mattbm2001

I purchased a 99 z28 camaro in early March. I've put 2000 miles on it (111k) in total now, I went out and purchased 1 gallon of Royal Purple 15w40, and 2 quarts of 10w30. After I purchased the oil some one told me it may be too thick for my car. I live in Southern California, and I do drive the car hard occasionally. It's not uncommon for me to get on the freeway and shift around 5k rpms.

Currently the car idles are operating temperature at 30psi oil pressure. I drive it 8 miles a day to work, 6 and a half which are freeway. I put on average 1500 miles on my car a month. Is my 4 quarts of 15-40 and 1 and a half of 10-30 too thick?

PNYDRPR

Your suppost to run 5w 30 synthetic

SSickLS1SS

just use 5w30

mattbm2001

It doesn't help that I was told that oil may be too thick right after putting it in my car. I was told about the issue right as I set my car down. I started it to make sure there were no leaks, car didn't warm up all the way and oil pressure was slightly higher. Should I drain it immediately and replace it with 5w30?

PNYDRPR

If it was mine I would you should probly change the oil and filter make sure you buy synthetic oil its best for your motor

mattbm2001

I went out and started the car, let it warm up then drove it around the neighborhood. At full operating temperature oil pressure at idle was about 38psi and at 5000 rpms 60psi. Again 4 quarts of 15w40 and 1 1/2 10w30 with a K&N Oil filter. Will it be okay to run this oil until it's due to be changed again? I change my oil on my cars at 3k or 3 months, whichever comes first, regardless.

strokeme

iTrader: (1)

I used to run 15w40 in my lt1 car to help with bringing up the oil pressure. It was fine, what i haven't done is mix weights like you did. Most my press. ever got i think was around 45-50 with a high volume pump. You'd be good with running just 5w30. IMO you should be fine, but idk if theres any other precautions with the ls1's. haven't had mine long enough to change oil in it.

mattbm2001

Well I guess I answered my own question. Started the car this morning from cold and could hear a light chattering from the lifters. Had my father who's a mechanic check it with a stethoscope and determined that's exactly where it's coming from. Luckily I haven't driven it more then about a half mile, buying RP 5w30 for it in a few minutes. One question though, what is the lowest acceptable oil pressure at idle?

Mr Incredible

What you have in there will be just fine for as long as you want to run it. Though the car was spec'd for 5w-30, it will run without harm with a 40w.

If you wanted to run all 5w or 10w or even 15w-40, your car would not blow up.

Oil pressure is not a bug to chase unless it's so low as to indicate you have oil pressure problems. High pressure with thicker oil only means you have less flow. Flow is good. More flow with a lighter oil is good, but the pressure isn't what a lot of people think it might oughta be.

You should read ALL of THIS.

myk

iTrader: (4)

Why did you mix the weights?

87v8rx7

as far as i know you should never mix weights.

ta420nk

First of all get rid of that k&n junk filter an get a wix.. Also read this .. http://www.bobistheoilguy.com/ Tons of good info.. It's better to be slightly thin on oil rather than thick

Head Hunter

iTrader: (14)

This

I know many people (including myself) who have run a heavier oil like Rotella T, etc. BITOG is the best resource you could have though

mattyj385

iTrader: (1)

you should never mix weights, and if i were you i would only run what it calls for, you dont need anything heavier since the tolerances are tight in the LS1s, if you were running an old small block or big block then yes use heavy oil but otherwise stick to what is recommended, and never mix weights because the molicules are different and dont mix

topgeer

iTrader: (2)

You really shouldnt mix different weights, and if your going to change ur oil every 3000 miles i wouldnt use royal purple that kind of over kill.

omarrakeen

iTrader: (2)

10-40 here not problem for 4 years

LS14ME2

15w40 is pretty thick oil. I have used 10w30 since break in... I know 5w30 is the preferred oil weight, but I think 10w30 helped quiet the engine down a bit...

COLDLZ

Old guy here, but it only takes 10lbs op per 1000 rpm. Low op is usually a pretty good sign of worn mains.

wav3form

iTrader: (1)

I run 0w30 Castrol German Formula and have had good results.

SOMbitch

iTrader: (8)

What some of you guys are missing is that on a motor with wear, the tolerances are bigger and heavier oil is beneficial. IMO if you dip below 30psi hot idle you should definitely go to a thicker oil. I would really prefer to see 40psi.

BTW Bondurant driving school runs nothing but 50wt in their vettes now because they were spinning so many bearings.

I think your ok running a heavier oil to get proper pressure.

EDIT: HKE told me to run 15w-50 in my 403.