58 caddy breathes heavy
 

Can anyone help with this as not a great machanic. It breathes really badly and smokes out of the breather when you drive it. Need help please. Stewart

any background on this 1958 car? not enough details to provide logical help.
read our thread of TECHs are here to help
https://www.cadillacforum.com/forum/...ead.php?t=3156

but

based on the one comment, I be doing a COMPRESSION TEST and then report back.

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Disconnect the coil wire.
Cover coil with plastic bag and clean engine, specially around spark plugs.
Remove plastic bag from coil, leave it disconnected
Battery must be fully charged .. if cranking "slows", stop and recharge battery before continuing.
Hold the throttle wide open.
put transmission into neutral
Chuck the wheels
Remove all Spark Plugs.

plug in compression tester on cyl #1
Crank the starter for about 5 to 7 compression strokes (you can see the gauge move UP 5 to 7 times).
write down the highest number on gage
repeat last two steps for each cylinder

if the numbers are below 140, read below.


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most engines in great condition will have 140 to 160 lbs. of cranking compression with no more than 10% difference between any of the cylinders.
Low compression in one cylinder usually indicates a bad exhaust valve.

Low compression in two adjacent cylinders typically means you have a bad head gasket.

Low compression in all cylinders would tell you the rings and cylinders are worn and the engine needs to be overhauled.

If compression is low in one or more cylinders, you can isolate the problem to the valves or rings by squirting one ounce of 30W motor oil into the cylinder through the spark plug hole and repeating the compression test.
The oil temporarily seals the rings.
If the compression readings are higher the second time around, it means the rings and/or cylinder is worn.
If the compression readings dont change, that tells you the cylinder has a bad valve.


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Thanks for your time, i will try this and thanks again. Stewart