lets talk oil pressure

Ok i am really leary of the whole buick oil pressure. I am used to dealing with chevy so this is all new to me.

today i changed the oil and put the normal 10w 30 vavoline in.

i was driving it around and i guess i had it out for about an hour. it was about 93 degrees out so really hot!

the engine was at 190 deg. and i was at an idle in drive. the oil gauge was reading 15 to 16. I though holy cow theres something wrong.

Like usual, as soon as i put it in neutral, it wen to about 20and once you touch the gas maybe 1300RPM its at 40. that sound more like it to me at idle, about 40psi.

the engine was built with .0025 main clearances so i know this is eating alot of pressure and maybe since it was so hot out it too was taking a lot of pressure i just don't know

does anyone have any comments?

please reassure me thanks bryan

 

Good!

Well actually, thats pretty good for a hot engine on a hot day with 10-30 oil.

 

with booster pump and using pennzoil 10w30 oil. at idle in gearwith engine temp at 200 i have about 12 psi.

my car does have 140k miles though but... it sounds normal from most of the guys on this board. you are using an aftermarket gauge i take it though...

I also should replace my timing cover (oil pump housing) but its not too too bad.

doh i forgot i was in the 455 area....
i run a 350..
Nate

 

the motor only has 500 miles on it though does that matter

 

With the .0025" clearances, I'd say thats normal....o No:

 

well i know for a fact it was built to factory clearances and i thought it was .0025 maybe .002. anyway wen it was still cool out in april and may in missouri about 65 70 deg, it would hold about 17 to 18.

is the heat breaking down the oil

if i went to synthetic 10w 30 would it hold a bit better pressure since it won't break down as easy?

thanks

 

The hot engine drop in oil pressure has more to do with the aluminum timing cover expanding faster than the steel oil pump gears.
The hot oil thinning out is a factor too, but the factory clearances were more like .0011"-.0015"...:shock:

 

i know they are around .002
and i always thought that was what factory was

a factory engine lets say with .0012 clearance still didn't run more than 12 psi at idle did they? with 10w30

so i'm ok right

i ran the motor again tonight when it cooled off and abnout same results ant 200deg the oil was 16 to 17 at 850RPM.

lets say i did have factory specs would this oil pressure be low or not?

 

Have you tried/thought about using 20w50?

 

That is pretty good oil pressure for 10-30 vavoline oil. That vavoline will come out like water when you drain it. I stopped running it after seeing how bad it breaks down. I run Mobil 1 synthedic oil 20w50 and never had a problem. With only 500 miles don't change to synthedic yet. Wait for a couple thousand miles. It will take for ever to break in other wise.