Saludos. Just a few days ago I tested the compression of my Vista Cruiser '75. The engine is 445 (396021Fa), and the compression, I think, it's too low. 60-75 psi for each piston. I know since 1973, Olds started to produce low-compression engines, but, I don't have the owner's manual, so I don't know what were the original compression of this engine. Any one knows?

Regards from Mexico.

As you asked it, the FSM will not have the answer to your question. They will only show an allowable difference between the lowest and highest cylinder, and that is only a starting point.

At the time you did the test:

Was the engine at normal operating temperature?
Were all the spark plugs removed?
Was the carb open fully?
Were there four compression strokes during the test of each cylinder?

How many are 60# and how many are 75#.
Show us the readings by cylinder.

1 = ?
2 = ?
3 = ?
4 = ?
etc.

Norm

Saludos. Well, here is some more information:

Was the engine at normal operating temperature? - Yes

Were all the spark plugs removed? - Yes

Was the carb open fully? - No, my bad...

Were there four compression strokes during the test of each cylinder? - Yes

Here are the readings from each cylinder:

1=60 psi

2=55 psi

3=65 psi

4=60 psi

5=65 psi

6=60 psi

7=70 psi

8=75 psi

psi=Pounds per Square Inch

It was a mistake didn't open fully the carb, in some days I will make another test, this time, with the totally opened carburetor.

Regards from Mexico.

Your numbers will be higher. There is no reason for concern, either way.

If it doesn't leak or smoke and all cylinders fire when they are supposed to, relax and enjoy driving it.

Norm

Ok, jaja, now I have another problem, this time, with a light on the instrument's panel. When I turn on the car , the light do it too. The light says GEN... what can be?

Regards from Mexico.

- An excuse, my english is not very well.

I assume that would be the Generator light.

TOC Admin
Brando

The "gen" bulb should light when you turn the ignition switch to "on". This verifies than it is operational. It should go out as soon as the engine starts, showing that the charging system is working properly. It will stay on, anytime the current reaching the battery, is less than it should be.

If the belt is not slipping, your alternator and/or its regulator might be bad. It is possible, a wire or ground connection may have worked loose.

Norm

Hello, In 1975 the 455's with Auto trans, Auto tran/AC, Auto Calif all had 8.50:1 Compression. Hope that helps

Have a Good One

He is in Mexico, and did not say whether it is a CA, or a 49 state car.

The compression reading in question, is the cylinder pressures at cranking speed. Nothing to do with the "advertised" numbers you posted.

Norm