justin hover

So when the trans was out we noticed a leak by the opsu. So we replaced it. Before with the stock opsu my pressure would be in the norm 48-34 cold/hot. Now while driving its 40/or 35 but when I come to a stop and idle it drops to 25/20. Should I worry? replace? or leave it for now?

AmDWs6

normal is @idle slightly above 40 never lower. so yes,yes & no.

Crimsonnaire

iTrader: (1)

There are two points at discussion here which should not confused with one another: first, what the optimum oil pressure is, and two, what your oil pressure actually is. Since your pressure dropped immediately after replacing the unit, it is logical to assume that the higher pressure was your actual pressure (since damaged units will only operate at lower efficiency) and that your new readings are inaccurate. You can have your actual pressure tested at any professional shop for a very reasonable fee or you can do it yourself with the proper equipment.

Concerning optimum oil pressure, my past research has led me to understand that, with these cars, the pressure level will vary per many different variables, i.e. bearing tolerance, oil grade, filter brand, oil pump condition, efficiency of cooling system, etc. Thus, it can never be said that your pressure 'must' be this or that, but rather determining whether your pressure is appropriate for the collective circumstance of your vehicle.

justin hover

That's kinda the conclusion I came up with. All I know is before it would for the most part run at 38-42 no matter the temp , idle, or accelling. Now it runs 25 at idle and 40 during crusing. Some threads say its normal, some say its not. If the 10lbs/1000 rpm rule is still in effect I should be fine.

wssix99

iTrader: (5)

What brand of OPSU did you replace the original with?

Black01Bird

10/1000, or ive also seen 20/hot idle is when you start worrying.

Mine is around 55 cold idle, 38-42 hot idle, cruising at 1000rpm or so its at around 40-42, and cruising at 2200rpm or so is between 50-60

SiggyBaby

I'm getting the twitchy needle on my oil pressure gauge when I'm sitting idle at a light. The pressure isn't too low (sits just above 40psi), but the twitch annoys the hell outta me.

justin hover

IDK...I had left the shop knowing it needed to be replaced. I figured it was the oem gm version they were replacing it with. But it was another brand, supposed to be a better one. It cost 60$ and I forgot the name of it. I'm slightly pissed..I'm wondering if the new unit is too much. I'm gonna wait until this cam install is done this week and see if the problem persist. If it does, they can replace it with the oem gm opsu. It just never dropped off to 20-25 before the new unit. And its only 45 degrees out.

wssix99

iTrader: (5)

I'd check the brand. I went with an off brand and the new one read low and was jittery. After putting in a GM unit, life has been much better:

https://ls1tech.com/forums/general-m...ding-unit.html

justin hover

Was it the ac-delco gm sending unit? Just so they get it right this time.

wssix99

iTrader: (5)

You know - that's a good point. (GM And AC Delco are not always the same.) My latest try is:
AC Delco Oil Pressure Switch D1818A (19244505)

I recall that I looked this up in the GM parts list and found this AC Delco unit listed as the original equipment.