4 replies to this topic

[scerre]

My independent Volvo mechanic told me that my compression is as follows in each cylinder: 160, 30, 110, 180 and 140. The car is a Volvo 850 1995. 2.4 L. He recommends a replacing the engine. I have done work on the car myself and would like to fix it myself. If I were to open 'er up and repair. What would I most likely find?

[MrWinkey]

You need to do a leak down test on cyl #2....or the one showing 30 and it will reveal all ..Possibly a burned valve...From what you state I couldn't condemn the motor?

[scerre]

Oh...I forgot to mention that there is a severe knocking noise coming from the engine. Is that just the difference in compression between the cylinders?

[Bay13]

Thats hard to tell. A compression test should be done with a warm engine and the throttle plate open. Then a second compression test with oil put into the cylinder if you have low readings. Then you do a leak down test like mentioned. After you have all those results, if it looks like it could be a burn valve you can use a boreascope to look into the cylinder to help confirm the burnt valve. If it's a burnt valve then a head job will fix the engine.

[scerre]

Oh...I forgot to mention that there is a severe knocking noise coming from the engine.  Is that just the difference in compression between the cylinders?

So as I understand it...do all the tests for the low cylinders or just cylinder #2? Should I be concerned about the others being low?