Engine Knocking
Thread Starter
Racer
Joined: Jul 2004
Posts: 408
Likes: 0
From: Buffalo NY
Engine Knocking
I have a motor that when the engine is under load at a mid to high rpm sounds like it is knocking. Is this most likely detonation? Does it sound like I have my distributor too far advanced?
At this point I am just hoping that it isnt something internal, but since the sound is linked to loading the engine as opposed to just engine speed I wasn't sure.
At this point I am just hoping that it isnt something internal, but since the sound is linked to loading the engine as opposed to just engine speed I wasn't sure.
Burning Brakes
Joined: Feb 1999
Posts: 1,190
Likes: 1
From: SIMI VALLEY CA
Ok throw away the timing light. Unplug your vacuum advance and plug the line. Now with the engine idling turn the distributor slowly towards the front of the car (adavancing), the rpms will increase,keep turning till the motor runs rough. Then turn the distributor towards the rear (retarding) of the car until the motor runs smooth again. It will probably take a few times to get the feel of it. If you check it with a good quality light you’ll be surprised how close (or even right on) you can get.
Thread Starter
Racer
Joined: Jul 2004
Posts: 408
Likes: 0
From: Buffalo NY
Sorry, I guess I should have stated that this wasnt on my Vette. This car doesnt have vacuum advance, just mechanical, and it when I set the timing at idle, it sounded good, idled smoothly, it was just when I loaded the engine at higher rpms that I started to get the noise. I am not entirely sure its pinging, is there something else that could make noise without causing the engine to run terrible.
Team Owner
Joined: Sep 2003
Posts: 88,393
Likes: 2
From: eville in
Originally Posted by JIM
Ok throw away the timing light. Unplug your vacuum advance and plug the line. Now with the engine idling turn the distributor slowly towards the front of the car (adavancing), the rpms will increase,keep turning till the motor runs rough. Then turn the distributor towards the rear (retarding) of the car until the motor runs smooth again. It will probably take a few times to get the feel of it. If you check it with a good quality light you’ll be surprised how close (or even right on) you can get.
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Melting Slicks
Joined: Jul 2004
Posts: 3,304
Likes: 8
From: Avon, Indiana
If it's only under load such as going up a hill, and it sounds like shaking gravel in a tin can, it is probaly too much advance. I had the same problem and someone on the forum gave me the solution.
Start by turning the distributor about two degrees to the right.
Start by turning the distributor about two degrees to the right.