I brought my 67 Eldorado home from the restoration shop yesterday only to find out that the AC compressor died and leaked the fresh refill it got. Everything is new except the compressor and of course it died at the first usage. The system was pressure tested at the shop and worked like a charm. When they let the car idle with the AC on, the compressor started to leak. They tried to fix it but had no success. So I will need a new compressor and a new charge.
The right headlight door actuator also suddenly no longer works correctly. All hoses are new and it worked perfectly until recently. I can now only make it close if I jiggle on the actuator. Is there any way to rebuild them? A source for new or rebuilt ones? I have heard that the ones from the 1969 Camaro is very similar and only needs some minor modifications to work on the Eldorado as well. So I went ahead and ordered one. But the worst thing was that the freshly rebuilt carburetor made strange ticking noises and sounded like a tractor while accelerating. It worked well though, but the sound was unbearable. Could it be a defective gasket? It was also idling quite badly. Acceleration was superb though, its much more powerful than before, but still something was wrong... The ignition also was completely rebuilt. So I played around with the ignition first, but the ticking sound did not go away, no matter in which direction I changed the timing... Almost sounded like an exhaust leak, but there seemed to be none... I´ve uploaded a soundfile of the carburetor while idling. http://www.speedometerfilm.com/carb.wav It was recorded with my phone, so the sound-quality is not the best, but it should give you an idea. The phone was about 20cm away from the carburetor while recording. It was LOUD! Before I had the carb and ignition rebuilt, it was extremely quiet and idling smoothly but had misses while accelerating.
I got some very valuable tips from fellow Cadillac aficionados and the previous owner of this Eldorado even called me from the USA to give me some tips to solve this issue, and he was spot on with his diagnosis...

With a hose held to my ear and the other end to the carburetor, I was able to locate the source of the noise. It came from the carburetor below the choke assembly. So I took the freshly rebuilt Rochester Quadrajet out again, only to find out that the gasket and the metal shim were installed the wrong way around. This burned a hole into the brand new gasket where the exhaust gases from the heat crossover passage could escape and make this noise.
Of course I did not have a new gasket at hand, so I carefully removed the old one from my spare engine, which was in pretty good shape and installed it.
No more ticking - no more noises, no more bad idling.
The car now drives amazingly good and is silky smooth. It could not be any better.

the shim was installed first and then the carb - thats wrong! The gasket has to go on the intake manifold first - then comes the metal shim.


here you can see the burnt gasket and the metal shim


putting everything back together again


test drive after the repair - perfect!

Tags:1967, Eldorado, Restoration, Carburetor, Rochester, Quadrajet, Headlight doors, Headlight Actuator, AC Compressor, A6