Can a carburetor cause an knock

Engine, ignition, fuel, cooling, exhaust

Moderators: Ranchero50, DuckRyder

Post Reply
JMcTurnan

Can a carburetor cause an knock

Post by JMcTurnan »

So I got this junk yard carburetor, I got it running. And it ran for a bit then the carburetor [censored] up, its a hunk of junk. But anyways since I've had it my engine seems to be knocking, but sometimes when it warms up and the carb seems steady it quits. Can a carb running rough cause a knock? I really violent one? Or am I in the whole with a broken piston rod? I hope not, its a new engine.
User avatar
fireguywtc
100% FORDified!
100% FORDified!
Posts: 3682
Joined: Thu Sep 11, 2008 7:37 pm
Location: North Alabama

Re: Can a carburetor cause an knock

Post by fireguywtc »

I dont think a carb can cause a knock noise itself, theres nothing in there moving like in the engine that would make noise. Even if there were some kind of noise from it, I would think it would be when you move the throttle and it wouldn't be very loud.

You will have to do some more investigating to see were the knock is coming from. Did you clean the carb or go through it before you installed it? You may have sucked something into the engine and cause damage if you didn't. Is the knock a constant noise or intermittent?
Bill
1967 F-250 LWB 2WD 352 V8, 4spd manual, true duals, 122k original miles (currently being restored)
1970 F-250 4x4 highboy ranger 390 V8, 4spd
2012 F-350 PSD FX4 LWB CC lariat, white
http://www.fordification.com/galleries/ ... hp?uid=602
"If you want to judge a person's true character, give them power."
JMcTurnan

Re: Can a carburetor cause an knock

Post by JMcTurnan »

It stops when you push on the throttle, its really hard to tell where its coming from. I did a thorough cleaning, im just hoping it isnt a rod. Im not really sure, I need a new carburetor is what I need. When I get it I will definetly know, but yea it is a possibility, maybe something fell out, God I hope not. Its more of a constant random noise when your off the throttle.
JMcTurnan

Re: Can a carburetor cause an knock

Post by JMcTurnan »

Bump
User avatar
Redcap
Blue Oval Fanatic
Blue Oval Fanatic
Posts: 947
Joined: Mon Dec 20, 2004 10:29 pm
Location: Washington, Centralia
Contact:

Re: Can a carburetor cause an knock

Post by Redcap »

No.
User avatar
papabug71
100% FORDified!
100% FORDified!
Posts: 2002
Joined: Mon Oct 13, 2008 11:31 pm
Location: McAlester, Oklahoma

Re: Can a carburetor cause an knock

Post by papabug71 »

Knock is caused by timing/ignition issues or bad fuel. It almost sounds like its out of time.

Or it could be fixin' to swarm on ya.
Image
Matt
1971 F-100 Sport Custom - My grandpaws truck
Been in the family since 10/3/'71 (Brand spankin' new)
Mine since 5/7/'94
302 / 3 speed / 3:25's
--Currently undergoing full frame off resto/mod--
JMcTurnan

Re: Can a carburetor cause an knock

Post by JMcTurnan »

Well I put it in time and it sounded really nice, and the knock stopped. But than the next time I started it had gotten worse. So I'm not sure, someone told me if the air and fuel ratior and the carburetor isn't spreading right than it causes combustion before it gets to the piston. Does this sound right to any of you? But true, it never started untill I put the new electronic ignition on, also never happened till I put this carburetor on.
User avatar
sideoilerfe
Blue Oval Fanatic
Blue Oval Fanatic
Posts: 804
Joined: Tue Sep 11, 2007 10:04 pm
Location: Oregon, Portland

Re: Can a carburetor cause an knock

Post by sideoilerfe »

JMcTurnan wrote:it never started untill I put the new electronic ignition on, also never happened till I put this carburetor on.
There's your answer. What kind of ignition did you use? Be specific. What kind of carburetor is it? Carburetor's don't knock.
Side oiler FE, see if you can catch me!!!

1970 F250 4x4 390/4spd
1968 F250 4X2 360/C6/No Rust!
JMcTurnan

Re: Can a carburetor cause an knock

Post by JMcTurnan »

Im not sure what type of dizzy, my cousin got it for me for free. The carb is a holly.
User avatar
Redcap
Blue Oval Fanatic
Blue Oval Fanatic
Posts: 947
Joined: Mon Dec 20, 2004 10:29 pm
Location: Washington, Centralia
Contact:

Re: Can a carburetor cause an knock

Post by Redcap »

JMcTurnan wrote:Im not sure what type of dizzy, my cousin got it for me for free. The carb is a holly.
You should probably find out what kind of distributor then.
Post Reply