have it for the rebuild or replacement.




Build Date: May 7, 1975. 383 w/267 RWHP/310 RWTQ

Re: Engine rattle above 2000 rpm

Posted: 8/12/13 2:08pm Message 25 of 38
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Canada
Joined: 6/19/2012
Posts: 230
Vette(s): 1975 Corvette 383 stroker w/Patriot 190 heads, Eagle stroker kit, Comp 279TH7 cam, DUI distributor, Edelbrock 7116 intake, Edelbrock 1806 carb, Hedman Hedders, TH400 w/TCI Breakaway 2400 stall, Transgo 1-2 shift kit.
Some good news. Just tried and the engine will turn over so it's not seized. It won't start though.


Build Date: May 7, 1975. 383 w/267 RWHP/310 RWTQ

Re: Engine rattle above 2000 rpm

Posted: 8/12/13 2:28pm Message 26 of 38
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Germansville, PA - USA
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Vette(s): 1974 Coupe 358ci 4 speed Black w/Medium Saddle interior w/79 custom leather seats. . 1999 C5 Convertible, 6 speed, Atomic orange, Oak interior.
Well if is the timing chain/gear that went  you've just bent pushrods and maybe some valves stems. Happened to me. Same thing, just shut down while driving and wouldn't start. If you still have the stock plastic cam gear that isd what usually breaks. Cry


   

DanT

Re: Engine rattle above 2000 rpm

Posted: 8/25/13 7:18pm Message 27 of 38
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Joined: 6/19/2012
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Vette(s): 1975 Corvette 383 stroker w/Patriot 190 heads, Eagle stroker kit, Comp 279TH7 cam, DUI distributor, Edelbrock 7116 intake, Edelbrock 1806 carb, Hedman Hedders, TH400 w/TCI Breakaway 2400 stall, Transgo 1-2 shift kit.
danascar said: Well if is the timing chain/gear that went  you've just bent pushrods and maybe some valves stems. Happened to me. Same thing, just shut down while driving and wouldn't start. If you still have the stock plastic cam gear that isd what usually breaks. Cry

Well, I finally got around to pulling the valve covers and spark plugs. No top end damage that I can see and all 8 plugs look good; some carbon build up in cylinders 1 and 2 but no signs of detonation damage in the plugs, no oil fouling on them either. That's all the time I've had to look at things though.




Build Date: May 7, 1975. 383 w/267 RWHP/310 RWTQ

Re: Engine rattle above 2000 rpm

Posted: 8/26/13 11:12am Message 28 of 38
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Grapevine, TX - USA
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Vette(s): 1972 LT-1 convertible with factory air. 2017 Black Rose Grand Sport convertible.
Not too sound too dumb, but does it have enough oil in it?


   

Re: Engine rattle above 2000 rpm

Posted: 8/26/13 5:23pm Message 29 of 38
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Canada
Joined: 6/19/2012
Posts: 230
Vette(s): 1975 Corvette 383 stroker w/Patriot 190 heads, Eagle stroker kit, Comp 279TH7 cam, DUI distributor, Edelbrock 7116 intake, Edelbrock 1806 carb, Hedman Hedders, TH400 w/TCI Breakaway 2400 stall, Transgo 1-2 shift kit.
F4Gary said: Not too sound too dumb, but does it have enough oil in it?


Right to the top of the mark on the dipstick.



Build Date: May 7, 1975. 383 w/267 RWHP/310 RWTQ

Re: Engine rattle above 2000 rpm

Posted: 8/26/13 8:06pm Message 30 of 38
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Duncanville, TX - USA
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Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
Greg, have you tried cranking it with the plugs out?
Does the distributor rotor turn when you crank it over?
Does the engine oil smell "funky", or like it is burnt?
Do you have access to a bore scope?
It's possible that one(or more) of the wrist pins has worked loose from a rod, and is scraping on a cylinder wall. Not a good thing, for sure.

I'm thinking hard about what you said about the distributor moving, even tho it is tightened down as tight as the clamp will go. Imma wondering if the dadgum distributor itself hasn't taken a dump. Not the electrical part, but an actual mechanical failure...like the gear melting, or the pin on the gear shearing off...or the teeth themselves wearing off.
IF the dist. shaft itself was really tight down in the hole, it could mash the gear up against the oil pump too tight, and also against the boss in the block.

I'm REALLY hoping this isn't a major engine failure. Normally, if a rod, or crank bearing has taken a doo-doo(hi-teck terminology), the oil will smell bad. It also usually will cause the engine coolant temp to go high.
A rod pin coming out will scrape against the cylinder wall, also normally causing a higher than normal coolant temp, and lottsa metal in the oil.

A jumped timing chain will not normally damage any of the valve train parts, unless you have domed pistons, or a really high-lift cam...or rockers that are adjusted way too tight.

I'd really start checking the distributor....see if the rotor will turn with the engine, and that you cannot turn it(the rotor) by hand....

Fingers crossed....



Joel Adams
C3VR Lifetime Member #56    

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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

in Forum: C3 Engines


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