On Feb 8, 3:46*am, "Private" > wrote:
> > "danielr" > wrote in message
> ...
> >> I ride a 1997 SL SOHC, 185.000 Km, standard transmission.
> >> Oil is changed every 3500 Km, I use Castrol Synthetic 5W30, and K&N
> >> oil filter.
> >> I know; some of you might believe it is a waste of money; but I am a
> >> FIRM believer of preventive maintenance.
> >> I am VERY satisfied with this car.
> >> Question:
> >> Which should be range (max / min) of values resulting in a compression
> >> test for this engine?
> >> Thanks in advance for your assitance.
> >> Regards,
>
> >> danielr
>
> "Oppie" > wrote in message
>
> ...
>
> > Rule of thumb is 125-150 psi depending on the compression ratio of the
> > engine. Make the compression test with all plugs removed, the ignition
> > coil disconnected and wide open throttle. Crank for 5 seconds to get a
> > stable reading. Log readings, do all cylinders and then repeat. Make sure
> > you get consistent readings on each cylinder. *Readings between all
> > cylinders should be within 5-10 psi. If you get a cylinder that reads low,
> > put a couple of squirts of oil into the cylinder and repeat the test. If
> > the reading comes up, most likely worn piston rings. If the reading stays
> > low, could be head gasket or valves. Don't forget to label the plug wires
> > as you remove them to make sure they all go back in the right places.
>
> @278,000 km my 96 SOHC 5sp pumped to
> 155 lbs dry and warm, and 230-270 lbs with oil added,
> (the 230 cylinders had less oil than the 270 ones.)
>
> Adding more oil will seal the rings better but will also raise the
> compression ratio, I should have measured the added oil better by counting
> the oil can squirts and adding the same number.
>
> Previous test @178,000 km pumped 130/128/131/130 warm and 128/126/128/125
> cool and 220/185/225/215 oiled warm and 190/155/185/185 oiled cool. *The
> center cylinders were retested 1,000 km later both 160 psi warm. *I suspect
> a piece of crud on valve in #2 cyl during first oiled test.
>
> YMMV depending on accuracy of your gauge, I think mine is OK and was top
> quality and quite expensive in its day but is about 35 yrs old. *As Oppie
> topposted, your results are probably more important relative to each other
> cylinder after dry and wet testing, as these results will all be with the
> same tester. *Record your results in your maintenance log and then you can
> compare them in another 50 or 100,000 km to detect any trends.
>
> Many mechanics will debate the value of compression testing and will often
> advocate for a cylinder leak down test as being a superior test, but a plain
> compression test is easier and uses simpler tools and will quickly find
> large problems like one bad cylinder or valve.
>
> Good luck, YMMV, make sure you have locked the throttle butterfly valve in
> open position for test, IMHO warm is best for reliable results and
> consistency.- Hide quoted text -
>
> - Show quoted text -

Hi "Oppie"

Thank you very much for your help.
Regards,

danielr