Re: Loss Of Compression After Valve Work

Posted by fredkanter On 2017/5/2 20:00:39

.0025 is TWO AND 1/2 THOUSANDTHS, .025 is TWENTY FIVE THOUSANDTHS. Of course that does not explain the compression problem.

A flathead Packard with no engine/valve wolrk in almost 100,000 is unusual.

Here's a story that may explain the problem. My son had a used late model Audi S4, after year of ownership (at 54,000 miles)it refused to start. We checked everything, then did a compression test, most cylinders were between 20 and 40 lbs. This is a high perfromance model which should have 140 lbs. Surely, we thought, our compression gauge was defective. Tested it in my Crown Vic and it was OK. Blew air into the cylinders and it came out both the intake and exhaust.

Tore down the engine, turned the head upside down and poured lacquer thinner into the combustion chambers, in seconds it leaked through the valves. Removed a few valves and found the guides excessively worn. The valves when closed did not center on the seats losing compression.Prior to this the car seemed to have lots of power and ran very well.

The Packard may have worn valves/guides. On the possibility it has a broken cam or jumped timing, in 57 years of working on Packards have never seen either. On the lifters being out of adjustment, the owner stated he removed , disassembled and cleaned the lifters. Therefore they are hydraulics and not adjustable