After my engine warms up and upon putting a load on the engine, as in shifting to high, or going up a slight grade, I am hearing a very loud audible metallic sound coming from (one) or more of my coils. Has anyone had this happen before? It runs very well until it warms up and does this. It does not seem to alter the performance of the motor, just really irritatingly loud.
Does it change with the position of the spark lever? Usually the coils make the same noise at all times when the engine is running, but Loose main bearings, or loose pistons will make more noise under power. In that case retarding the spark will make the spark come earlier and usually make the noise less or stop entirely. If it stops when you retard a little, it might just be what is called "spark knock".
Norman, It is definitely coming from the coil box and is the same with or without the cover on it. Audibly a loud metallic or high pitch sound much louder than the normal click of the coils. It does not change much in the tone of sound when changing the spark lever either way. It only stops when the engine load is taken off. I have been driving T s for over 30 years and have never had this happen before.
Sounda like an exhaust leak. The packing nut is right under the top floorboard, and can sound like it's coming from the coil box.
Opening up the throttle means more exhaust is produced, making the clicking louder.
Swap them out, one by one with a good known coil.
Check for carbon tracks on the coil box wood, both on the individual coil and box
I have seen a similar situation with coil loud clicking sounds when coil point bridges or vibrator point contacts become loose or detached. This usually causes the engine to miss.
Take a close look at all the coil points and see if they are intact.
Since the sound is load dependent I'm really believing it's not a coil, but maybe a rattle coming from the box itself. Look for anything loose that may cause it when the car shakes harder while under load.
Daniel, use a stethoscope, long screwdriver held to your ear or the like to locate the noise. You'll be amazed at the clicks you will pick up and where is their origin.
Ron, what you suggest sounds feasible, as the sound is definitely coming from the coil box area, only, I do not notice any significant engine miss fire. Will take a closer look at the coils, and perhaps replace them one at a time.
I pulled out the four coils and inspected them. They only have a few miles on them since rebuilt. The gap is correct and there is no evidence of arcing anywhere, nor inside the coil box. All wires are good and tight nothing appears to be wrong, yet still a loud clicking on load and after warm up.
Dennis.... now borrow a known good set of coils...
Any thoughts on my suggestion above?
Also, is the click regular in its beat, as if perfectly "in line" with the timing and frequency of a coil buzz?
If it's more random in its occurrence than I doubt it's actually a coil.
Yes, the clicking is consistent with the coils and in line with the normal timing of the spark. It seems as though it is coming from one of the coils, so I will change them out and test drive it again this evening. I have never had a coil act this way before with no outward indication of a fault. Thanks for chiming in here and offering your assistance.
Well today, I changed out the coils with a set of recently rebuilt ones from my other car and the same thing occurred. I am now wondering of it could be the timer, any thoughts on this?
Rebuild the coil box with the kit offered by Fun Projects.
Bob, The coil box is newly restored with 300 miles on it. One thing I did notice was that when I advanced the spark lever the sound got louder, so could it have something to do with the timer. It also does not matter if it is on magneto or battery, the sound still persists.
You can 'stop' each coil in turn by pressing on the moving point.
If the click is associated with one particular coil, then swap them around.
Repeat the 'stop' check. If the click has moved, it's a coil issue (not necessarily a problem). If it stays in the same box position, it's the box, probably an HT 'leak' tracking to ground.
You might have an idea there re the timer. Open it up and look inside if you haven't already. It probly needs to be cleaned anyway. Other than that, I had a "clicking" noise (two cars, in the same year) that could've been misconstrued as in the timer and turned out to be a loose crank pulley. Put on an adjustable style and end of noise! Yank your belt off and reach down and see if it's loose, but you'll be better off to pull the radiator so you can really get at it. My second loose pulley came off in my hand!