Hey John:
It sounds like your old unit is a high quality compressor. They are really quite simple to take apart and look inside. I'll bet you'll be able to visually see the problem. Case in point: My compressor, very similar to yours developed a terrible knock after running for a minute or two. I was sure it was a connecting rod bearing. I dumped motor honey in it, noise persisted. Finally took it all apart, found nothing wrong except a loose flywheel. Reassembled it with lock tite on the flywheel and it runs like new.
If you are faced with buying a new one, as stated, avoid direct drive oiless diaphragm type compressors, they are VERY noisy and have limited output. Belt drive, two stage, no less than 8 CFM at 100 Lbs capacity will do the job. Look around for used in the paper, at auctions, and shop sales. Good Luck, see you in G.R.
Mike Kurta
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