"danielr" > wrote in message
...
> 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

And thank you 'Private' for your input also.