Old Cars Rattle
I've been posting a few questions on TheSamba forums lately as I've been narrowing down issues with my Ghia. But, I didn't want the blog to go ignored, so I'll post a summary here for posterity.
The Interesting Case of the Continually Calibrated Carburetor
After finally getting my BTDC and ATDC straight and knowing for sure that I was setting my timing exactly right I was able to get the motor running about as well as can be expected in winter. Once it's fully warmed-up it will idle solidly enough at 850 RPMs, has good throttle response, low-end power and on-par fuel economy (23 in-town, 30 or better highway).
I have to accept the carburetor is 34 years old, though, and probably will never run 100% properly ever again. But, it's pretty good. The only issue seems to be the volume control screw needs to be 8-9 full turns out to keep the engine from stalling when I come to a stop. Standard for a brand new 34 PICT-3 carburetor is 2 1/2 to 3 turns out for the volume screw. My setting sounds common, though, compared to others with carburetors just as old.
It does stall at idle, however, when the engine isn't quite fully warmed-up. That seems not much different from my '72 Super Beetle from 15 years ago, though. Cold weather and center-mounted carburetors don't mix. You need to allow 10 to 15 minutes of warm-up before the engine will operate properly in winter. What happens until such time is the intake manifold is simply too cold and fuel actually condenses on the walls rather than getting to the pistons.
Worrisome Rattle Fixed with Brute Strength
I'd been hearing a disturbing "tock tock tock" sound coming from the front end sometimes when I was turning right and accelerating. It seemed to correspond directly with wheel rotation, so I'd stress out every time I heard it. At first I thought it was a rattling bumper as the right side of the front bumper seemed a bit looser. I tightened that down but the rattle persisted.
My theory of the sound being the bumper even though it corresponded with wheel rotation was because I'd heard that sound before and it was the metal end of a strap on my bike messenger bag in the trunk. It was hitting the top of the gas tank (I don't have a trunk liner like Dad) and the road vibration must have made it tap in-time with the wheels. Because of that I was convinced it was something equally minor just making a racket and not something serious waiting to turn one of the front wheels 90 degrees and kill me dead.
One guy on TheSamba thought it could very well be a loose tie rod ready to come off, turn one of my front wheels 90 degrees and kill me dead. If not that, it was perhaps bad bearings, bad CV joints or lose brake shoe. Other motor-inclined friends of mine thought it sounded like bad bearings, too. There were no other signs pointing toward a loose tie-rod ready to turn a front wheel 90 degrees and kill me dead. But, a bad bearing could seize up a tire and that's not good either.
I read up in the Muir book and the Bentley manual about how to check bearings and CV joints and then spent 1/2 an hour yesterday jacking up each wheel, removing it and checking for just those things. From what I could tell, and someone with more experience might give me a better 2nd opinion, all bearings and CV joints seemed just fine. The tie rods were also nice and tight. No play of any sort in any of those systems.
I did find the source of the noise, though, with about 94.32% certainty. On the left-front disc brake the splash guard was a bit bent at the bottom right by the brake caliper. The splash guard is just a flimsy piece of metal on the inside of the disc that keeps water and dirt from getting on it. The dent in it was close enough to the disc that it looked to be touching at first glance. I imagine that while turning right the wheel gets torqued enough to bend the disc into the splash guard that extra couple millimeters to make a "tock tock tock" sound that corresponds with wheel rotation.
After bending the splash guard back away from the disc easily by hand and replacing the wheel I took the car for a 1/2 hour test drive and never heard the noise again! May all your worrisome car noises turn out as innocuous.
The Interesting Case of the Continually Calibrated Carburetor
After finally getting my BTDC and ATDC straight and knowing for sure that I was setting my timing exactly right I was able to get the motor running about as well as can be expected in winter. Once it's fully warmed-up it will idle solidly enough at 850 RPMs, has good throttle response, low-end power and on-par fuel economy (23 in-town, 30 or better highway).
I have to accept the carburetor is 34 years old, though, and probably will never run 100% properly ever again. But, it's pretty good. The only issue seems to be the volume control screw needs to be 8-9 full turns out to keep the engine from stalling when I come to a stop. Standard for a brand new 34 PICT-3 carburetor is 2 1/2 to 3 turns out for the volume screw. My setting sounds common, though, compared to others with carburetors just as old.
It does stall at idle, however, when the engine isn't quite fully warmed-up. That seems not much different from my '72 Super Beetle from 15 years ago, though. Cold weather and center-mounted carburetors don't mix. You need to allow 10 to 15 minutes of warm-up before the engine will operate properly in winter. What happens until such time is the intake manifold is simply too cold and fuel actually condenses on the walls rather than getting to the pistons.
Worrisome Rattle Fixed with Brute Strength
I'd been hearing a disturbing "tock tock tock" sound coming from the front end sometimes when I was turning right and accelerating. It seemed to correspond directly with wheel rotation, so I'd stress out every time I heard it. At first I thought it was a rattling bumper as the right side of the front bumper seemed a bit looser. I tightened that down but the rattle persisted.
My theory of the sound being the bumper even though it corresponded with wheel rotation was because I'd heard that sound before and it was the metal end of a strap on my bike messenger bag in the trunk. It was hitting the top of the gas tank (I don't have a trunk liner like Dad) and the road vibration must have made it tap in-time with the wheels. Because of that I was convinced it was something equally minor just making a racket and not something serious waiting to turn one of the front wheels 90 degrees and kill me dead.
One guy on TheSamba thought it could very well be a loose tie rod ready to come off, turn one of my front wheels 90 degrees and kill me dead. If not that, it was perhaps bad bearings, bad CV joints or lose brake shoe. Other motor-inclined friends of mine thought it sounded like bad bearings, too. There were no other signs pointing toward a loose tie-rod ready to turn a front wheel 90 degrees and kill me dead. But, a bad bearing could seize up a tire and that's not good either.
I read up in the Muir book and the Bentley manual about how to check bearings and CV joints and then spent 1/2 an hour yesterday jacking up each wheel, removing it and checking for just those things. From what I could tell, and someone with more experience might give me a better 2nd opinion, all bearings and CV joints seemed just fine. The tie rods were also nice and tight. No play of any sort in any of those systems.
I did find the source of the noise, though, with about 94.32% certainty. On the left-front disc brake the splash guard was a bit bent at the bottom right by the brake caliper. The splash guard is just a flimsy piece of metal on the inside of the disc that keeps water and dirt from getting on it. The dent in it was close enough to the disc that it looked to be touching at first glance. I imagine that while turning right the wheel gets torqued enough to bend the disc into the splash guard that extra couple millimeters to make a "tock tock tock" sound that corresponds with wheel rotation.
After bending the splash guard back away from the disc easily by hand and replacing the wheel I took the car for a 1/2 hour test drive and never heard the noise again! May all your worrisome car noises turn out as innocuous.
posted by Chris Druckenmiller at 7:09 AM
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