1955 Cadillac Eldorado has engine knock.

[Barry M Wheeler #2189]

The widow of a good friend is wanting to get her husband's 1955 Eldorado repaired. It runs, but has a knock that gets worse as the car warms up. She is looking for a mechanic in central IN. My own guy is very good, but I'd like a "possible" cause before I go to him and see about hauling the thing halfway across the state.  (He is quite talented, but has the personality of...Well, he always has a blank scowl on his face, so you don't know what he's thinking.)

Any help would be greatly appreciated.

[35-709]

If she's really lucky, it could be carbon knock, saw a fair amount of that back in the day.  GM used to make a solvent for that, poured down the carb, today I believe you would use a Seafoam product.  After that, good likelihood she is looking at an engine overhaul. 

[Barry M Wheeler #2189]

I wrote her to try that first. Thanks. She also has a 1954 CDV, a 1959 convertible and '81 and '91 Fleetwoods. So she's somewhat familiar with the cars. (All"done" except the 1955.) They sold the '53 Eldo.

[bullet bob]

I had a knock in my '53, turned out to be a vacuum leak.....