91GTABird

On my 91' GTA LB9 i keep the oil changed based on when it starts to look dirty (not the 3month 3000 mile basis). For the last 4-5 months is gets dirty at about 2-3K miles and the oil pressure runns at about 15-40psi. When i change it the Oil Press. runs at about 50psi for about 1000 miles and then for the next 2k it runs at about 20-30 depending on temp. and rpm. It also gets dirty and thinner for them last few thousand miles. Plus when i crank it up in the mornings it idle at about 1200 until it goes into closed loop mode then it idle @900 and etc. depending on coolant temp. Does this sound like a leaky injector? I love my car and care about it very much as like my last 3 3rd gens. and i try and keep it very well taken care of. I'd change the oil every weekend if it made me car last longer. I just want to make sure that im not worrying over nothing.

JayBernard

what kind of filter are you running? Frams are JUNK.... they may be pretty and have the little grip thing, but i wouldn't put them on my lawnmower...

is the car running rich? (black smoke, bad gas mileage) other than that, I'm clueless

91GTABird

Hmmmm....Fram "suregrip" the pretty one with the little grip thing. Thats all i've used. No smoke and gas mileage is about right the car. What would you recommend? What makes Frams junk?

thirdgen88

They're construction for one makes them junk... Cut one open and you'll find out.. I'd recommend a Wix or Purolator filter..

JayBernard

see : http://people.msoe.edu/~yoderw/oilfi...lterstudy.html

Click on Fram... then click on AC Delco and Wix

onebinky

iTrader: (1)

What did your typical oil change interval used to be? There's alot of contaminants in the oil besides dirt that you can't see.

Acids form from the reaction between moisture and the oil; iron, lead, and brass deposits from block and bearings and fuel contamination from blowby. Sludge also forms from the reaction of water and oil, and will stick in the engine when you change the oil.

Frams aren't all that great. They use a cheap paper filter media, and they use a faulty oil return check valve design. The check valve isn't suck a big deal on our motors where it screws on vertical, but alot of the cars where it lays at an angle or horizontal will start with 0 psi oil pressure because all the oil drains out of the filter when the car is off.

I use delco when I can find them, otherwise it's purolator. Not to sure on the other brands, but I need to start researching that because the delco's are getting almost impossible to find anymore.

D Stroy H8

Wow . Good info. I usually buy an STP filter, but this time I was forced to get a fram (autozone had nothing stocked for my car) and I am concerned! I think I shall be using the purolator premium plus from now on.

White91GTA

all i have used thus far is STP oil filters. last oil change i wanted to get the Delco filter but Autozone didn't have it. I am going to try and use the Delco's if i can find them.

robsgta

Hey BRI ,How many miles are on your car? Does you oil have a fuel smell to it? have you taken a look at any of your plugs?

f355bird

iTrader: (2)

if u have an oreilly's around where u live buy the micro guard oil filter it is made by puralator

jconrad

So what brand and weight oil are you running anyway?

91GTABird

135,000. I have always used pennzoil but my last oil change I used Castrol GTX 20w50. I always use 1 pint bottle of STP Oil treatmeant to thicken it up for the summer. Its been aout 3 weeks since my last oil change and my oil actually looks alot better than usuall its still clear enough that i have a hard time getting a reading. It doesnt really have a fuel smell to it.

Red Devil

20w50 plus an additive and it sounds like your oil is getting contaminated.

Do a compression test, you may find some troubling results.

onebinky

iTrader: (1)

Why 20w50? Do you have issues with low oil pressure?

D Stroy H8

10W30 is pretty much all one needs, unless you live in a harsh winter area or some places that has hotter summers than Las Vegas.

DJP87Z28

I used the Delco PF932 (2) qt filter for a total of six qts in the system using 10W30. Oil is like blood to a engine and that extra qt helps.

91GTABird

Our summers are worse than Las Vegas. Our humidy is awfull here. I would love some dry heat. The av. temp in june is about 95. I have never had a prob with 20w50 with any of my third gens. Why would 20w50 be bad?

onebinky

iTrader: (1)

Not nessesarily a bad thing, it's just much thicker than is needed. Could possibly take longer for the oil to thin to the point where it can pass freely thru the bearings, and because of the thick viscosity your gas mileage will be worse.

Usually you only see the 20w50 being used in loosely assembled race motors, or high mileage motors with loose bearing clearances.

I had to run 20w50 in my old 85 Z's motor to keep the oil pressure above 7psi at cruise.

In your hot climate, I'd run 10w30 if you can. No additives either, those are great at clogging up oil passages. If you are concerned with keeping the engine clean, run a synthetic oil. They are great for removing oil deposits and carbon buildup.

onebinky

iTrader: (1)

EDIT: And like I said above, make sure you change the oil every 3000 miles. There's alot of contaminants in the oil that you cannot physically see or smell. If you want to draw out the oil change intervals, the only way to be safe is with an oil analysis test. From what I hear, most labs will perform this for about $100.

D Stroy H8

Any clearance issues with the larger Delco PF932 filter? I would be worried about hitting the ground, but if it is nice and snug up there I'll be getting that one! I want 6 QTS sounds good for the 350

jconrad

I run the larger 'truck' filter on mine, with no problems. It doesn't even come down below the pan, really.

DJP87Z28

I have been using that (long) filter PF932 for 12yrs now both with my 305 and then with the 350. There is no clearance problems with its length and it fit up there real snug like. It cost more for the filter, but most Chevrolet Dealers have them (really it is a truck filter) and that extra qt of oil is helpful in my opinion.

Fire"Dutch"Bird

iTrader: (1)

1. Fram is not that bad at all.

2. The hotter the climat, the heavier the weight of the oil should be. (I'm running Synthetic 10W60 right now, altough our climat isn't hot at all!)

3. AC Delco UPF 1218 Ultraguard Gold is the oil filter of choice.
available at Pep Boys or GM dealer (part nr. 25322841).

mystikkal_69

iTrader: (2)

is the AC Delco UPF 1218 Ultraguard Gold a synthetic filter?

Fire"Dutch"Bird

iTrader: (1)

It has synthetic fibres, yes, it also has a teflon coated seal, no more oil leaking and easier to get it of!

91GTABird

My dipstick cap seems to come off every day. PCV valve maybe?

onebinky

iTrader: (1)

Either the crankcase can't vent, or you have excessive blow-by.

Test the PCV and the line going to it, and do a compression and leakdown test. Should find the problem with one of those three things.

91GTABird

Is blow-by compession leaking past my rings into my crank case?
Dont we have 2 pcv lines on the l98s and lb9s? What about a breather filter?

onebinky

iTrader: (1)

Thats my guess, is blowby.

One PCV line, and one breather line that goes from the passenger valve cover to the large TB port, IIRC.

Both sides would need to be clean to operate properly.

Spdfrk1990

Does anyone use a bigger oil filter Napa calls for the 1069 and the 1060 looks the same just longer. I looked in the book and the 1060 is for some 5.7 trucks and vans. Just wondering cause ide like to use a lil bigger filter. Also napa has out a new nascar filter called the spin flow suppose to flow better i dont know if it does but i use it. Maybe cause i work there lol.

robsgta

yeah this was higher up in the thread

Spdfrk1990

Wow i looked that filter up thats way too big. Im just gonna use 1 for a chevy truck the only thing diff internally is the bypass valve. It is like 1 or 1 1/2 inches taller.

Red Devil

ede

RD you're wasting your time

Guido

:withstupid:

91GTABird

I got a new filter today at autozone but it was an A/C Delco Duragard part #pf454. It was the same size as the PH30 Fram i always use but it was alittle shorter. I also noticed that on the throttle body the passnger side where the PCV hooks up there is no vaccum. I pulled the line from the TB and there isnt any vaccum coming from the hole.

thirdgen88

This has already been covered... The breather tube connects to that port... Your PCV is on the other side and connects to manifold vacuum on the base manifold.

89 Iroc Z

I didn't read the whole post, may have been mentioned but if you oil is thinning out you may have a leaking head or intake gasket and coolant may be getting into your oil.

robsgta

If water was in your oil you would know it. Your oil would look like chocolate milk not like oil.
Unfortuneatly I have blown enough head gaskets to know.

91GTABird

Thanks Thirdgen88. I read the post about the breather filter and which side to put in on but i just glanced over it and didnt remember. So basically my pcv is using my air filter as its own.

thirdgen88

No problem!