Compression problems

1965 FORD THUNDERBIRD
70,000 MILES • V8 • 2WD • AUTOMATIC
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ERIC THE BARBER
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  • 1 POST
I recently bought a 65 Thunderbird. It sounds like its missing or I have some bad compression somewhere. What is the best "backyard mechanic" way to determine where the bad compression is?
Apr 24, 2011 at 2:40 PM
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CARADIODOC
  • Experienced Mechanic
  • 34,367 POSTS
Check at the auto parts stores that borrow or rent tools to see if they have a cylinder leakage tester. You put each piston, one at a time, on top dead center on the compression stroke, then pump in compressed air through a gauge. The gauge will read the percent of leakage, and you can listen at four places for the source of the leakage. Tail pipe: burned exhaust valve. Carburetor: burned intake valve. Oil cap or dipstick tube: piston rings. Radiator bubbles: head gasket or cracked head.

They also make a whistle that screws onto the tester's hose that makes finding top dead center real fast and easy. You crank the engine by hand with a socket and ratchet, and as the piston slowly comes up on the compression stroke, the whistle will let you know you're there when it stops whistling.
Apr 24, 2011 at 3:01 PM
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CJ MEDEVAC
  • Experienced Mechanic
  • 11,004 POSTS
This is an inexpensive set, pretty much all of the Normal Stuff you will need to test/ adjust/ and tune an older vehicle (even on some of the newer cars too)

The cool thing is, it's all in one Compact Case, and less than $40 at "Harbor Freight".....A voltmeter is another item you should have, same place, $7 and under!

If you are gonna continue to work on this vehicle, each of the Items will make things EZer for you--decent instructions within!

We can help you figure things out too, Just continue to ask, here at this question!

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The Medic
Apr 24, 2011 at 3:52 PM
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