Hello all,

I have a 1988 740 turbo with b230ft engine and around 232,000 miles on the odometer. So I did my first compression test today and just wanted to post the results to see what, if anything, people here think about them. The test was done as stated by my Hayne's manual.

approximate numbers in psi:
Cylinder #1 130. #2 140. #3 130. #4 135

after adding a teaspoon of oil:
#1 145. #2 160. #3 165. #4 hard to get to so I didn't check with oil.

The numbers I got are barely within the specifications in my Hayne's manual but just wanted to know what you all think they mean. Or maybe better stated: What would you do if you found these numbers in your Volvo.

A question: Do I just put the spark plugs back in and drive?
I ask this because of the oil added and my manual does not specify.

Any input or anything really is much appreciated. Also if this is a vague or pointless post I apologize.

Thank you,

Benton

My 1983 240, with B23F at 280,000 miles (all original, head has never been off) gives 140, 130, 135, 140.

My 1986 240, B230F at 350,000 miles (new head gasket and valve job at 250K) gives 150, 155, 150, 155.

Keep in mind, though, that naturally aspirated (non turbo) motors have higher static compression ratios than turbocharged motors.

I wouldn't worry about this too much IF your engine runs well and does not use more than a quart or so of oil between oil changes. Higher numbers with the introduction of oil does indicate some ring wear, but you can probably get another 50K (maybe 100K) out of this motor. I wouldn't be a in rush to tear it down.

"A question: Do I just put the spark plugs back in and drive? " -- that's it. Variation between gauges could explain the slightly low numbers (was the engine warm, did you crank it enough times, throttle open, etc?). The rise in compression with oil was minimal. If your engine runs well, doesn't burn oil and you get normal gas mileage you don't have a problem. -- Dave

Thank you for your response,

The engine was at operating temperature when I started. I gave it 4 cranks each time. The peddle was pushed to the floor while cranking the engine. The gauge I'm using is a cheapo one from autozone I just bought.

Yeah I get, with mixed driving, 25 mpg and I am happy with the way the engine runs.

Burning oil: I don't know what the cause is but when I open the oil fill cap after driving there is a kind of white smoke. Not pouring out but is certainly noticeable.

Thank you again for your response, I do appreciate the input.

Benton