Today we got a chance to replace my plugs and wires w/ Autolite copper plugs and my lifetime warranty wires. Did a compression test on the engine. Here's what it pulled:
cyl 1: avg 162.5 PSI
cyl 2: avg 150 PSI
cyl 3: avg 162.5 PSI
cyl 4: avg 175 PSI
cyl 5: avg 175 PSI
cyl 6: avg 160 PSI

are these good #'s?

 

I would be worried about that one that pulled a 150. Their is total of 25psi difference their. I was told their should be no more then 10psi. Thats just what I been told.

 

The thing is, there ain't much you can do about compression with out going into the engine. Some additives clame they help the valves seal but... One test you can do is to put some oil into the spark plug hole, let it sit for a few hrs. do a compression test- if the pressure goes back up, its the rings leaking, if it doesn't it's the valves. If the engine is running good with X number of miles on it, I wouldn't go digging in it's "inner'ds".

 

Those are great numbers.
Your engine is still sealed very well.
My recent 3.4 registered 150psi all cylinders (+/-).
And this is a supposedly 50K mile motor. I believe so.
My 44K motor in the Firebird was 175-200psi all cylinders.
Find the tapping noise yet?

 

Yea the noise is coming from the dirty lifters. I poured in some CD2 oil detergent this morning, I'm probably going to use tranny fluid next time. I'm going to need more, so I'm going to wait until it burns off before I add more.

OOO, I typed in the wrong pressure for a bunch of these. I was working off memory

#2 - 160 PSI
#6 - 150 PSI
#5 - 155 PSI

all the rest are correct

 

Comparison
My 211,500 miles 2.8 in my 1985 Blazer?
I was able to get 50 lbs after I did the head swap because of bad head gasket

 

I thought it was supposed to differ by not more than 10%, instead of 10 PSI? But either way, those numbers look good. I thought I put my compression test #s up, couldn't find the message thru a search, but I had 5 cylinders between 140-160 PSI, and one "dog" at 135 psi. (This was the cylinder that had a damaged spark plug due to detonation from over-advanced timing, oops.) Carbon buildup (on the top of the piston and in the combustion chamber) can also increase compression test #s. The "fix" is to clean the chamber out with water. You fill a spray bottle with water, run the engine with the intake hose disconnected, and spray a "mist" of water in front of the intake hose. Supposedly the water mist gets sucked into the intake tube and breaks up the carbon - like a steam cleaning. Just don't fill your engine with water, of course, or you'll hydrolock

 

Tom,
I was wondering if anybody did that "water mist" thing with fuel injected engines!
R.J.

 

We use a drip system to break down carbon build-up. It's a little can that we hook up to manifold vacuum and it drips GM top engine cleaner into the engine. The drip setup can easily be built at home.

In cases where we suspect a sticky valve or something carbon related, we'll actually dump top engine cleaner in the throttle while holding the engine around 2500 rpm. The engine eventually stalls and then we let the cleaner soak for about 30 minutes. Sometimes it works...and sometimes it doesn't.

 

You let it soak for 30 minutes?!?!
Lot longer than the can says.
I've used that stuff and man does it clear out the old lungs.
How do the fumes exit?
Hoses out closed doors?

 

Hehe, when we do this (not very often) , it's always outside. After it soaks, we start it up and there is a HUGE cloud of smoke. HUGE.

 

I occasionally do the steam cleaning thing too, but I can't see how it's good for my cat......luckily C_CHotrod hooked me up with a free cat though, I just haven't gotten around to putting it on...especially considering I'm thinking of selling my car.

 

So now I have carbon build up? Now isn't that nice...
OH, With these #'s, why do I burn like 1 quart of oil every 3000 miles?

 

What's the problem?
Quart a 3,000 miles is perfectly normal.

 

Might have worn out valve seals, and you're burning oil that drips down the valvestems and finds its way into the combustion chamber... what weight oil do you use?

 

10W-30, Valvoline Maxlife is currently in there. Everything from Pennzoil 20w-50 to Mobil semi-synthetic 10w-30 has been in there.