Results from my compression test

[strongboy2005]

I think the numbers speak for themselves:

Cylinder 1 - 190 psi
Cylinder 2 - 135 psi
Cylinder 3 - 150 psi
Cylinder 4 - 170 psi

The car in question is a 1999 Chevy Metro Lsi 4-door sedan, 1.3L inline four. These were my results for the compression test I just did. I'm wondering, is this normal for an engine with 86,000 miles on it? Should I be worried about such huge differences in the data? ...or is it time to sell my car...

Any help would be greatly appreciated...

[Blue Bowtie]

The difference (in percentage) is more important than the actual numbers. You have a large variance with #2 and #3, so make sure the valves are closing fully. you can try injecting a couple ounces of clean engine oil through the spark plug hole and repeat the test on the low cylinders. If compression increases, that can indicate waorn rings. If compression remains the same, that can indicate leaky valves, or possible mechanical damage to heads, pistons, or cylinder walls. Given the relatively low mileage, I would tend to think it is a valve sealing problem.

[Teal95Jimmy]

If you notice it is adjacent cylinder so it could be a head gasket problem too.

[strongboy2005]

I redid the tests after adding a cap-full of oil to each cylinder.

Cyl 1: 265
Cyl 2: 260
Cyl 3: 280
Cyl 4: 295

Cylinder 4 actually ended up getting half a cap of oil more than the others, and my buddy is unsure if the first two were completely "done". Nevertheless, they all seem quite a bit higher than the compression numbers I got earlier.

[534BC]

Wow, that's a huge increase. Blue gave you perfect advise. Rings, rings rings.

You may also test the blow by by removing oil cap and revving engine. The engine seems very worn out to me.

[silicon212]

I would almost suggest, due to the cylinders most affected (2,3) that there's a head gasket failure between cylinders.

[BlazerLT]

http://www.auto-rx.com/rms13/about.htm

Try Auto-RX.

It will release your rings. This has been proven to work time and time again.

Check out his tests and they have been verified.

[534BC]

Originally Posted by silicon212

I would almost suggest, due to the cylinders most affected (2,3) that there's a head gasket failure between cylinders.

That may be a good guess especially if the cylinders are siamesed, does anyone know? Adding oil probably will not help a gasket.

Something about those compression numbers just doesn't seem to be consistant. How about trying a leak-down test?

[BlazerLT]

http://www.auto-rx.com/rms13/stats.htm

[corning_d3]

Just pull all the spark plugs, put the cylinder in question on TDC, and put shop air into the cylinder thru the plug hole, and then listen to where the air is escaping. Listen to the intake(Intake valve), exhaust(Exhaust valve) and the dipstick tube or oil fill cap(Rings), and lastly the adjacent cylinder plug hole(Head gasket).

[534BC]

Originally Posted by corning_d3

Just pull all the spark plugs, put the cylinder in question on TDC, and put shop air into the cylinder thru the plug hole, and then listen to where the air is escaping. Listen to the intake, exhaust and the dipstick tube or oil fill cap, and lastly the adjacent cylinder plug hole.

That's a " " leak down test.

[corning_d3]

I know, I was just explaining how to do one since no one else did...

[534BC]

I was just razzing you anyways. I had a lot of spaces in between quotes and was afraid to offend certain groups so choose what ever you want to put in-between.

Your tips are great.

[corning_d3]

Hehe, i figured you were only kiddin' around. I'm not at all easily offended anyway.

[strongboy2005]

Wow that Auto-RX stuff is like $20 a bottle... Do any places sell it (Autozone, Kraigen, Pep Boys) or do you have to buy it online?

Is there anything similar to Auto-RX that could get the job done for cheaper ($20 for a 12 oz oil additive!?)

Thanks for all the replies.