my oil pressure

[Sal Lubrano]

My 86 Gn with 105k has an oil pressure of 15 psi @160 degress. In the summer when the oil and water temp get up to 180 the oilt pressure is at 10 psi this is with 15-40 wieght oil. Should I run 20-50w oil as a crutch or stick with the 15-40?

 

[Red Regal T]

Sure, just move up to 20W50. I don't know what all this analness is about to run light oil. The only thing to be anal about is to change your oil at no more than 2000 miles. If you have suffered some oilpressure loss because of engine wear, simply use heavier oil, or take a few hours and change out your main and rod bearings. It's an easy job.

 

[2QUIK6]

10psi at idle is plenty, I wouldn't worry about it..if its at idle, you didn't say. 10psi for every 1000rpms is what is acceptable and I bet idle is not 1000rpms. Mines is lower than 10psi at idle when hot and has been for the last 10 years with only 40k on the clock when I first noticed it, 54k now.

 

[Sal Lubrano]

Yes, I was refering to idle.

 

[machinegun]

some people have different opinions on thicker oil. I personally use a 10w-40. The thinner oil will flow quicker than a thicker oil. I will provide less stress to the oil pump and the items driving it. Thinner oil will provide less friction than a thicker oil especially in tight clearance engines. You will notice many of todays performance engines actually use a 5w or 0w. Tighter clearances and thinner oil for less friction. So yes there is a difference. I personally do not use that thick of an oil. Synthetic seems to be thinner by nature anyway. Most buick engines work fine on 6 - 10 psi hot idle and 10 psi for every 1000 rpm. I shoot for 8 - 10 hot idle and 10 psi for every 1000 rpm. Hope this helps.

 

[bison]

If you have 60psi at 5000rpm you dont need to change anything. You have enough pressure at idle.

 

[QUIP'6']

make sure you run eos in there for safe keeping

 

[bison]

make sure you run eos in there for safe keeping

Or put a roller in and call it a day :biggrin:

 

[87GN_70GS]

Get the $11 Melling oil booster plate, part number P-20I from Autozone or Autozone.com

 

[DMan]

I dunno - 10 psi seems low. I used to have 10 psi at hot idle and my engine had 104k miles. That was 2004. Reason - wear, and my rear main bearing was a mess - down to the copper. Now, after a rebuild, my main bearing clearances are .002 (which is larger than largest factory spec), and hot idle (165-170 deg F) is 29-30 psi with 10W30 Mobil 1 at 900 rpm.

I guess people are anal because over time loose tolerances lead to further damage. What you want to avoid is damaging the crank journals. If you have to cut the crank to remove scoring, you reduce its strength. Better to do what Red Regal suggests and slap some new bearings in before the crank gets damaged.