zreader

have a 96 silvia k's, sr20det, also probably relevant, the car has an hks r-type oil cooler with filter relocation. did my first oil change since getting the car and ran into an odd issue...

if i've read correctly, an oil change should be about 3.7L of oil, and the oil cooler system could be another 0.5 to 1L or so all by itself, so i was expecting to drain 3.7-4.7L of oil. only about 2.2L came out...

ill describe my process, hopefully someone can let me know where i've gone wrong or what im missing. first i fired up the car and let it run for about 5 min to let it warm a little bit as i drove it up on to ramps and then jacked the front of the car up and placed the jack stands. my understanding is that this to warm up the oil and so it thins out and flows easier when draining. maybe i could have let it warm up to operating temperature? idk?

after shutting it off, i opened the fill cap then got under the car and undid the drain plug and oil filter and let it drain for a bit until there was a very slow drip. proceeded to jack up the rear of the car to get it even, it drained a little more for a bit until a slow drip again, lowered the rear and brought the jack over to the side opposite the drain hole and lifted that side and a little more oil drained out for a bit until a slow drip again. overall it was draining for a good bit of time, idk 15-30 min?

i actually contacted hks since i've never owned a car w/ an oil cooler before and it came on my car, they advised that the oil change process doesn't change and the oil cooler drains into the sump anyway.

anyway i proceed to put in the new oil filter and oil drain plug and put in some fresh redline 10w50. after 3 qts, or about 2.8L i decide to check on the dipstick and wtf its way over the H line! how can this be?? by the way i also confirmed w/ hks that the oil cooler and filter relocation kit won't affect my dipstick reading so that should still be reliable, but i should need to add about 0.5-1L more oil than standard.

at this point thinking through the process i go ahead and check out how much oil came out and discovered only about 2.2L was drained. even if i had let the car sit for another day i don't think im going to make up that 1.5 to 2.5L of oil...

anyways that's my saga. its my first SR20DET, my first car w/ an oil cooler on it, so im definitely a noob in a couple of ways and i dont want to f this thing up. my expectation going into this was that it shouldn't be any different from any other oil change i've done, but something is definitely not right here, or maybe it's just been too long since ive last done an oil change (it has been a long time) and hopefully it's something obvious.

thanks for reading! please help!