Zrated383

Hey guys...im really starting to get concerned about my L98. I bought my IROC from a man who bought it off a crack head lady who needed money desperatly. The car has 121k miles. It sat for 2 years before he picked it up. It starts right up every time, no puffs of smoke. It definitly needs to be tuned up though, but i have one big concern. The oil pressure gauge in the dash reads extremely low, and starts to fluxuate drastically. Is there any ways you guys can tell me the odds that my motor is shot? or my sending unit is just wacked out? i really would like to keep it but if the motor is shot i dont believe i can afford a new one.but also recommend me to a cheap motor rebuild or motor? thanks alot...

90rocz

I'd make sure I got the oil changed and replace the sender if I suspected false readings, they're cheap and easy to replace.
Usually as you engine shows wear, the pressure will be great "cold", but as it warms up it steadily drops, to like 10psi @ idle..

Zrated383

i have a new sending unit...but when i went to change it..the socket woudlnt fit over this metal jacket thats around the sending unit. i have the sending unit socket and it slips fine onto the new unit but it doesnt have this metal jacket around it thats on the car? and my concern is i dont know if i should do a tune up and then realize well my motor is shot and i just wasted my money! help!

Botch

I would check the base timing too. Running too much timing will make the oil overheat BAD. I have seen a lot of people run 12-16 degrees of base timing and have low oil pressure. The stock timing curve sucks, and they do make more power with the timing bumped up, but I wouldn't leave it advanced too much for daily use. The problem lyes in the fact that unless it pings the computer will put in a certain amount of timing, and if you adjust the base timing, you have just tricked the computer into putting too much in.

It might be your problem, might not.
Later,
Botch

90rocz

The "metal jacket is like a heat shield, it unsnaps and comes off the sender...I usually use a wrench on my "oil senders"...

dailydriver

my L03 has a similar issue, the oil pressure will be cranked when accelerating but dip and fluctuate when at idle.

kevin 2.8

wish my car had an oil pressure guage

mako350Z28

Hell, my oil pressure is like 50 psi at cold idle but drops to 0 psi when the engine is warm. According to the guage anyway.

90rocz

mako, does it make noise @ 0 psi? My gage kept reading lower and lower until it read "0", and I replaced it and it was back to normal..

daily, do you have a "High Volume/regular pressure" pump? If so that's why...Z28 pumps are High pressure regular volume...

When ever I have weird or dangerously low/high readings, I replace the "sender first"...

mako350Z28

Does what make noise? The oil pump?

aklim

If it were truely 0 psi, the engine would be rattling and banging around and it probably will run crappy.

91 GTA Ramair2

My L-98 has 125,000miles on it.....

I run 20w-50 standard oil........

20W-50 Maxlife oil 2 Qt oil filter........

Run's 70Psi cold Idles hot at 17psi......... this summer it will ne getting SAE60w VR1 Race oil......

as i'm not going to rebuild it this L-98 Right now......

But if your running some PH-30 aka 1/2Qr filter and some 5w-30 or 10w-30 crappy ooil for a v-8.......

you should have at least 10w-40 in it .....

try a ph-5 a 1QT Filter and some 20w-50 oil.......

still got Crappy oil psi......

try:
20w-50 oil with a 2QT filter as a last resort use SAE60w oil and the 2QT filter................

But keep in mind it's only going to last yopu about 2 maybe 3 summer's.......Then a rebuild or atleast Main & Rod's bearing's will be a must with anew HP oil pump...

Keep oil clean filter free Flowing......

aka

CHANGE YOUR OIL........

Don;'t use the Cheapest junk on the shelf.......

super tech is cheap but way way better then penzzoil or Quacker state.......

Casterol would work or valvoline......

I my self would run AMSOIL But thats exspensive......I use that in all my good engine's....

all the JSM/M&R truck's get AMSOIL SAE60W and huge oil filter's I also change filter's and oil offten....


GAS ENGINES:

oil filter every 2,00miles oil every 4,000 miles......

DIESEL ENGINES:
oil filter's and luber finder's every 2,000miles oil every 6,000miles......

That how i do it with my AMSOIL engine's....

All the company truck's are on the plan my 91 GTA will be on that plan......

S/S AMX dosen't get driven much so it got okl changed twice a summer once a winter while sitting and oil filter every time driven and all winter long every other time it was started.......

Now with regular normal oil I try to change oit every 2,00 -2,500 miles.... oil and filter.....

But i onlt got few beater's and the 87 GTA running conv. oil....

Irun synthetic 60w in every thing almost....

87 GTA might get 20w-50 AMSOIL.....

well the piont of this ranting is use good oil fairly heavy oil change it offyen engine will live a long time weather new or use with high miles and abuse....

so try replacing sender and running 20w-50 and PH-5 filter in summer and keep it clean...

mako350Z28

Oh, I know that the oil pump is working. I just need to replace the sending unit.

91 GTA Ramair2

your sending unit is at the back of your engine Back behind your dist..... there is a unit under your car by your oil filter but that won't effect your gauge...... But you could change it if you want....
it's recomemnd you change then both at the same time......

But it isn't really nessasary.....