Z24 Compression

[85"720]

I did a compression test on my truck and this is what I got

Intake#1 160psi

Intake#2 165psi

Intake#3 155psi

Intake#4 165psi

Exhaust#1 120psi

Exhaust#2 103psi

Exhaust#3 130psi

Exhaust#4 120psi

My question is shouldn't the exhaust side be almost the same as the intake or is this normal. Motor has 130k original miles

[datzenmike]

Yes they will be identical.... so your method is wrong somehow. Warm the engine to operating temperature and be sure the other plug is in snugly. You only need to do one hole per cylinder. If the rubber end type that you push and hold, be sure it is securely held and no compression escapes. If the screw in type be sure it is in a tight. Take two or three readings and average them. They should all be within a pound or two or the compression tester is faulty.

 

I wouldn't do a compression test until all the valve clearances are checked.

[flatcat19]

Did you do the intake side first?

 

Maybe by the time you got to the exhaust side your battery was starting to feel the burn. 

Put a charger on it to keep a consistent voltage while performing your tests. 

[85"720]

I did the exhaust side first the other day and did the intake yesterday. I did it on a hot engine both times. I did one plug at a time. I still need to get them adjusted. So both sides should read identical then?

[datzenmike]

Yes they will be identical.... so your method is wrong somehow. Warm the engine to operating temperature and be sure the other plug is in snugly. You only need to do one hole per cylinder. If the rubber end type that you push and hold, be sure it is securely held and no compression escapes. If the screw in type be sure it is in a tight. Take two or three readings and average them. They should all be within a pound or two or the compression tester is faulty.

 

I wouldn't do a compression test until all the valve clearances are checked.