Author Topic: clanking sound in engine when starting  (Read 11509 times)

Offline 77 cc lb

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clanking sound in engine when starting
« on: April 29, 2010, 02:19:10 pm »
hey everyone! i've got a situation. i went to go  start my 74 292-6 i heard a clanking sound for a couple seconds and then she started. next day go to start clanking louder, little longer and starts. today clanking same, start and then 10 miles down the road starts spitting and sputtering. then i get off highway and dies on me. go to start it about 6 hrs. later try to re-start, clanks and starts, drive about 10 miles to get it home and she dies again. now  it turns over while making clanking sound but won't start. could it be timing chain, crankshaft, distributor? any ideas would be appreciated. thanks
« Last Edit: April 29, 2010, 03:29:42 pm by 77 cc lb »
87 Chevy crewcab shortbed soon to have a 454/400

Offline Blazin

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Re: clanking sound in engine when starting
« Reply #1 on: April 30, 2010, 01:02:46 am »
Because of the stalling part it might not be, but it can't hurt to check the flywheel / flex plate?
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Offline Donut

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Re: clanking sound in engine when starting
« Reply #2 on: April 30, 2010, 04:52:21 am »
Can you pinpoint a little closer on the clanking?  Is it getting fuel?  I personally haven't touched a 6 in years.
I asked about fuel because when I first got my truck I had a noise i couldn't identify, turns out the arm on my mechanical fuel pump was broken and would only work part time.

Is the clanking only when you try to start or when it's running also?
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Offline 77 cc lb

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Re: clanking sound in engine when starting
« Reply #3 on: April 30, 2010, 06:31:34 pm »
i checked the flywheel today and the teeth seemed fine, some had a groove on side of teeth but not all. i thought it was the fuel pump also but i cut it out all together and just running elec. pump, but still having trouble getting fuel. i got it to run again today somehow and drove another 8-10 miles and seemed like it was slipping out of gear. would press on gas and just stop going, let off and fuel would start flowing again.
87 Chevy crewcab shortbed soon to have a 454/400

Offline 77 cc lb

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Re: clanking sound in engine when starting
« Reply #4 on: May 05, 2010, 04:08:17 pm »
hoping to get some more feedback. in reply to donut, it does'nt seem to make the noise while running. i pulled fuel pump, arm is fine, pulled dist. and gears and shaft are'nt mangled. could it be a rod or something internal. i'm going to drain oil and start checking around the bottom end. any ideas greatly appreciated!!
87 Chevy crewcab shortbed soon to have a 454/400

Offline 77 cc lb

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Re: clanking sound in engine when starting
« Reply #5 on: May 13, 2010, 07:19:07 pm »
found out today i have 1 of tha bolts loose on the flywheel. any tricks or short cuts to movin tranny greatly appreciated!!
87 Chevy crewcab shortbed soon to have a 454/400

Offline jaredts

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Re: clanking sound in engine when starting
« Reply #6 on: May 14, 2010, 08:36:48 am »
You can get some long bolts or all thread the same thread as the correct ones (bellhousing to engine).  This will allow you to slide it back and then make it easy to slide back up to the engine without muscling it into place (is muscling a word???).

Offline 77 cc lb

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Re: clanking sound in engine when starting
« Reply #7 on: May 14, 2010, 09:32:02 am »
so i just put longer bolts in and disconnect the driveshaft and then pull back.
87 Chevy crewcab shortbed soon to have a 454/400

Offline jaredts

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Re: clanking sound in engine when starting
« Reply #8 on: May 14, 2010, 11:23:31 am »
so i just put longer bolts in and disconnect the driveshaft and then pull back.
You got it.  Of course you still need to support the weight of the transmission on a jack, but it won't try to slide around on you and makes it a lot easier.

Offline 77 cc lb

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Re: clanking sound in engine when starting
« Reply #9 on: May 14, 2010, 12:02:09 pm »
thanks jaredts,i appreciate that info. is there an easy way to disconnect driveshaft from tranny. sorry, not experienced in engine and trans work. thanks again
87 Chevy crewcab shortbed soon to have a 454/400

Offline ccz145a

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Re: clanking sound in engine when starting
« Reply #10 on: May 14, 2010, 12:40:57 pm »
is there an easy way to disconnect driveshaft from tranny.

Easy or not, there is only one way. Unbolt the saddle straps at the rear end. If its a two-piece shaft, unbolt the support bearing in the middle. Mark orientation of shaft at the rear end yoke and center bearing to ensure the same balance when you put it back together.
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Offline 77 cc lb

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Re: clanking sound in engine when starting
« Reply #11 on: May 14, 2010, 12:49:04 pm »
thanks for the info. i'm going to try and work this out.
87 Chevy crewcab shortbed soon to have a 454/400

Offline 77 cc lb

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Re: clanking sound in engine when starting
« Reply #12 on: May 14, 2010, 07:04:54 pm »
will i have to pull the tranny all the way out and down to put on a new flywheel or can i just move it back a few inches?
87 Chevy crewcab shortbed soon to have a 454/400

Offline Irish_Alley

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Re: clanking sound in engine when starting
« Reply #13 on: May 15, 2010, 12:40:52 am »
i haven't had to do it that way but the bolt ideal seams to make sense and if you pick up 4" bolts i would think that would be plenty to get a ratchet in there or at least a wrench
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Offline Senior1978

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Re: clanking sound in engine when starting
« Reply #14 on: June 01, 2010, 09:00:01 pm »
Hey....back in the day that is how we did it. put in long bolts to support. have a jackstand for added backup. use a flat combo wrench. Kinda like a "old style 7/16 tappet wrench." It is thinner, I personally would replace all the bolts. Use loctite red for added security. Put it all back together. go for a drive
Good Luck
Mark
78 Chev. C20HD...9600GVWR, GMCrate 350/290HP, THM400, Dana60-4.10. Daily driver/work in process. Originally a "pipeline special" Custom Deluxe, 1 Ton springs/Brakes/Axles.