How much oil pressure does the common turbo 3.8 hold? I recently purcassed a 87GN and was wondering how much oil pressure it should hold.The engine holds 18 to 22 at hot idle(800rpm) and I use Mobil 1 synthedic 10W30 oil.
Tim, that pressure sounds real good. If it were higher than say 25psi, or lower than 12psi...then I might be a bit concerned.
Yours seems to be very good in my opinion.
HTH
10psi/1,000RPM seems to be the rule
My 87 Turbo-T has 3,200 or so miles on it. It is basically brand new! and a hot idle for me is abot 12 lbs.
I wouldnt worry about it!!
Oil pressure does not mean OIL FLOW!!!!!
Here's a related question I've wondered about
but have never seen an answer to;
When faced with selecting a pressure spring for
an oil pump, which one should be chosen?
50 psi? 60 or 70 psi? At what point does 'more'
become too much?
If your motor is fresh,...then the rule of thumb seems to be the more the better,...which is NOT always true..
You have to think about it in theory, such as,..
If you have a stock block you want to run at65-70 spring w/ low viscosity oil do to the pressure like 10w30 (not to mention) the turbo needs plenty of oil too)
If you have a motor with lots of miles you want less pressure,..more viscosity such as 50-60 spring with as much as 50 weight oil, do to bearing clearence at the crank journals.
However if your running a modified motor with high compression and so fourth, the choice is really up to you, but "IN THEORY" you want as much oil pressure and flow as you can get,...
And on a personal experence note I put a high pressure pump in a high mile motor once and blew some seals along w/ some other damage..
So all in all,... it depends on the application
At least this has been my experience!-GOOD LUCK-
I have just bought a stock 3.8 for my GN and am planning on a few mods like turbo, injectors, pump..... It runs great at 73,000 miles with no oil leaks. What oil would anyone suggest for this, 30 or 50 weight? Should it be TURBO APPROVED like the valvoline bottles say sometimes? Synthetic or What? Too many choices!
Thanx, John
I use the weight recommended on the sun visor. I always use synthetic and I change it twice per year. I don't run enough miles to change it every 2500.
Be aware that if the past owner has only been running non-synthetic oil, you may start with some oil leaks.
Patrick
'87 GN
I've owned Turbo Buicks for many years. The general consensus is Mobil 1 Synthetic as long as synthetic oil has been run in it previously.
Go to http://TurboOil.cjb.net for info about different oils and additives.