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Cadillac & LaSalle Club Forums => Technical / Authenticity => Topic started by: Julien Abrahams on April 08, 2025, 01:18:24 AM

Title: Strange noise after cold start ('66 Eldorado)
Post by: Julien Abrahams on April 08, 2025, 01:18:24 AM
A friend of mine has a '66;Eldorado that I got running and driving last year after being in storage for almost 30 years.Car runs well, but now has developed a strange noise that appears sometimes after a cold start. It goes away after about 5 mins of running.
He made a video for me to have a listen. I find the noise pretty strange. It is a california car, so it has the A.I.R. system. What could this be?
Title: Re: Strange noise after cold start ('66 Eldorado)
Post by: "Cadillac Kid" Greg Surfas 15364 on April 08, 2025, 10:29:06 AM
With the AC on or off?
Greg Surfas
Title: Re: Strange noise after cold start ('66 Eldorado)
Post by: Julien Abrahams on April 08, 2025, 10:52:00 AM
The AC is off. The AC is most likely not charged anymore, and compressor is not locked. I believe the compressor electrical connection is disconnected.
Title: Re: Strange noise after cold start ('66 Eldorado)
Post by: Jeff Rosansky CLC #28373 on April 08, 2025, 10:54:18 AM
I don't see a video, but what does it sound like? Ticking, rubbing, buzzing, hissing?
Both sides, front/rear?
Title: Re: Strange noise after cold start ('66 Eldorado)
Post by: Julien Abrahams on April 08, 2025, 11:16:20 AM
I reposted the video, so hopefully it works now.
It is more like a swooshing, grinding noise. Hard to explain.
Title: Re: Strange noise after cold start ('66 Eldorado)
Post by: "Cadillac Kid" Greg Surfas 15364 on April 08, 2025, 11:30:31 AM
From what I hear Just sounds like a motor with a few miles on it warming up.
Greg Surfas
Title: Re: Strange noise after cold start ('66 Eldorado)
Post by: Cadillac Jack 82 on April 08, 2025, 12:21:10 PM

Sounds almost like the fan blade striking the radiator.  That's definitely not an engine noise.
Title: Re: Strange noise after cold start ('66 Eldorado)
Post by: TJ Hopland on April 08, 2025, 12:26:01 PM
I would agree, not an internal engine issue.  Frequency seems a little high but how about the 'heat riser' valve?
Title: Re: Strange noise after cold start ('66 Eldorado)
Post by: Big Fins on April 08, 2025, 03:23:02 PM
Disconnect the belts one at a time and listen to it. That sounds like an alternator bearing or water pump bearing. Does it have an A.I.R. pump on it?

The engine itself sounds normal. I wouldn't touch that. It's an accessory or maybe even the torque converter, by the whirring sound it makes.
Title: Re: Strange noise after cold start ('66 Eldorado)
Post by: Michael Petti on April 08, 2025, 08:30:40 PM
Just a thought, but could your fan blades be hitting the transmission cooling lines when cold?
Title: Re: Strange noise after cold start ('66 Eldorado)
Post by: Julien Abrahams on April 09, 2025, 01:21:01 AM
Good suggestions that we can try. After listening a couple more times I also was thinking something in the line of bearing issue i the A.I.R. pump. Removing the belts one by one would be a good way to isolate the problem. Not sure about the fan blades.How to check if it is coming from the torque converter?
Title: Re: Strange noise after cold start ('66 Eldorado)
Post by: Michael Petti on April 09, 2025, 06:08:23 AM
The tranmission lines and/or their metal ends will show wear spots.