loud knock on start-up help please !
Thread Starter
Cruising
Joined: Dec 2009
Posts: 13
Likes: 0
loud knock on start-up help please !
okay so Ive had my 79 in the shop for a few weeks re-doing the interior, HID's, audio etc. I started it about a week ago and it ran fine. I went to start it today to let the lights down and it was slow to turn over (could be from working with amps/stereo) but then I heard this loud bang/pop. To say the least it scared the sh** out of me. I popped the hood to make sure nothing had fallen in. When I tried starting it again it banged again. Im not sure where its coming from but its not happy... Its no backfire pop but a bang...a hard one.
The car does leak a little oil/tranny fluid but when I checked it had enough in it. idk what it is... Its freezing down here in georgia . Also a few months ago the car felt sluggish while in reverse.
I had planned on getting all the seals replaced and the tranny rebuilt this weekend.
Does anyone have any clue what this bang could be ? Im scared to try to start it again, I tried about 3-4 times. When I try to start the car itl slowly try and turn over and then BANG
The car does leak a little oil/tranny fluid but when I checked it had enough in it. idk what it is... Its freezing down here in georgia . Also a few months ago the car felt sluggish while in reverse.
I had planned on getting all the seals replaced and the tranny rebuilt this weekend.
Does anyone have any clue what this bang could be ? Im scared to try to start it again, I tried about 3-4 times. When I try to start the car itl slowly try and turn over and then BANG
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
I would check all the belts and pulleys, see if something is loose and banging around. Stick your head in there and have someone hit the key, see whats going on and where the noise is coming from. It might be a froze cat in the fan.
Then it could get interesting, might have to pull valve covers and start looking for bent pushrods and the like. If there is nothing obvious in the belt, fans I would pull a valve cover before turning it over even.
Then it could get interesting, might have to pull valve covers and start looking for bent pushrods and the like. If there is nothing obvious in the belt, fans I would pull a valve cover before turning it over even.
Thread Starter
Cruising
Joined: Dec 2009
Posts: 13
Likes: 0
true... ^ ughh... It was fine a week or so ago thats what Im not getting . The car literally sat. Where would I have had to drop a tool for this to be happening ? ... I know thats a sad stupid mistake but its definatelly possible knowing me...
The only time I was under/near the engine would be removing the headlight housings and changing side marker bulbs.
The only time I was under/near the engine would be removing the headlight housings and changing side marker bulbs.
Drifting
Joined: Sep 2010
Posts: 1,581
Likes: 50
From: Prosper TX
If you don't want to remove the valve covers for a quick inspection, the above post about having a helper bump the engine while you visually inspect might be your only option. At least you'll have an idea for the vicinity of the culprit.
Good luck and please post back once you find out what it was!
Intermediate
Joined: Nov 2010
Posts: 28
Likes: 0
If your experience as a mechanic is limited, may I suggest it is time to consult one. Continuing to turn the engine could result in more damage. For example, if a valve spring has broken, it could drop a valve down into the cylinder. This could get impacted by the piston and get pounded into it until the motor is heavely damaged. Better to find someone who can tell you what the noise is, before it gets even more expensive.
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Melting Slicks
Joined: Jul 2005
Posts: 2,740
Likes: 3
From: Aurora Ontario
okay so Ive had my 79 in the shop for a few weeks re-doing the interior, HID's, audio etc. I started it about a week ago and it ran fine. I went to start it today to let the lights down and it was slow to turn over (could be from working with amps/stereo) but then I heard this loud bang/pop. To say the least it scared the sh** out of me. I popped the hood to make sure nothing had fallen in. When I tried starting it again it banged again. Im not sure where its coming from but its not happy... Its no backfire pop but a bang...a hard one.
The car does leak a little oil/tranny fluid but when I checked it had enough in it. idk what it is... Its freezing down here in georgia . Also a few months ago the car felt sluggish while in reverse.
I had planned on getting all the seals replaced and the tranny rebuilt this weekend.
Does anyone have any clue what this bang could be ? Im scared to try to start it again, I tried about 3-4 times. When I try to start the car itl slowly try and turn over and then BANG
The car does leak a little oil/tranny fluid but when I checked it had enough in it. idk what it is... Its freezing down here in georgia . Also a few months ago the car felt sluggish while in reverse.
I had planned on getting all the seals replaced and the tranny rebuilt this weekend.
Does anyone have any clue what this bang could be ? Im scared to try to start it again, I tried about 3-4 times. When I try to start the car itl slowly try and turn over and then BANG
Charge the battery. Get someone to kick it over. Open the hood. Stand on the passengerside. Look down at the starter and see if the noise is coming from that area. If it does, check to see if the three bolts that hold the starter to the engine are tight. If they are tight change the starter.
If it bangs after it starts that could be a different problem. All kinds of things come to mind from minor to serious. I doubt it serious if it ran fine a week ago then suddenly started to do it.
Based on what you were working on I doubt you could have dropped anything anywhere that would cause that noise.
Jim
