Compression test results??? Help

[Spieler209]

Okay so, we ran a compression test on the car and we got 125,125,125,135,125, ---- First off what is normal? and what are your opinions to increase...The car is not burning any oil but is idle"ing like complete shit..Car has 160K miles and contemplating full swap or rebuild..

thanks,

David

[Spieler209]

Will a valve adjustment help these numbers?

[MrWizard]

Normal for an M20B25 is about 150. Your compression is even enough so you may have nothing to worry about at all (even very high dollar compression gauges will vary by as much as 10 psi).

Are you having any issues like oil consumption?

[jlevie]

Those numbers are on the low side, but not unreasonable for a 160k engine. The rough idle is most likely due to causes other than the compression results (intake leak, misadjusted valves, aged plugs, wires, rotor/cap, bad AFM, fuel delivery problems, etc).

[MrWizard]

Those numbers...

I have always admired you jlevie. You're most always right on the money and do a good job of covering the bases even with little info to go on.

Just wanted to let you know that.

[Spieler209]

Options

If it was up to you---Would you do a rebuild at this mileage? or should it be fine for another 60k?? with major tune up and adjustment etc.. Just want to place my money wisely at this point.

Thanks,

[Hick]

check or vaccume leaks, bad temp sensors, or clogged ICV. the compression is not the right thing to be checking for a poor idle.

as long as it dosent vary too much, 125 125 60 125..., then your fine.

[MrWizard]

If it was up to you---Would you do a rebuild at this mileage? or should it be fine for another 60k?? with major tune up and adjustment etc.. Just want to place my money wisely at this point.

Thanks,

Only if there were oil control problems.

[Spieler209]

Thanks for the feedback..