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Discussion Starter #1
ok guys i did a compression test when i first started working on my car, but i did not start my car and let it run a little before i did it i was told i could do it cold, well tomarrow i plan on doing it again. but the first time i did it was i got 124 on cyl 1 and the rest were in the 140's. so i called up a shop here in town and they said it was good. but every one is telling me its the rings. but when i redo the test i will let the car run a little before doing it. but lets say the one cyls is 125 do i put a little oil in it and see if it raises it and if it does what does that mean??????
 

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Thats Pretty Low, I'm Pretty sure its an old oil burner engine. Pour some transmission fluid or oil in the spark plug holes and unplug ur distributor and turn the motor over a few cycles with no plugs in motor then redo the test.

If the results are higher then u have worn piston rings and a overhaul is need soon.


Hope This Helps.
 

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hey man how much oil should i put in??? i know if i put to much in then it will brake my rings. but whats the wright amount??? and how man times should i turn it over??
 

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OK here is the DEAL. First make shure you ground the coil wire before testing or you will FRY the TFI module. Any time you put oil in a cylinder the compression will come UP. Even if there is a valve problem. The oil makes the rings seal better NO MATTER WHAT. Also it does not test for bad OIL rings. The difference between cylinders should not EXCEED 10% so the lowest number should not exceed 126 LBS. If the good cylinders are 140 LBS. Always test with a worm engine. I think you will find that the compression may not be your problem. Basically a compression test is useless unless the numbers are real low and you will know that before the test BELIEVE ME. The best test is a leak down test to find out if the rings are BAD Hope this Helps peace Tom

Have You driven A Ford Lately???
 

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Discussion Starter #5
hey man i thought a leak down test was you put oil in the cylinder???? so by me puting a little oil in the cylinder and then redoing the compression test that will not tell me anything?????
 

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Not really but do it just for a learning experience. All the cylinders will come up. If you have a valve issue a leak down test is the way to GO. A leak down test is a device that shows the percentage of leak the cylinders have. Its done through the spark plug HOLE with a lead down tester. It actually fills the cylinder with shop air and reads the % of leak DOWN. That is the best test. A compression test is OK but its not the WHOLE story. My GUT feeling is your compression is OK according to your readings. Hope this Helps Peace Tom

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OK do this. Worm the car UP to operating temp. Pull the plugs and do a compression test. The throttle must be wide open all plugs out and crank each cylinder at least 10 times to get an accurate reading in each cylinder. Record the numbers. Then squirt some oil in each cylinder APP 3 pumps from an oil can in each cyl. Then crank the engine to mix the oil up in the cylinders. Then test and post both readings. The dry readings will be lower on all cylinders and the wet will be higher. The rule of THUMB is they must be within 10% of each other. Do it and post back. Then we will have a set of numbers to analize. Remember crank each cylinder APP 10 times and ground the coil wire. Peace Tom

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Before you worry yourself to death with the rings, there are other parts of the engine that may affect compression. That's why a leakdown test is a good companion to the compression test. The leakdown test can help determine where your cylinder pressure is being bled off.

Pressure up the cylinder with compressed air. Take off the radiator cap, and the oil cap. Listen for the hissing sound of air escaping. It'll either be bubbling out of the radiator (blown head gasket) hissing out of the oil fill hole (bad rings, or blown headgasket), hissing out of the exhaust pipe (worn or burnt exhaust valve), hissing out of the intake (worn intake valve or valve seat).

This doesn't change the fact that you'll have to tear the motor apart to fix it, it just tells you where, and how far you need to go. Happy hunting
 

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Discussion Starter #10
ok i will do that all tomarrow, i dont got a leakdown tester but i found some one real close that would do it for $30.00 at his shop, plus its close by because the car is not lisenced yet LOL, but i called summit to day and they got a master rebuild kit for 330.00, this is the cheapest i have found, but i also called a machine shop to day to have them redo my head and its 2-300.00 dose these prices sound fare??
 
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