tex1994

ok i recently bought a 1998 z28 camaro and when i first bought it everything was going good it ran strong and still runs strong but i think the oil pump is starting to go bad because when i start it up it sits at like 40 on the oil pressure gauge and i hear a little tapping noise like the lifters arent getting enough oil but when it warms up the oil pressure drops to like 20 and the tapping mellows out but i can still hear it a little bit and when im driving down the road and even on the highway the oil pressure is sitting at like 30 im just wanting to know like what should my oil pressure be reading when i start it up and when it cools down im putting it in the shop tomorrow but i still would like to know thanks

2DMNFST

iTrader: (16)

My 99 TA ussually sits at 20-40 psi but only at idle and when it is completely warmed up. Then when I get on it, it jumps up to 45-50 psi. When its cold it ussually sits at 45-50 psi at idle.

AznMuscle

iTrader: (7)

Same here. When I really get in it, it jumps up with the RPMS, up to around 60-80 psi I think. Idle is right around 40-50.

tex1994

so there is definitley something up with my oil pump it sounds like

AznMuscle

iTrader: (7)

Could be. I don't know what else it could be..hopefully someone can chime in. I want to say oil pressure sending unit, but I am not sure. All I know is that, that lil fugger is easy to break...but I don't know what the actual problems arising from that are.

Texas 02 Z28

iTrader: (14)

Mine sits at around 50psi at idle, then climbs with the rpms.

tex1994

so i took it to my mechanic today and he said it sounds like some play in the bearings or the wrist pin he said that gm is known for some wrist pin failure so basically i think im looking at getting a new motor (hooray for me)

Ice78Transam

iTrader: (1)

X2.
45-50 psi idle up to about 70 max psi (as far as i can tell from my super accurate GM gauge)

99345hp

wrist pin failure? I dont think thats right. What you are hearing at cold startup is most likely piston slap. That is very common with these engines. It doesn't mean you need a new engine either. Lower than normal oil pressure will cause lifter noise, so I would recommend changing out the oil pump and see what the motor sounds like.

Wesmanw02

iTrader: (4)

How many miles are on this engine??

Your mechanic sounds old school, I haven't heard of any issues with wrist pins on LS series engines.

Its probably just valvetrain clatter (its much more audible since our blocks and heads are aluminum) or piston slap, both of which are considered normal and are nothing to worry about.

If your oil pressure drops below 20PSI, is very inconsistant, or flutters, then thats something to worry about.

TAtoad

iTrader: (22)

what weight oil are you using? mine sits right under 40 psi at idle. over 70 psi when i gun it

Wesmanw02

iTrader: (4)

Same here. And thats with 10W-30 Mobil 1 Synthetic.

thebulgd

iTrader: (6)

Oil filter. When was the last time you changed the oil and what type of filter did you use? Start with the small easy/cheap stuff. My oil pressure would drop and would be fine after an oil changed, weird butt true. Oil filter.

tex1994

well seeing as i just got the car last friday i recently did an oil change on it this past saturday and i used castrol syntec 5w-30 with a fram filter but the oil was pretty black when i changed it so no telling how long it went without a change the car has 94k on it but when im sitting there at idle with the car warmed up im a little under 20psi when i get on the highway im riding at about 25 to 30 psi now i may be a little paranoid seeing as this is my first z28 and im in love with it

tex1994

and thanks for all the help

SOMbitch

iTrader: (8)

Mine was right at 40 idling at 230* coolant temp after the H/C went on.... Radiater fixed that and I now run no lower than 45 at any time.

Don't know this to be fact but have read 22 is all that is required to fully pump up lifters but I would think spring pressure may change that.

Somebody school me........

Vogos97c5

iTrader: (6)

The filter can make a big difference. I put on a mobil 1 filter on my old car, figured since I used mobil 1 oil, why not. Pfffft, oil pressure was cut in half at idle. I think I was running like 20 psi or maybe lower with the mobil 1 filter. Swapped it out, can't remember for which kind, and it went right back up to 40+ psi at idle.

Wesmanw02

iTrader: (4)

Perhaps you got a defective filter.

I run Mobil 1 filters on both my cars, no issues with low oil pressure at all.

Vogos97c5

iTrader: (6)

Well, this was probably 7 or so years ago, perhaps they have changed since then? At the time I think other people were having the same issue. I've just never tried them again since that experience. Anyway, just saying that the filter can have an affect on the psi.

LS1Silverado05

iTrader: (41)

PSI seems a little low to me....

However...I wouldn't go rebuilding a motor just yet. I think your mechanic while well intentioned, probably doesn't know the LSX family like most of us do. Its quite common to hear some clatter and piston slap especially on a cold motor...

I new oil pump wouldnt cost you much...(but the cam you will want to put in while you are in there might...haha)