Compression Test *Update*

[Jack's Dodge]

Just did the test again and numbers came up a bit different : 155 - 260 - 300 - 160 . So check to make sure I did it once more just for kicks : 155 - 220 - 240 - 150. It seems #2 , #3 may still have some oil in there. It was synthetic if that makes a difference Seeing as the head checked out "ok" after being pressure tested, I'll put it all back together.

[SilverShelbyZ]

Carlton, I think that's a good idea.. Ideally you should do the test with the engine somewhat warm and with no oil in the cylinders.

[turbovanman]

I'd try a different guage, I think its off/not accurate!

Synthetic oil won't make a difference!

Yeah, no way it's making it over 200 no matter what unless you got dome pistons LOL.

[Jack's Dodge]

Believe me, it is obvious the numbers are high. There are dozens of possiblities, but there is only one way to find out. Put it back together, and let it run for a while. The numbers for #1 and #4 came down considerably, and I believe the the remainling cyl will as well.

[Jack's Dodge]

Quote:

Originally Posted by SilverShelbyZ Carlton, I think that's a good idea.. Ideally you should do the test with the engine somewhat warm and with no oil in the cylinders.

Not much left to do but run the vac lines, and fill 'er up with coolant. Might do that tomorrow, so I can focus more on the brake lines. Called inline tube for a catalog. That is the next obstacle before my daytona can be road worthy :banaride:

what i do is test cold and then you can tell if you have a cracked piston or what because when the engine is warm the pistons expand and can close a crack that way do a cold test that way if theres a crack the gases will escape under the piston there for you will have a lower compression reading and you can telll what cylinder is yer problem

[Jack's Dodge]

Quote:

Originally Posted by shawny2087 what i do is test cold and then you can tell if you have a cracked piston or what because when the engine is warm the pistons expand and can close a crack that way do a cold test that way if theres a crack the gases will escape under the piston there for you will have a lower compression reading and you can telll what cylinder is yer problem

Good idea. Though the car has not been started in almost a month, so these tests have been done under the coldest conditions.

[turbovanman]

Quote:

Originally Posted by shawny2087 what i do is test cold and then you can tell if you have a cracked piston or what because when the engine is warm the pistons expand and can close a crack that way do a cold test that way if theres a crack the gases will escape under the piston there for you will have a lower compression reading and you can telll what cylinder is yer problem

A cracked piston is a cracked piston, heat or cold will not change that or make it "seal" up.

[Jack's Dodge]

They looked ok when the head was off.

Most of the time it's just the ringlands that crack, sometimes the piston skirt. If you can see a cracked piston from the top with the head off you got MAJOR problems.