Originally Posted By: A_Harman
Originally Posted By: dailydriver
Originally Posted By: 69GTX
I consider the PP and QSUD synthetics in the 30 grade a bit weak for an LS-1 that is driven spirited at times.
Yes, I am finding this out the hard way on my current fill/OCI.
I don't know if it is the low SAPS, the GTL base stock, lower grade VIIs (to get it's 0W rating and 204 VI??) or something else, but this oil does NOT 'like' even brief excursions into the upper RPM range.
It is
supposedly a 3.5 or greater HTHSV Euro formula, but the oil pressure is acting like a thinned out 0W-20 right now, after a ~10 minute "Italian Tune-Up" on the highway @5000-5200 RPM.
Could it have sheared down that radically, and aerated that badly (the oil pressure gauge was bouncing down lower than it has EVER been since owning this car new at stop light idles after this highway run) just from this short high(er) rev use???
I am ready to dump this stuff and put in Red Line 0W-40, or 300V 0W-40, winter ambients (IF we ever actually get them) be D***ED!
Try changing out the Fram Ultra filter to a Bosch Premium. I changed from a Fram Ultra to the Bosch Premium a couple of oil changes ago, and the oil pressure went up.
I DID change out the Ultra to an Amsoil EaO 64.
The needle on the gauge STILL 'twitches' well below where it was with ANY other oil/mix I have ever used, at hot idle.
WHAT are the symptoms of a worn (gear teeth?) gerotor type LSx oil pump, or of a broken/worn spring in the pump's pressure relief valve??
How likely is it (given the engine's mileage) that my Italian Tune- Up hurt the pump, or the relief valve?